Methods of treating or preventing autoimmune diseases with 2,4-pyrimidinediamine compounds

Description

2. FIELD OF The invention [0001] The present invention relates generally to 2,4-pyrim.idinediamine compounds and pharmaceutical compositions comprising the compounds for use in the treatment or prevention of antoimmune diseases and/or the symptoms associated therewith.

3. BACKGROUND OF The invention [0002] Crosslinking of Fc receptors, such as the high affinity receptor for IgE (FcERI) and/or the high affinity reœptor for IgG (FcyRI) activates a signaling cascade in mast, basophil and other immune cells that results in the release of chemical mediators responsible for numerous adverse events. For example, such crosslinking leads to the release of preformed mediators of Type I (immediate) anaphylactic hypersensitivity reactions, such as histamine, from storage sites in granules via degranulation. It also leads to the synthesis and release of other mediators, including leukotrienes, prostaglandins and platelet-activating factors (PAFs), that play important roles in inflammatory reactions. Additional mediators that are synthesized and released upon crosslinking Fc receptors include cytokines and nitric oxide.

[0003] The signaling cascade(s) activated by crosslinking Fc receptors such as FceRI and/or FcyRI comprises an array of cellular proteins. Among the most important intracellular signal propagators are the tyrosine kinases. And, an important tyrosine kinase involved in the signal transduction pathways associated with crosslinking the FœRI and/or FcyRI receptors, as well as other signal transduction cascades, is Syk Kinase (seeValent et al., 2002, Intl. J. Hematol. 75(4):257-362 for review).

[0004] As the mediators released as a result of FceRI and FcyRI receptor cross-linking are responsible for, or play important roles in, the manifestation of numerous adverse events, the availability of compounds capable of inhibiting the signaling cascade(s) responsible for their release would be highly desireable. Moreover, owing to the critical role that Syk kinase plays these and other receptor signaling cascade(s), the availability of compounds capable of inhibiting Syk kinase would also be highly desirable.

[0005] WO 01/600,816 describes inhibitors of kinases. WO 01/64656 describes 2,4,di(hetero)arylamino(-oxy)-5 pyrimidines as antineoplastic agent. WO 00/39101 describes pyrimidine derivatives which are useful as anticancer agents. US-A-5958935 describes substituted 2-anilinopyrimidines useful as protein kinase inhibitors. WO 01/47897 describes N-heterocycliccompoundsthatblockcytokine productionviainhibitionofp38 kinase.WO 00/58305 describescompounds which are modulators of chemokine receptor activity. WO 03/063794 which was published on 7 August 2003 describes 2,4-pyrimidine diamine compounds that inhibit the IgE and/or IgG receptors signalling cascades that lead to the release of chemical mediators. WO 03/078,404, which was published on 25 September 2003 describes pyrimidine derivatives useful in disorders where zap-70 and/or Syk inhibition plays a role or caused by a malfunction of signal cascades connected with FAK. WO 03/076,437, published 18 September 2003, describes CDK-inhibiting 2-heteroarylpyrimidines. WO 03/002,544, published 9 January 2003 describes N-heterocyclic inhibitors of TNF-a expression. WO 03/026,664, published 3 April 2003, describes 2-phenylamino-4-(5-pyrazolylamino)-pyrimidine derivatives as kinase inhibitors, in particular, SRC kinase inhibitors. GB-A-2,373,186 describes pharmaceutical combinations of a CCR3 antagonist and a compound which is useful in treatment of asthma, allergic disease or inflammation.

4. SUMMARY OF The invention [0006] The compounds used in the inventíon generally comprise a 2,4-pyrimidinediannine "core” having the following structure and numbering convention:

<img file="IS2923B_D0001.tif" /> [0007] The compounds used in The invention are substituted at the C2 nitrogen (N2) to form a secondary amine and are further substituted at the C5 position. The compounds are also substituted at the C4 nitrogen (N4), to form a secondary amine. The substituent at N2, as well as the optional substituents at the other positions, may range broadly in character and physico-chemical properties. For example, the substituent(s) may be a branched, straight-chained or cyclic alkyl,

<img file="IS2923B_D0002.tif" />

a branched, straight-chained or cyclic heteroalkyl, a mono- or polycyclic aryl, a mono-or polycyclic heteroaryl or combinations of these groups. These substituent groups may be further substituted, as will be described in more detail below. [0008] The N2 and/or N4 substituents are attached directly to their respective nitrogen atoms [0009] The substituents at the N2, N4 and C5 positions, may be further substituted with one or more of the same or different substituent groups. The nature of these substituent groups may vary broadly. Non-limiting examples of suitable substituent groups include branched, straight-chain or cyclic alkyls, mono- or polycyclic aryls, branched, straight-chain or cyclic heteroalkyls, mono- or polycyclic heteroaryls, halos, branched, straight-chain or cyclic haloalkyls, hydroxyls, oxos, thioxos, branched, straight-chain or cyclic alkoxys, branched, straight-chain or cyclic haloalkoxys, trifluorometh-oxys, mono- or polycyclic aryloxys, mono- or polycyclic heteroaryloxys, ethers, alcohols, sulfides, thioethers, sulfanyls (thiols), imines, azos, azides, amines primary, secondary and tertiary), nitriles (any isomer), cyanates (any isomer), thiocyanates (any isomer), nitrosos, nitros, diazos, sulfoxides, sulfonyls, sulfonic acids, sulfamides, sulfonamides, sulfamic esters, aldehydes, ketones, carboxylic acids, esters, amides, amidines, formadines, amino acids, acetylenes, carbamates, lactones, lactams, glucosides, gluconurides, sulfones, ketals, acetals, thioketals, oximes, oxamic acids, oxamic esters, etc., and combinations of these groups. Substituent groups bearing reactive functionalities may be protected or unprotected, as is well-known in the art.

[0010] The present invention provides a 2,4-pyrimidinediamine compound for use in the treatment of an autoimmune disease otherthan Crohn’s disease, ulcerative colitis, inflammatory bowel, and idiopathic inflammatory bowel disease, wherein the 2,4-pyrimidinediamine compound is:

a compound of structural formula (I):

<img file="IS2923B_D0003.tif" /> or a salt, hydrate, solvate and/or an N-oxide thereof, wherein:

L¹ and L² are each, a direct bond;

R² is selected from the group consisting of phenyl mono substituted at the 3- or 5- position with an R⁸ group, phenyl di- or tri-substituted with one or more of the same or different R⁸ groups and an optionally substituted heteroaryl as defined below;

R⁴ is selected from the group consisting of phenyl substituted with one or more of the same or different R⁸groups and an optionally substituted heteroaryl as defined below; wherein, for R² and R⁴, each of said optionally substituted heteroaryl, independent of one another, is selected from the group consisting of: <img file="IS2923B_D0004.tif" />

<img file="IS2923B_D0005.tif" />

<img file="IS2923B_D0006.tif" />

<img file="IS2923B_D0007.tif" />

<img file="IS2923B_D0008.tif" /> wherein:

p is an integer from one to three;

each — independently represents a single bond or a double bond;

R³⁵ is hydrogen or R⁸;

X is selected from the group consisting of CH, N and N-O;

each Y is independently selected from the group consisting of O, S and NH;

each Y¹ is independently selected from the group consisting of O, S, SO, SO₂, SONR³⁶, NH and NR³⁷;

each Y² is independently selected from the group consisting of CH, CH₂, 0, S, N, NH and NR³⁷;

R³⁶ is hydrogen or alkyl;

R³⁷ is selected from the group consisting of hydrogen and a progroup selected from the group consisting of aryl, arylalkyl, heteroaryl, R^a, R^b, -CR^aR^b-0-C(0)R⁸, -CR^aR^b-O-PO(OR⁸)2, -CH2-O-PO(OR⁸)2, -CH₂-PO(OR⁸)2, -C (O)-CR^aR^b-N(CH3)₂, -CR^aR^b-O-C(O)-CR^aR^b-N(CH3)2, -C(0)R⁸, -C(O)CF3 and -C(O)-NR⁸-C(O)R⁸;

R³⁸ is selected from the group consisting of alkyl and aryl;

A is selected from the group consisting of Ο, NH and NR³⁸;

R⁹, R¹⁰, R¹¹ and R¹² are each, independently of one another, selected from the group consisting of alkyl, alkoxy, halogen, haloalkoxy, aminoalkyl and hydroxyalkyl, or, alternatively, R⁹ and R¹⁰ and/or R¹¹ and R¹² are taken together to form a ketal;

each Z is selected from the group consisting of hydroxyl, alkoxy, aryloxy, ester, and carbamate;

Q is selected from the group consisting of -OH, -OR⁸, -NR^CR^C, -NR³⁹-CHR⁴⁰-R^b, -NR³⁹-(CH₂)_m-R^b and -NR³⁹-C (O)-CHR⁴⁰-NR^cR^c;

R³⁹ and R⁴⁰ are each, independently of one another, selected from the group consisting of hydrogen, alkyl, aryl, alkylaryl, arylalkyl and NHR⁸;

R⁵ is selected from the group consisting of-CN, -NC,, fluoro, (C1-C3) haloalkyl, (C1-C3) perhaloalkyl, (C1-C3) haloalkoxy, (C1-C3) perhaloalkoxy, -C(0)R^a, -C(0)0R^a, -C(O)CF₃ and -C(0)0CF₃; .

R⁶ is hydrogen;

R⁸ is selected from the group consisting of R^e, R^b, R^e substituted with one or more of the same or different R^a or R^b, -0R^a substituted with one or more of the same or different R^a or R^b, -B(OR^a)2, -B(NR^CR^C)2, -(CH₂)_m-R^b, -(CHR^a)m-R^b, -0-(CH2)_m-R^b, -S-(CH2)m-R^b, -0-CHR^aR^b, -0-CR^a(R^b)2, -0-(CHR^a)m-R^b, -O- (CH2)_m-CH[CH₂)_mR^b] R^b, -S-(CHR^a)m-R^b, -C(0)NH-(CH2)_m-R^b, -C(0)NH-(CHR^a)m-R^b, -O-(CH2)_m-C(O)NH-(CH₂)_m-R^b, -S-(CH2)m-C(0) NH-(CH2)m-R^b, -0-(CHR^a)m-C(0)NH-(CHR^a)m-R^b, -S-(CHR^a)m-C(O)NH-(CHR^a)m-R^b, -NH-(CH2)_m-R^b, -NH-(CHR^aVR^b, -N[(CH2)mR^b]2, -NH-C(O)-NH-(CH₂)_m-R^b, -NH-C(O)-(CH2)m-CHR^bR^b and -NH-(CH2)_m-C (O)-NH-(CH₂)_m-R^b;

each R^a is independently selected from the group consisting of hydrogen, (C1-C6) alkyl, (C3-C8) cycloalkyl, (C4C11) cycloalkylalkyl, (C5-C10) aryl, (C6-C16) arylalkyl, 2-6 membered heteroalkyl, 3-8 membered cycloheteroalkyl, 4-11 membered cycloheteroalkylalkyl, 5-10 membered heteroaryl and 6-16 membered heteroarylalkyl;

each R^b is a suitable graup independently selected from the group consisting of =0, -OR^d, (C1-C3) haloalkyloxy, =S, -SR^d, =NR^d, =N0R^d, -NR^CR^C, halogen, -CF3, -CN, -NC, -OCN, -SCN, -NO, -NO2, =N2, -N3, -S(O)R^d, -S(O)2R^d, -S(0)20R^d, -S(O)NR^CR^C, -S(O)2NR^cR^c, -OS(O)R^d, -0S(0)2R^d, -0S(0)20R^d, -OS(O)₂NR^aRc, _c(O)R^d, -C(0)0R^d,

<img file="IS2923B_D0009.tif" />

-C(O)NRCRc -C(NH)NR^CR^C, -C(NR^a)NR^cR^c, -C(NOH)R^a, -C(NOH)NR^CR^C, -OC(O)R^d, -OC(O)OR^d, -OC(O)NR^CR^C, -OC(NH)NR^CR^C, -OC(NR^a)NR^cR^c, -[NHC(O)]„R^d, -[NR^aC(O)]„R^d, -[NHC(O)]nOR^d, -[NR^aC(O)]nOR^d, -[NHC (O)]nNR^cR^c, -[NR^aC(O)]nNR^cR^c, -[NHC(NH)]nNR^cR^c and -[NR^aC(NR^a)]nNR^cR^c;

each R^c is independently R^a, or, alternatively, two R^c are taken together with the nitrogen atom to which they are bonded to form a 5 to 8-membered cycloheteroalkyl or heteroaryl which may optionally include one or more of the same or different additional heteroatoms and which may optionally be substituted with one or more of the same or different R^a or suitable R^b groups;

each R^d is independently an R^a;

each R^e is independently selected from the group consisting of (C1-C6) alkyl, (C3-C8) cycloalkyl,-(C4-C11) cy-cloalkylalkyl, (C5-C10) aryl, (C6-C16) arylalkyl, 2-6 membered heteroalkyl, 3-8 membered cycloheteroalkyl, 4-11 membered cycloheteroalkylalkyl, 5-10 membered heteroaryl and 6-16 membered heteroarylalkyl;

each m is independently an integerfrom 1 to 3; and each n is independently an integer from 0 to 3;

or the 2,4-pyrimidinediamine compound is a compound selected from the group consisting of 7.4.214 through 7.4.244, 7.4.250 through 7.4.252,7.4.256 through 7.4.258,7.4.262 through 7.4.269,7.4.272 through 7.4.276,7.4.278 through 7.4.280, 7.4.283 through 7.4.289, 7.4.296, 7.4.298 through 7.4.302, 7.4.304, 7.4.305, 7.4.308 through 7.4.313, 7.4.315, 7.4.317, and 7.4.318;

with the provisos that in formula (I):

(1) when R² is a substituted phenyl, then R⁵ isotherthan cyano or-C(O)NHR, where R is hydrogenor(C1-C6) alkyl;

(2) when R² and R⁴ are each independently a substituted or unsubstituted indole, then the R² and R⁴ are attached to the remainder of the molecule viaa ring carbon atom; and (3) the compound is not <img file="IS2923B_D0010.tif" />

Prodrugs of the 2,4-pyrimidinediamine compounds are described. Such prodrugs may be active in their prodrug form, or may be inactive until converted under physiological or other conditions of use to an active drug form. In the prodrugs, one or more functional groups of the 2,4-pyrimidinediamine compounds are included in pro-moieties that cleave from the molecule under the conditions of use, typically by way of hydrolysis, enzymatic cleavage or some other cleavage mechanism, to yield the functional groups. For example, primary or secondary amino groups may be included in an amide promoiety that cleaves under conditions of use to generate the primary or secondary amino group. Thus, the prodrugs include special types of protecting groups, termed "progroups," masking one or more functional groups of the 2,4-pyrimidinediamine compounds that cleave under the conditions of use to yield an active 2,4-pyrimidinediamine drug compound. Functional groups within the 2,4-pyrimidinediamine compound that may be masked with progroups for inclusion in a promoiety include, but are not limited to, amines (primary and secondary), hydroxyls, sulfanyls (thiols), carboxyls, carbonyls, phenols, catechols, diols, alkynes, phosphates, etc. Myriad progroups suitable for masking such functional groups to yield promoieties that are cleavable under the desired conditions of use are known in the art. An of these progroups, alone or in combinations, may be included in the Prodrugs of The invention. Specific examples of promoieties that yield primary or secondary amine groups that can be included in the prodrugs include, but are not limited to amides, carbamates, imines, ureas, phosphenyls, phosphoryls and sulfenyls. Specific examples of promoieties that yield sulfanyl groups that can be included in the prodrugs include, but are not limited to, thioethers, for example S-methyl derivatives (monothio, dithio, oxythio, aminothio acetals), silyl thioethers, thioesters, thiocarbonates, thiocarbamates, asymmetrical disulfides, etc. Specífic examples of promoieties that cleave to yield hydroxyl groups that can be included in the prodrugs include, but are not limited to, sulfonates,

<img file="IS2923B_D0011.tif" />

esters and carbonates. Specific examples of promoieties that yield carboxyl groups that can be included in the prodrugs included, but are not limited to, esters (including silyl esters, oxamic acid esters and thioesters), amides and hydrazides.

[0011] In one example, the prodrugs are compounds according to structural formula (I) in which the protecting group of R^c and R^d is a progroup.

[0012] Replacing the hydrogens attached to N2 and N4 in the 2,4-pyrimidinediamines of structural formula (I) with substituents adversely affects the activity of the compounds. However, as will be appreciated by skilled artisans, these nitrogens may be included in promoieties that, under conditions of use, cleave to yield 2,4-pyrimidinediamines according to structural formula (I). Thus, in another example, the prodrugs are compounds according to structural formula (II):

<img file="IS2923B_D0012.tif" /> including salts.hydrates, solvates and N-oxides thereof, wherein:

R², R⁴, R⁵,R⁶, L¹ and L² are as previously defined for structural formula (I); and

R^2b and R^4b are each, independently of one another, a progroup.

[0013] In another aspect, the present invention provides compositions for use according to The invention, the composition comprising one or more compounds and an appropriate carrier, excipient or diluent The exact nature of the carrier, excipient or diluent will depend upon the desired use for the composition, and may range from being suitable or acceptable for veterinary uses to being suitable or acceptable for human use.

[0014] Intermediates useful for synthesizing the 2,4-pyrimidinediamine compounds and prodrugs are described. In one example, the intermediates are 4-pyrimidineamines according to structural formula (III):

<img file="IS2923B_D0013.tif" /> including salts, hydrates, solvates and N-oxides thereof, wherein R⁴, R⁵, R⁶and L²areas previouslydefinedforstructural formula (I); LG is a leaving group such as, for example, -S(O)₂Me, -SMe or halo (e.g., F, Cl, Br, I); and R⁴⁰ is hydrogen or a progroup.

[0015] In another example, the intermediates are 2-pyrimidineamines according to structural formula (IV): <img file="IS2923B_D0014.tif" />

<img file="IS2923B_D0015.tif" />

<img file="IS2923B_D0016.tif" />

<img file="IS2923B_D0017.tif" />

including salts, hydrates, solvatesand N-oxides thereof, wherein R², R⁵, R⁶and L¹ areas previously definedforstructural formula (I); LG is a leaving group, such as, for example, -S(O)₂Me, -SMe or halo (e.g., P, Cl, Bar,l) and R^2c is hydrogen or a progroup.

[0016] In yet another example the intermediates are 4-amino- or 4-hydroxy-2-pyrimidineamines according to structural formula (V):

<img file="IS2923B_D0018.tif" /> including salts, hydrates, solvatesand N-oxides thereof, wherein R², R⁵, R⁶and L¹ areas previouslydefinedforstructural formula (I), R⁷ is an amino or hydroxyl group and R^2c is hydrogen or a progroup.

[0017] In another example, the intermediates are N4-substituted cytosines according to structural formula (VI): <img file="IS2923B_D0019.tif" /> including salts, hydrates, solvates and N-oxides thereof, wherein R⁴ R⁵, R⁵ and L² are as previously defined for structural formula (I) and R^4c is hydrogen or a progroup.

[0018] Methods of synthesizing the 2,4-pyrimidinediamine compounds and prodrugs are described. In one example, the method involves reacting a 4-pyrimidineamine according to structural formula (III) with an amine of the formula HR²⁶N-L¹-R², where L¹, R² and R^2c are as previously defined for structural formula (IV) to yield a 2,4-pyrimidinediamine according to structural formula (I) or a prodrug according to structural formula (II).

[0019] In another example, the method involves reacting a 2-pyrimidineamine according to structural formula (IV) with an amine of the formula R⁴-L²-NHR⁴⁰ where L⁴, R⁴ and R^4c are as previously defined for structural formula (III) to yield a 2,4-pyrinnidinediamine according to structural formula (I) or a prodrug according to structural formula (II).

[0020] In yet another example, the method involves reacting a 4-amino-2-pyrimidineamine according to structural formula (V) (in which R⁷ is an amino group) with an amine of the formula R⁴-L²-NHR^4c, where L², R⁴ and R^4c are as defined for structural formula (III), to yield a 2,4-pyrimidinediamine according to structural formula (I) or a prodrug according to structural formula (II). Alternatively, the 4-amino-2-pyrimidineamine may be reacted with a compound of the formula R⁴-L²-LG, where R⁴ and L² are as previously defined for structural formula (I) and LG is a leaving group.

[0021] In still another example, the method involves halogenating a 4-hydroxy-2-pyrimidineamine according to structural formula (V) (R⁷ is a hydroxyl group) to yield a 2-pyrimidineamine according to structural formula (IV) and reacting this pyrimidineamine with an appropriate amine, as described above.

[0022] In yet another example, the method involves halogenating an N4-substituted cytosine according to structural formula (VI) to yield a 4-pyrimidineamine according to structural formula (III) and reacting this pyrimidineamine with an appropriate amine, as described above.

[0023] The 2,4-pyrimidinediamine compounds used in The invention are potent inhibitors of degranulation of immune cells, such as mast, basophil, neutrophil and/or eosinophil cells. Thus, methods are described of regulating, and in particular inhibiting, degranulation of such cells. The method generally involves contacting a cell that degranulates with an amount of a 2,4-pyrimidinediamine compound or prodrug , or an acceptable salt, hydrate, solvate, N-oxide and/or composition thereof, effective to regulate or inhibit degranulation of the cell. The method may be practiced in in vitro contexts or in in vivo contexts as a therapeutic approach towards the treatment or prevention of diseases characterized by, caused by or associated with cellular degranulation.

[0024] While not intending to be bound by any theory of operation, biochemical data confirm that the 2,4-pyrimidine-

<img file="IS2923B_D0020.tif" />

<img file="IS2923B_D0021.tif" />

diamine compounds exert their degranulation inhibitory effect, at least in part, by blocking or inhibiting the signal transduction cascade(s) initiated by crosslinking of the high affinity Fc receptors for IgE ("FceRI") and/or IgG ("FcyRI"). Indeed, the 2,4-pyrimidinediamine compounds are potent inhibitors of both FceRI-mediated and FcyRI-mediated degranulation. As a consequence, the 2,4-pyrimidine compounds may be used to inhibit these Fc receptor signalling cascades in any cell type expressing such FceRI and/or FcyRI receptors including but not limited to macrophages, mast, basophil, neutrophil and/or eosinophil cells.

[0025] The methods also permit the regulation of, and in particular the inhibition of, downstream processes that result as a consequence of activating such Fc receptor signaling cascade(s). Such downstream processes include, but are not limited to, FceRI-mediated and/or FcyRI-mediated degranulation, cytokine production and/or the production and/or release of lipid mediators such as leukotrienes and prostaglandins. The method generally involves contacting a cell expressing an Fc receptor, such as one of the cell types discussed above, with an amount of a 2,4-pyrimidinediamine compound or prodrug or an acceptable salt, hydrate, solvent, N-oxide and/or composition thereof, effective to regulate or inhibit the Fc receptor signaling cascade and/or a downstream process effected by the activation of this signaling cascade. The method may be practiced in in vitro contexts or in in vivo contexts as a therapeutic approach towards the treatment or prevention of diseases characterized by, caused by or associated with the Fc receptor signaling cascade, such as diseases effected by the release of granule specific chemical mediators upon degranulation, the release and/or synthesis of cytokines and/or the release and/or synthesis of lipid mediators such as leukotrienes and prostaglandins. of lipid mediators such as leukotrienes and prostaglandins.

[0026] The present invention provides the defined 2,4-pyrimidine compounds for use in the treatment and/or prevention of diseases characterized by, caused by or associated with the release of chemical mediators as a consequence of activating Fc receptor signaling cascades, such as FceRI and/orFcyRI- signaling cascades. The methods may be practiced in animals in veterinary contexts or in humans. The methods generally involve administering to an animal subject or human an amount of a 2,4-pyrimidinediamine compound or prodrug or an acceptable salt, hydrate, solvate, N-oxide and/or composition thereof, effective to treat or prevent the disease. As discussed previously, activation of the FœRI or FcyRI receptor signaling cascade in certain immune cells leads to the release and/or synthesis of a variety of chemical substances that are pharmacological mediators of a wide variety of diseases. Any of these diseases may be treated or prevented.

[0027] For example, in mast cells and basophil cells, activation of the FceRI or FcyRI signaling cascade leads to the immediate (í.e., within 1 -3 min. of receptor activation) release of preformed mediators of atopic and/or Type I hypersensitivity reactions (e.g., histamine, proteases such as tryptase, etc.) via the degranulation process. Such atopic or Type I hypersensitivity reactions include, but are not limited to, anaphylactic reactions to environmental and other allergens (e.g., pollens, insectand/oranimal venoms, foods, drugs, contrastdyes, etc.), anaphylactoid reactions, hayfever, allergic conjunctivitis, allergic rhinitis, allergic asthma, atopic dermatitis, eczema, urticaria, mucosal disorders, tissue disorders and certain gastrointestinal disorders.

[0028] The immediate release of the preformed mediators via degranulation is followed by the release and/or synthesis of a variety of other chemical mediators, including, among other things, platelet activating factor (PAF), Prostaglandins and leukotrienes (e.g., LTC4) and the de novo synthesis and release of cytokines such as TNFa, IL-4, IL-5, IL-6, IL-13, etc. The first of these two processes occurs approximately 3-30 min. following receptor activation; the latter approximately 30 min. - 7 hrs. following receptor activation. These "late stage" mediators are thought to be in part responsible for the chronic symptoms of the above-listed atopic and Type I hypersensitivity reactions, and in addition are chemical mediators of inflammation and inflammatory diseases (e.g., osteoarthritis, inflammatory bowel disease, ulcerative colitis, Crohn’s disease, idiopathic inflammatory bowel disease, irritable bowel syndrome, spastic colon, etc.), low grade scarring (e.g., scleroderma, increasedfibrosis, keloids, post-surgicalscars, pulmonaryfibrosis, vascularspasms, migraine, reperfusion injury and post myocardial infarction), and sicca complex or syndrome. All of these diseases may be treated or prevented. [0029] Additional diseases which cam be treated or prevented include diseases associated with basophil cell and/or mastcell pathology. Examplesof such diseasesinclude, but are not limited to, diseasesoftheskinsuch as scleroderma, cardiac diseases such as post myocardial infarction, pulmonary diseases such as pulmonary muscle changes or remodeling and chronic obstructive pulmonary disease (COPD) and diseases of the gut such as inflammatory bowel syndrome (spastic colon).

[0030] The 2,4-pyrimidinediamine compounds used in The invention are also potent inhibitors of the tyrosine kinase Syk kinase. Methods of regulating, and in particular inhibiting, Syk kinase activity are described. The method generally involves contacting a Syk kinase or a cell comprising a Syk kinase with an amount of a 2,4-pyrimidinediamine compound or prodrug of The invention, or an acceptable salt, hydrate, solvate, N-oxide and/or composition thereof, effective to regulate or inhibit Syk kinase activity. In one example, the Syk kinase is an isolated or recombinant Syk kinase. In another example, the Syk kinase is an endogenous or recombinant Syk kinase expressed by a cell, for example a mast cell or a basophil cell. The method may be practiced in in v/'fro contexts or in in vwocontexts as a therapeutic approach towards the treatment or prevention of diseases characterized by, caused by or associated with Syk kinase activity.

[0031 ] While not intending to be bound by any particular theory of operation, it is believed that the 2,4-pyrimdinediamine compounds inhibit cellular degranulation and/or the release of other chemical mediators primarily by inhibiting Syk kinase that gets activated through the gamma chain homodimer of FœRI (see, e.g., FIQ. 2). This gamma chain homodimer is shared by other Fc receptors, including FcyRI, FcyRIII and FcaRI. For all of these receptors, intracellular signal transduction is mediated by the common gamma chain homodimer. Binding and aggregation of those receptors results in the recruitment and activation of tyrosine kinases such as Syk kinase. As a consequence of these common signaling activities, the 2,4-pyrimidinediamine compounds described herein may be used to regulate, and in particular inhibit, the signaling cascades of Fc receptors having this gamma chain homodimer, such as FceRI, FcyRI; FcyRIII and FcaRI as well as the cellular responses elicited through these receptors.

[0032] Syk kinase is known to play a critical role in other signalling cascades. For examples, Syk kinase is an effector of B-cell receptor (BCR) signaling (Turneret al„ 2000, Immunology Today 21:148-154) and is an essential component of integrin beta(1), beta(2) and beta(3) signaling in neutrophils (Mocsai et al., 2002, Immunity 16:547-558). As the 2,4-pyrimidinediamine compounds described herein axe potent inhibitors of Syk kinase, they can be used to regulate, and in particular inhibit, any signaling cascade where Syk plays a role, such as, fore example, the Fc receptor, BCR and integrin signaling cascades, as well as the cellular responses elicited through these signaling cascades. The particular cellular response regulated or inhibited will depend, in part, on the specific cell type and receptor signaling cascade, as is well known in the art. Non-limiting examples of cellular responses that may be regulated or inhibited with the 2,4-pyrimidiamine compounds include a respiratory burst, cellular adhesion, cellular degranulation, cell spreading, cell mi-gration, phagocytosis (e.g., in macrophages), calcium ionflux (e.g., in mast, basophil, neutrophil, eosinophil and B-cells), platelet aggregation, and cell maturation (e.g., in B-cells).

[0033] Thus, in another aspect, methods are described of regulating, and in particular inhibiting, signal transduction cascades in which Syk plays a role. The method generally involves contacting a Syk-dependent receptor or a cell expressing a Syk-dependent receptor with an amount of a 2,4-pyrimidinediannine compound or prodrug or an acceptable salt, hydrate, solvate, N-oxide and/or composition thereof, effective to regulate or inhibit the signal transduction cascade. The methods may also be used to regulate, and in particular inhibit, downstream processes or cellular responses elicited by activation of the particular Syk-dependent signal transduction cascade. The methods may be practiced to regulate any signal transduction cascade where Syk is not known or later discovered to play a role. The methods may be practiced in in vitro contexts or in in vivo contexts as a therapeutic approach towards the treatment or prevention of diseases characterized by, caused by or associated with activation of the Syk-dependent signal transduction cascade. Non-limited examples of such diseases include those previously discussed.

[0034] Cellular and animal data also confirm that the 2,4-pyrimidinediamine compounds may also be used to treat or prevent autoimmune diseases and/or symptoms of such diseases. The methods generally involve administering to a subject suffering from an autoimmune disease or at risk of developing an autoimmune disease an amount of a 2,4-pyrimidinediamine compound or prodrug, or an acceptable salt, N-oxide, hydrate, solvate or composition thereof, effective to treat or prevent the autoimmune disease and/or its associated symptoms. Autoimmune diseases that can be treated or prevented with the 2,4-pyrimidinediamine compounds include those diseases that are commonly associated witch nonanaphylactic hypersensitivity reactions (Type II, Type III and/or Type IV hypersensitivity reactions) and/or those diseases that are mediated, at least in part, by activation of the FcyR signaling cascade in monocyte cells. Such autoimmune disease include, but are not limited to, those autoimmune diseases that are frequently designated as single organ or single cell-type autoimmune disorders and those autoimmune disease that are frequently designated as involving systemic autoimmune disorder. Non-limiting examples of diseases frequently designated as single organ or single celltype autoimmune disorders include: Hashimoto's thyroiditis, autoimmune hemolytic anemia, autoimmune atrophic gastritis of pernicious anemia, autoimmune encephalomyelitis, autoimmune orchitis, Goodpasture’s disease, autoimmune thrombocytopenia, sympathetic ophthalmia, myasthenia gravis, Graves’ disease, primary biliary cirrhosis, chronic aggressive hepatitis, ulcerative colitis and membranous glomerulopathy. Non-limiting examples of diseases often designated as involving systemic autoimmune disorder include: systemic lupus erythematosis, rheumatoid arthritis, Sjogren’s syndrome, Reiter’s syndrome, polymyositis-dermatomyositis, systemic sclerosis, polyarteritis nodosa, multiple sclerosis and bullous pemphigoid.

5. BRIEF DESCRIPTION OF THE FIGURES [0035]

FIG. 1 provides a cartoon illustrating allergen-induced production of IgE and consequent release of preformed and other chemical mediators from mast cells;

FIG. 2 provides a cartoon illustrating the FceRI signal transduction cascade leading to degranulation of mast and/or basophil cells;

FIG. 3 provides a cartoon illustrating the putative points of action of compounds that selectively inhibit upstream FceRI-mediated degranulation and compounds that inhibit both FceRI-mediated and ionomycin-induced degranulation;

FIG. 4 provides graphs illustrating the effects of certain 2,4-pyrimidinediamine compounds, DMSO (control) and ionomycin on Ca²⁺ flux in CHMC cells;

FIG. 5 provides graphs illustrating the immediacy of the inhibitory activity of compounds R921218 and R926495; FIG. 6 provides a graph illustrating the effect of washout on the inhibitory activity of compounds R921218 and R921302;

FIG. 7 provides data showing that varying concentrations of compounds R921218 (A) and R921219 (B) inhibit phosporylation of various proteins downstream of Syk kinase in the IgE receptor signal transduction cascade in activated BMMC cells;

FIG. 8 provides data showing dose responsive inhibition of Syk kinase phosphorylation of an endogenous substrate (LAT) and a peptide substrate in the presence of increasing concentrations of compounds R921218 (X), R921219 (Y) and R921304 (Z);

FIG. 9 provides data showing that the inhibition of Syk kinase by compound R921219 is ATP competitive;

FIG. 10 provides data showing that varying concentrations of compounds R921219 (A) and R218218 (B) inhibit phosphorylation of proteins downstream of Syk kinase, but not LYN kinase, in the FceRI signal transduction cascade in activated CHMC cells; also shown is inhibition of phosphorylation of proteins downstream of LYN kinase but not Syk kinase, in the presence of a know LYN kinase inhibitor (PP2);

FIGS. 11A-D provide data showing inhibition of phosphorylation of proteins downstream of Syk kinase in the FœRI signal transduction cascade in BMMC cells;

FIG. 12 is a graph illustrating the efficacy of compound R921302 in a mouse model of collagen antibody-induced arthritis ("CAIA");

FIG. 13 is a graph illustrating the efficacy of compound R921302 in the CAIA model as compared to other agents and control agents;

FIG. 14 is a graph illustrating the efficacy of compound R921302 in a rat model of collagen-induced arthritis ("CIA"); FIG. 15 is a graph illustrating the Efficacy of compound R921302 in inhibiting experimental autoimmune encephalomyelitis ("EAE") in mice, a clinical model for multiple sclerosis; and

FIG. 16 is a graph illustrating the efficacy compound R921302 on S JL mice treated on the starting day of immunization with 150 μg PLP 139-151/200 μg MTB (CFA).

6. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

6.1 Definitions [0036] As used herein, the following terms are intended to have the following meanings:

"Alkyl" by itself or as part of another substituent refers to a saturated or unsaturated branched, straight-chain or cyclic monovalent hydrocarbon radical having the stated number of carbon atoms (/.e., C1-C6 means one to six carbon atoms) that is derived by the removal of one hydrogen atom from a single carbon atom of a parent alkane, alkene or alkyne. Typical alkyl groups include, but are not limited to, methyl; ethyls such as ethanyl, ethenyl, ethynyl; propyls such as propan-1-yl, propan-2-yl, cyclopropan-1-yl, prop-1-en-1-yl, prop-1-en-2-yl, prop-2-en-1-yl, cyclo-prop-1-en-l-yl; cycloprop-2-en-1-yl, prop-1-yn-1-yl, prop-2-yn-1-yl, etc.; butyls such as butan-1-yl, butan-2-yl, 2-methyl-propan-1-yl, 2-methyl-propan-2-yl, cyclobutan-1-yl, but-1-en-1-yl, but-1-en-2-yl, 2-methyl-prop-1-en-1-yl, but-2-en-1-yl, but-2-en-2-yl, buta-1,3-dien-1-yl, buta-1,3-dien-2-yl, cyclobut-1-en-1-yl, cyclobut-1-en-3-yl, cyclobu-ta-1,3-dien-1 -yl; but-1-yn-1-yl, but-1-yn-3-yl, but-3-yn-1-yl, etc.; and the like. Where specific levels of saturation are intended, the nomenclature "alkanyl," "alkenyl" and/or"alkynyl" is used, as defined below. In preferred embodiments, the alkyl groups are (C1-C6) alkyl.

"Alkanyl" by itself or as part of another substituent refers to a saturated branched, straight-chain or cyclic alkyl derived by the removal of one hydrogen atom from a single carbon atom of a parent alkane. Typical alkanyl groups include, but are not limited to, methanyl; ethanyl; propanyls such as propan-1 -yl, propan-2-yl (isopropyl), cyclopropan-1-yl, etc.; butanyls such as butan-1-yl, butan-2-yl (sec-butyl), 2-methyl-propan-1-yl (isobutyl), 2-methyl-propan-2-yl (t-butyl), cyclobutan-1-yl, etc.; and the like. In preferred embodiments, the alkanyl groups are (C1-C6) alkanyl. "Alkenyl" by itself or as part of another substituent refers to an unsaturated branched, straight-chain or cyclic alkyl having at least one carbon-carbon double bond derived by the removal of one hydrogen atom from a single carbon atom of a parent alkene. The group may be in eitherthe cis or trans conformation about the double bond(s). Typical alkenyl groups include, but are not limited to, ethenyl; propenyls such as prop-1-en-1-yl, prop-1-en-2-yl, prop-2-en-1-yl, prop-2-en-2-yl, cycloprop-1-en-1-yl; cycloprop-2-en-1-yl; butenyls such as but-1-en-1-yl, but-1-en-2-yl, 2-me-thyl-prop-1 -en-1 -yl, but-2-en-1-yl, but-2-en-2-yl, buta-1,3-dien-1 -yl, buta-1,3-dien-2-yl, cyclobut-1-en-1-yl, cyclobut-1 -en-3-yl, cyclobuta-1,3-dien-1-yl, etc.; and the like. In preferred embodiments, the alkenyl group is (C2-C6) alkenyl.

"Alkynyl" by itself or as part of another substituent refers to an unsaturated branched, straight-chain or cyclic alkyl having at least one carbon-carbon triple bond derived by the removal of one hydrogen atom from a single carbon atom of a parent alkyne. Typical alkynyl groups include, but are not limited to, ethynyl; propynyls such as prop-1-yn-1-yl ,prop-2-yn-1-yl,etc.;butynylssuchasbut-1-yn-1-yl,but-1-yn-3-yl,but-3-yn-1-yl,etc.;andthelike. Inpreferred embodiments, the alkynyl group is (C2-C6) alkynyl.

"Alkyldiyl" by itself or as part of another substituent refers to a saturated or unsaturated, branched, straight-chain or cyclic divalent hydrocarbon group having the stated number of carbon atoms (/.e., C1-C6 means from one to six carbon atoms) derived by the removal of one hydrogen atom from each of two different carbon atoms of a parent alkane, alkene or alkyne, or by the removal of two hydrogen atoms from a single carbon atom of a parent alkane, alkene or alkyne. The two monovalent radical centers or each valency of the divalent radical center can form bonds with the same or different atoms. Typical alkyldiyl groups include, but are not limited to, methandiyl; ethyldiyls such as ethan-1,1-diyl, ethan-1,2-diyl, ethen-1,1-diyl, ethen-1,2-diyl; propyldiyls such aspropan-1,1-diyl, propan-1,2-diyl, propan-2,2-diyl, propan-1,3-diyl, cyclopropan-1,1-diyl, cyclopropan-1,2-diyl, prop-1-en-1,1-diyl, prop-1-en-1,2-diyl, prop-2-en-1,2-diyl; prop-1 -en-1,3-diyl, cycloprop-1-en-1,2-diyl, cycloprop-2-en-1,2-diyl, cycloprop-2-en-1,1-diyl, prop-1 -yn-1,3-diyl, etc.; butyldiyls such as, butan-1,1-diyl, butan-1,2-diyl, butan-1,3-diyl, butan-1,4-diyl, butan-2,2-diyl, 2-methyl-propan-1,1-diyl, 2-methyl-propan-1,2-diyl, cyclobutan-1,1-diyl; cyclobutan-1,2-diyl, cyclobutan-1,3-diyl, but-1-en-1,1-diyl, but-1-en-1,2-diyl, but-1-en-1,3-diyl, but-1-en-1,4-diyl, 2-methyl-prop-1-en-1,1-diyl, 2-metha-nylidene-propan-1,1-diyl, buta-1,3-dien-1,1-diyl, buta-1,3-dien-1,2-diyl, buta-1,3-dien-1,3-diyl, buta-1,3-dien-1,4-di-yl, cyclobut-1-en-1,2-diyl, cyclobut-1-en-1,3-diyl, cyclobut-2-en-1,2-diyl, cyclobuta-1,3-dien-1,2-diyl, cyclobuta-1,3-dien-1,3-diyl, but-1-yn-1,3-diyl, but-1-yn-1,4diyl, buta-1,3-diyn-1,4-diyl, etc.; and the like. Where specific levels of saturation are intended, the nomenclature alkanyldiyl, alkenyldiyl and/or alkynyldiyl is used. Where it is specifically intended that the two valencies are on the same carbon atom, the nomenclature "alkylidene" is used. In preferred embodiments, the alkyldiyl group is (C1-C6) alkyldiyl. Also preferred are saturated acyclic alkanyldiyl groups in which the radical centers are at the terminal carbons, e.g., methandiyl (methano); ethan-1,2-diyl (ethano); propan-1,3-diyl (propano); butan-1,4-diyl (butano); and the like (also referred to as alkylenos, defined infra).

"Alkyleno" by itself or as part of another substituent refers to a straight-chain saturated or unsaturated alkyldiyl group having two terminal monovalent radical centers derived by the removal of one hydrogen atom from each of the two terminal carbon atoms of straight-chain parent alkane, alkene or alkyne. The locant of a double bond or triple bond, if present, in a particular alkyleno is indicated in square brackets. Typical alkyleno groups include, but are not limited to, methano; ethylenos such as ethano, etheno, ethyno; propylenos such as propano, prop[1]eno, propa[1,2]dieno, prop[1]yno, etc.; butylenos such as butano, but[1]eno, but[2]eno, buta[1,3]dieno, but[1]yno, but[2]yno, buta[1,3] diyno, etc.; and the like. Where specific levels of saturation are intended, the nomenclature alkano, alkeno and/or alkyno is used. In preferred embodiments, the alkyleno group is (C1-C6) or (C1-C3) alkyleno. Also preferred are straight-chain saturated alkano groups, e.g., methano, ethano, propano, butano, and the like.

"Heteroalkyl" Heteroalkanyl," Heteroalkenyl," Heteroalkynyl," Heteroalkyldiyl" and "Heteroalkyleno" by themselves or as part of another substituent refer to alkyl, alkanyl, alkenyl, alkynyl, alkyldiyl and alkyleno groups, respectively, in which one or more of the carbon atoms are each independently replaced with the same or different heteratoms or heteroatomic groups. Typical heteroatoms and/or heteroatomic groups which can replace the carbon atoms include, but are not limited to, -0-, -S-, -S-0-, -NR’-, -PH-, -S(0)-, -S(0)₂-, -S(0) NR'-, -S(O)₂NR’-, and the like, including combinations thereof, where each R’ is independently hydrogen or (C1-C6) alkyl.

"Cycloalkyl" and "Heterocycloalkyl" by themselves or as part of another substituent refer to cyclic versions of "alkyl" and "heteroalkyl" groups, respectively. For heteroalkyl groups, a heteroatom can occupy the position that is attached to the remainder of the molecule. Typical cycloalkyl groups include, but are not limited to, cyclopropyl; cyclobutyls such as cyclobutanyl and cyclobutenyl; cyclopentyls such as cyclopentanyl and cyclopentenyl; cyclohexyls such as cyclohexanyl and cyclohexenyl; and the like. Typical heterocycloalkyl groups include, but are not limited to, tetrahydrofuranyl (e.g., tetrahydrofuran-2-yl, tetrahydrofuran-3-yl, etc.), piperidinyl (e.g., piperidin-1 -yl, piperidin-2-yl, etc.), morpholinyl (e.g., morpholin-3-yl, morpholin-4-yl, etc.), piperazinyl (e.g., piperazin-1-yl, piperazin-2-yl, etc.), and the like.

"Acyclic Heteroatomic Bridge" refers to a divalent bridge in which the backbone atoms are exclusively heteroatoms and/or heteroatomic groups. Typical acyclic heteroatomic bridges include, but are not limited to, -0-, -S-, -S-0-, -NR’-, -PH-, -S(0)-, -S(0)₂-, -S(0) NR’-, -S(O)₂NR’-, and the like, including combinations thereof, where each R’ is independently hydrogen or (C1-C6) alkyl.

"Parent Aromatic Ring System" refers to an unsaturated cyclic or polycyclic ring system having a conjugated π electron system. Specifically included within the definition of "parent aromatic ring system" are fused ring systems in which one or more of the rings are aromatic and one or more of the rings are saturated or unsaturated, such as, forexample, fluorene, indane, indene, phenalene, tetrahydronaphthalene, etc. Typical parent aromatic ring systems include, but are not limited to, aceanthrylene, acenaphthylene, acephenanthrylene, anthracene, azulene, benzene, chrysene, coronene, fluoranthene, fluorene, hexacene, hexaphene, hexalene, indacene, s-indacene, indane, indene, naphthalene, octacene, octaphene, octalene, ovalene, penta-2,4-diene, pentacene, pentalene, pentaphene, peryl-ene, phenalene, phenanthrene, picene, pleiadene, pyrene, pyranthrene, rubicene, tetrahydronaphthalene, triphe-nylene, trinaphthalene, and the like, as well as the various hydro isomers thereof.

"Aryl" by itself or as part of another substituent refers to a monovalent aromatic hydrocarbon group having the stated number of carbon atoms (i.e., CS-C15 means from 5 to 15 carbon atoms) derived by the removal of one hydrogen atom from a single carbon atom of a parent aromatic ring system. Typical aryl groups include, but are not limited to, groups derived from aœanthrylene, acenaphthylene, acephenanthrylene, anthracene, azulene, benzene, chrysene, coronene, fluoranthene, fluorene, hexacene, hexaphene, hexalene, as-indacene, s-indacene, indane, indene, naphthalene, octacene, octaphene, octalene, ovalene, penta-2,4-diene, pentacene, pentalene, pentaphene, perylene, phenalene, phenanthrene, picene, pleiadene, pyrene, pyranthrene, rubicene, triphenylene, trinaphthalene, and the like, as well as the various hydro isomers thereof. In preferred embodiments, íhe aryl group is (CS-C15) aryl, with (CS-C10) being even more preferred. Particularly preferred arylsarecyclopentadienyl, phenyl and naphthyl. "Arylaryl" by itself or as part of another substituent refers to a monovalent hydrocarbon group derived by the removal of one hydrogen atom from a single carbon atom of a ring system in which two or more identical or non-identical parent aromatic ring systems are joined directly together by a single bond, where the number of such direct ring junctions is one less than the number of parent aromatic ring systems involved. Typical arylaryl groups include, but are not limited to, biphenyl, triphenyl, phenyl-naphthyl, binaphthyl, biphenyl-naphthyl, and the like. Where the number of carbon atoms in an arylaryl group are specified, the numbers refer to the carbon atoms comprising each parent aromatic ring. For example, (CS-C15) arylaryI is an arylaryI group in which each aromatic ring comprises from 5 to 15 carbons, e.g., biphenyl, triphenyl, binaphthyl, phenylnaphthyl, etc. Preferably, each parent aromatic ring system of an arylaryl group is independently a (CS-C15) aromatic, more preferably a (CS-C10) aromatic. Also preferred are arylaryl groups in which all ofthe parent aromatic ring systems areidentical, e.g., biphenyl, triphenyl, binaphthyl, trinaphthyl, etc.

"Biaryl" by itself or as part of another substituent refers to an arylaryl group having two identical parent aromatic systems joined directly together by a single bond. Typical biaryl groups include, but are not limited to, biphenyl, binaphthyl, bianthracyl, and the like. Preferably, the aromatic ring systems are (C5-C15) aromatic rings, more preferably (CS-C10) aromatic rings. A particularly preferred biaryl group is biphenyl.

"Arylalkyl" by itself or as part of another substituent refers to an acyclic alkyl group in which one of the hydrogen atoms bonded to a carbon atom, typically a terminal or sp³ carbon atom, is replaced with an aryl group. Typical arylalkyl groups include, but are not limited to, benzyl, 2-phenylethan-1-y1,2-phenyíethen-1-y1, naphthylmethyl, 2-naphthylethan-1-y 1,2-naphthylethen-1 -y1, naphthobenzyl, 2-naphthophenylethan-1 -y1 and the Iike. Where specific alkyl moieties are intended, the nomenclature arylalkanyl, arylakenyl and/or arylalkynyl is used. In preferred em-bodiments, the arylalkyl group is (C6-C21) arylalkyl, e.g., the alkanyl, alkenyl oralkynyl moiety of the arylalkyl group is (C1-C6) and the aryl moiety is (C5-C15). In particularly preferred embodiments the arylalkyl group is (C6-C13), e.g., the alkanyl, alkenyl or alkynyl moiety of the arylalkyl group is (C1-C3) and the aryl moiety is (C5-C10).

"Parent Heteroaromatic Ring System" refers to a parent aromatic ring system in which, one or more carbon atoms are each independently replaced with the same or different heteroatoms or heteroatomicgroups. Typical heteroatoms or heteroatomic groups to replace the carbon atoms include, but are not limited to, N, NH, P, O, S, S(O), S(O)₂, Si, etc. Specifically included within the definition of "parent heteroaromatic ring systems" are fused ring systems in which one or more of the rings are aromatic and one or more of the rings are saturated or unsaturated, such as, for example, benzodioxan, benzofuran, chromane, chromene, indole, indoline, xanthene, etc. Also included in the definition of "parent heteroaromatic ring system" are those recognized rings that include common substituents, such as, for example, benzopyrone and 1-methyl-1,2,3,4-tetrazole. Specifically excluded from the definition of "parent heteroaromatic ring system" are benzene rings fused to cyclic polyalkylene glycols such as cyclic polyethylene glycols. Typical parent heteroaromatic ring systems include, but are not limited to, acridine, benzimidazole, ben-zisoxazole, benzodioxan, benzodioxole, benzofuran, benzopyrone, benzothiadiazole, benzothiazole, benzotriazole, benzoxaxine, benzoxazole, benzoxazoline, carbazole, β-carboline, chromane, chromene, cinnoline, furan, imida-zole, indazole, indole, indoiine, indolizine, isobenzofuran, isochromene, isoindole, isoindoline, isoquinoline, isothi-azole, isoxazole, naphthyridine, oxadiazole, oxazole, perimidine, phenanthridine, phenanthroline, phenazine, phthalazine, pteridine, purine, pyran, pyrazine, pyrazole, pyrídazine, pyridine, pyrimidine, pyrrole, pyrrolizine, quina-zoline, quinoline, quinolizine, quinoxaline, tetrazole, thiadiazole, thiazole, thiophene, triazole, xanthene, and the like. "Heteroaryl" by itself or as part of another substituent refers to a monovalent heteroaromatic group having the stated numberof ring atoms (e.g., "5-14 membered" meansfrom 5to 14 ring atoms) derived by the removal of one hydrogen atom from a single atom of a parent heteroaromatic ring system. Typical heteroaryl groups include, but are not limited to, groups derived from acridine, benzimidazole, benzisoxazole, benzodioxan, benzodiaxole, benzofuran, benzopyrone, benzothiadiazole, benzothiazole, benzotriazole, benzoxazine, benzoxazole, benzoxazoline, carba-zole, β-carboline, chromane, chromene, cinnoline, furan, imidazole, indazole, indole, indoline, indolizine, isobenzo-furan, isochromene, isoindole, isoindoline, isoquinoline, isothiazole, isoxazole, naphthyridine, oxadiazole, oxazole, perimidine, phenanthridine, phenanthroline, phenazine, phthalazine, pteridine, purine, pyran, pyrazine, pyrazole, pyridazine, pyridine, pyrimidine, pyrrole, pyrrolizine, quinazoline, quinoline, quinolizine, quinoxaline, tetrazole, thia-diazole, thiazole, thiophene, triazole, xanthene, and the like, as well as the various hydro isomers thereof. In preferred embodiments, the heteroaryl group is a 5-14 membered heteroaryl, with 5-10 membered heteroaryl being particularly preferred.

"Heteroaryl-Heteroaryl" by itself or as part of another substituent refers to a monovalent heteroaromatic group derived by the removal of one hydrogen atom from a single atom of a ring system in which two or more identical or non-identical parent heteroaromatic ring systems are joined directly together by a single bond, where the number of such direct ring junctions is one less than the number of parent heteroaromatic ring systems involved. Typical heteroaryl-heteroaryl groups include, but are not limited to, bipyridyl, tripyridyl, pyridylpurinyl, bipurinyl, etc. Where the numberof atoms are specified, the numbers referto the numberof atoms comprising each parent heteroaromatic ring systems. For example, 5-15 membered heteroaryl-heteroaryl is a heteroaryl-heteroaryl group in which each parent heteroaromatic ring system comprises from 5 to 15 atoms, e.g., bipyridyl, tripuridyl, etc. Preferably, each parent heteroaromatic ring system is independently a 5-15 membered heteroaromatic, more preferably a 5-10 membered heteroaromatic. Also preferred are heteroaryl-heteroaryl groups in which all of the parent heteroaromatic ring systems are identical.

"Biheteroaryl" by itself or as part of another substituent refers to a heteroaryl-heteroaryl group having two identical parent heteroaromatic ring systems joined directly together by a single bond. Typical biheteroaryl groups include, but are not limited to, bipyridyl, bipurinyl, biquinolinyl, and the like. Preferably, the heteroaromatic ring systems are

5-15 membered heteroaromatic rings, more preferably 5-10 membered heteroaromatic rings.

"Heteroarylalkyl" by itself or as part of another substituent refers to an acyclic alkyl group in which one of the hydrogen atoms bonded to a carbon atom, typically a terminal or sp³ carbon atom, is replaced with a heteroaryl group. Where specific alkyl moieties are intended, the nomenclature heteroarylalkanyl, heteroarylakenyl and/or heteroarylalkynyl is used. In preferred embodiments, the heteroarylalkyl group is a 6-21 membered heteroarylalkyl, e.g., the alkanyl, alkenyl or alkynyl moiety of the heteroarylalkyl is (C1-C6) alkyl and the heteroaryl moiety is a 5-15-membered heteroaryl. In particularly preferred embodiments, the heteroarylalkyl is a 6-13 membered heteroarylalkyl, e.g., the alkanyl, alkenyl or alkynyl moiety is (C1-C3) alkyl and the heteroaryl moiety is a 5-10 membered heteroaryl.

"Haloqen" or "Halo" by themselves or as part of another substituent, unless otherwise stated, refer to fluoro, chloro, bromo and iodo.

"Haloalkyl" by itself or as part of another substituent refers to an alkyl group in which one or more of the hydrogen atoms is replaced with a halogen. Thus, the term "haloalkyl" is meant to include monohaloalkyls, dihaloalkyls, trihaloalkyls, etc. up to perhaloalkyls. For example, the expression "(C1-C2) haloalkyl" includes fluoromethyl, dif-luoromethyl, trifluoromethyl, 1 -fluoroethyl, 1,1-difluoroethyl, 1,2-difluoroethyl, 1,1,1-trifluoroethyl, perfluoroethyl, etc.

[0037] The above-defined groups may include prefixes and/or suffixes that are commonly used in the art to create additional well-recognized substituent groiips. As examples, "alkyloxy" or "alkoxy" refers to a group of the formula -OR", "alkylamine" refers to a group of the formula -NHR" and "dialkylamine" refers to a group of the formula -NR"R", where each R" is independently an alkyl. As another example, "haloalkoxy" or "haloalkyloxy" refers to a group of the formula -OR'”, where R’" is a haloalkyl.

[0038] "Protecting qroup" refers to a group of atoms that, when attached to a reactive functional group in a molecule, mask, reduce or prevent the reactivity of the functíonal group. Typically, a protecting group may be selectiveíy removed as desired during the course of a synthesis. Examples of protecting groups can be found in Greene and Wuts, Protective Groups in Organic Chemistry, 3rd Ed., 1999, John Wiley &amp; Sons, NY and Harrison et al., Compendium of Synthetic Organic Methods, Vols. 1-8, 1971-1996, John Wiley &amp; Sons, NY. Representative amino protecting groups include, but are not limited to, formyl, acetyl, trifluoroacetyl, benzyl, benzyloxycarbonyl ("CBZ"), tert-butoxycarbonyl ("Boc"), trimethylsilyl ("TMS"), 2-trimethylsilyl-ethanesulfonyl ("’TES"), trityl and substituted trityl groups, allyloxycarbonyl, 94luorenyl-methyloxycarbonyl ("FMOC"), nitroveratryloxycarbonyl ("NVOC") and the like. Representative hydroxyl protecting groups include, but are not limited to, those where the hydroxyl group is either acylated or alkylated such as benzyl and trityl ethers, as well as alkyl ethers, tetrahydropyranyl ethers, trialkylsilyl ethers (e.g., TMS or TIPPS groups) and allyl ethers. [0039] "Prodrug" refers to a derivative of an active 2,4-pyrimidinediamine compound (drug) that requires a transformation under the conditions of use, such as within the body, to release the active 2,4-pyrimidinediamine drug. Prodrugs are frequently, but not necessarily, pharmacologically inactive until converted into the active drug. Prodrugs are typically obtained by masking a functional group in the 2,4-pyrimidinediamine drug believed to be in part required for activity with a progroup (defined below) to form a promoiety which undergoes a transformation, such as cleavage, under the specified conditions of use to release the functional group, and hence the active 2,4-pyrimidinediamine drug. The cleavage of the promoiety may proceed spontaneously, such as by way of a hydrolysis reaction, or it may be catalyzed or induced by another agent, such as by an enzyme, by light, by acid or base, or by a change of or exposure to a physical or environmental parameter, such as a change of temperature. The agent may be endogenous to the conditions of use, such as an enzyme present in the cells to which the prodrug is administered or the acidic conditions of the stomach, or it may be supplied exogenously.

[0040] A wide variety of progroups, as well as the resultant promoieties, suitable for masking functional groups in the active 2,4-pyrimidinediamines compounds to yield prodrugs are well-known in the art. For example, a hydroxyl functional group may be masked as a sulfonate, ester or carbonate promoiety, which may be hydrolyzed in vivo to provide the hydroxylgroup. Anaminofunctionalgroupmay be masked asanamide.carbamate, imine, urea, phosphenyl, phosphoryl or sulfenyl promoiety, which may be hydrolyzed in vivo to provide the amino group. A carboxyl group may be masked as an ester (including silyl esters and thioesters), amide or hydrazide promoiety, which may be hydrolyzed /n vivo to provide the carboxyl group. Other specific examples of suitable progroups and their respective promoieties will be apparent to those of skill in the art.

[0041 ] "Progroup" refers to a type of protecting group that, when used to mask a functional group within an active 2,4-pyrimidinediamine drug to form a promoiety, converts the drug into a prodrug. Progroups are typically attached to the functional group of the drug via bonds that are cleavable under specified conditions of use. Thus, a progroup is that portion of a promoiety that cleaves to release the functional group under the specified conditions of use. As a specific example, an amide promoiety of the formula -NH-C(O)CH₃ comprises the progroup -C(O)CH₃.

[0042] "Fc Receptor" refers to a member of the family of celI surface molecules that binds the Fc portion (containing the specific constant region) of an immunoglobulin. Each Fc receptor binds immunoglobulins of a specific type. For example the Fca receptor ("FcaR") binds IgA, the FceR binds IgE and the FcyR binds IgG.

[0043] The FcaR family includes the polymeric Ig receptor involved in epithelial transport of IgA/lgM, the mycloid specific receptor RcotRI (also called CD89), the Fcœ^R and at least two alternative IgA receptors (for a recent review see Monteiro &amp; van de Winkel, 2003, Annu. Rev. Immunol, advanced e-publication. The FcaRI is expressed on neu-trophils, eosinophils, moncytes/macrophages, dendritic cells and kupfer cells. The FcaRI inclues one alpha chain and the FcR gamma homodimer that bears an activation motif (ITAM) in the cytoplasmic domain and phosphorylates Syk kinase.

[0044] The FceR family includes two types, designated FceRI and FceRII (also known as CD23). FceRI is a high affinity receptor (binds IgE with an affinity of about 10¹ °M’¹) found on mast, basophil and eosinophil cells that anchors monomeric IgE to the cell surface. The FœRI possesses one alpha chain, one beta chain and the gamma chain homodimer discussed above. The FœRII is a low affinity receptor expressed on mononuclear phagocytes, B lymphocytes, eosinophils and platelets. The FœRII comprises a single polypeptide chain and does not include the gamma chain homodimer.

[0045] The FcyR family includes three types, designated FcrfljbRI (also known as CD64), FcyRII (also known as CD32) and FcyRIII (also known as CD16). FcyRI is a high affinity receptor (binds lgG1 with an affinity of 10⁸M^_1)found on mast, basophil, mononuclear, neutrophil, eosinophil, deudritic and phagocyte cells that anchors nomomeric IgG to the cell surface. The FcyRI includes one alpha chain and the gamma chain dimer shared by FcaRI and FceRI.

[0046] The FcyRII is a low affinity receptor expressed on neutrophils, monocytes, eosinophils, platelets and B lymphocytes. The FcyRII includes one alpha chain, and does not include the gamma chain homodimer discussed above. [0047] TheFcyRIII isalowaffinity (bindes lgG1 withanaffinityof5x10⁵M’¹)expressedon NK, eosinophil, macrophage, neutrophil and mast cells. It comprises one alpha chain and the gamma homodimer shared by FcaRI, FCeRI and FcyRI. [0048] Skilled artisans will recognize that the subunit structure and binding properties of tbese various Fc receptors, cell types expressing them, are not completely characterized. The above discussion merely reflects the current state-of-the-art regarding these receptors (see, e.g., Immunobiology: The Immune System in Health &amp; Disease, 5th Edition, Janeway et al., Eds, 2001, ISBN 0-8153-3642-x, Figure 9.30 at pp. 371), and is not intended to be limiting with respect to the myriad receptor signaling cascades that can be regulated with the compounds described herein.

[0049] "Fc Receptor-Mediated Degranulation" or "Fc Receptor-lnduced Degranulation" refers to degranulation that proceeds via an Fc receptor signal transduction cascade initiated by crosslinking of an Fc receptor.

[0050] "IgE-lnduced Degranulation" or "FceRI-Mediated Degranulation" refers to degranulation that proceeds via the IgE receptor signal transduction cascade initiated by crosslinking of FceR1 -bound IgE. The crosslinking may be induced by an IgE-specific allergen orother multivalent binding agent, such as an anti-lgE antibody. Referring to FIG. 2, in mast and/or basophil cells, the FceRI signaling cascade leading to degranulation may be broken into two stages: upstream and downstream. The upstream stage includes all of the processes that occur prior to calcium ion mobilization (illustrated as "Ca²⁺" in FIG. 2; see also FIG. 3). The downstream stage includes calcium ion mobilization and all processes downstream thereof. Compounds that inhibit FcERI-mediated degranulation may act at any point along the FœRI-me-diated signal transduction cascade. Compounds that selectively inhibit upstream FceRI-mediated degranulation act to inhibit that portion of the FœRI signaling cascade upstream of the point at which calcium ion mobilization is induced. In cell-based assays, compounds that selectively inhibit upstream FœRI-mediated degranulation inhibit degranulation of cells such as mast or basophil cells tbat are activated or stimulated with an IgE-specific allergen or binding agent (such as an anti-lgE antibody) but do not appreciably inhibit degranulation of cells that are activated or stimulated with degranulating agents that bypass the FœRI signaling pathway, such as, for example the calcium ionophores ionomycin and A23187.

[0051 ] "IgG-lnduced Degranulation" or "FcyRI-Mediated Degranulation" refers to degranulation that proceeds viathe FcyRI signal transduction cascade initiated by crosslinking of FcyRI-bound IgG. The crosslinking may be induced by an IgG-specific allergen or another multivalent binding agent, such as an anti-lgG or fragment antibody. Like the FœRI signaling cascade, in mast and basophil cells the FcyRI signaling cascade also leads to degranulation which may be broken into the same two stages: upstream and downstream. Similar to FœRI-mediated degranulation, compounds that selectively inhibit upstream FcyRI-mediated degranulation act upstream of the point at which calcium ion mobilization is induœd. In cell-based assays, compounds that selectively inhibit upstream FcyRI-mediated degranulation inhibit degranulation of cells such as mast or basophil cells that are activated or stimulated with an IgG-specific allergen or binding agent (such as an anti-lgG antibody or fragment) but do not appreciably inhibit degranulation of ceils that are activated or stimulated with degranulating agents that bypass the FcyRI signaling pathway, such as, for example the calcium ionophores ionomycin and A23187.

[0052] "lonophore-lnduced Degranulation" or "lonophore-Mediated Degranulation" refers to degranulation of a cell, such as a mast or basophil cell, that occurs upon exposure to a calcium ionophore such as, for example, ionomycin or A23187.

[0053] "Syk Kinsase" refers to the well-known 72kDa non-receptor (cytoplasmic) spleen protein tyrosine kinase expressed in B-cells and other hematopoetic cells. Syk kinase includes two consensus Src-homology 2 (SH2) domains in tandem that bind to phosphorylated immunoreceptor tyrosine-based activation motifs ("ITAMs"), a "linker" domain and a catalytic domain (for a review of the structure and function of Syk kinase see Sada et al., 2001, J. Biochem. (Tokyo) 130:177-186); see also Turner et al., 2000, Immunology Today 21:148-154). Syk kinase has been extensively studied as an effector of B-cell receptor (BCR) signaling (Turner eí al., 2000, supra). Syk kinase is also critical for tyrosine phosphorylation of multiple proteins which regulate important pathways leading from immunoreceptors, such as Ca²⁺mobilization and mitogen-activated protein kinase (MAPK) cascades (see, e.g., FIG. 2) and degranulation. Syk kinase also plays a critical role in integrin signaling in neutrophils (see, e.g., Mocsai et al. 2002, Immunity 16:547-558).

[0054] As used herein, Syk kinase includes kinases from any species of animal, including but not limited to, homosa-piens, simian, bovine, porcine, rodent, etc., recognized as belonging tothe Sykfamily. Specifically included are isoforms, splice variants, allelic variants, mutants, both naturally occuring and man-made. The amino acid sequences of such Syk kinases are well known and available from GENBANK. Specific examples of mRNAs encoding different isoforms of human Syk kinase can be found at GENBANK accession no. gi|21361552|reflNM_003177.2|, gi|496899|emb|Z29630.1 |HSSYKPTK[496899] and gi| 15030258|gb|BC011399.1 |BC011399[15030258], which are incorporated herein by reference.

[0055] Skilled artisans will appreciate that tyrosine kinases belonging to other families may have active sites or binding pockets that are similar in three-dimensional structure to that of Syk. As a consequence of this structural similarity, such kinases, referred to herein as "Syk mimics," are expected to catalyze phosphorylation of substrates phosphorylated by Syk. Thus, it will be appreciated that such Syk mimics, signal transduction cascades in which such Syk mimics play a role and biological responses effected by such Syk mimics and Syk mimic-dependent signaling cascades may be regulated, and in particular inhibited, with the 2,4-pyrimidinediamine compounds described herein.

[0056] "Syk-Dependent Signaling Cascade" refers to a signal transduction cascade in which Syk kinase plays a role. Non-limiting examples of such Syk-dependent signaling cascades include the FcaRI, FœRI, FcyRI, FctRIII, BCR and integrin signaling cascades.

[0057] "Autoimmiine Disease" refers to those diseases which are commonly associated with the nonanaphylactic hypersensitivity reactions (Type II, Type III and/or Type IV hypersensitivity reactions) that generally result as a consequence of the subject’s own humoral and/or cell-mediated immune response to one or more immunogenic substances of endogenous and/or exogenous origin. Such autoimmune diseases are distinguished from diseases associated with the anaphylactic (Type I or IgE-mediated) hypersensitivity reactions.

6.2 The 2,4-Pyrimidinediamine Compounds [0058] The compounds used in The invention are generally 2,4-pyrimidinediamine compounds according to structural formula (I): <img file="IS2923B_D0022.tif" />

<img file="IS2923B_D0023.tif" />

including salts, hydrates, solvates and N-oxides thereof, wherein:

L¹ and L² are each, a direct bond;

R² is selected from the group consisting of phenyl mono substituted at the 3- or 5- position with an R⁸ group, phenyl di- or tri-substituted with one or more of the same or different R⁸ groups and an optionally substituted heteroaryl as defined below;

R⁴ is selected from the group consisting of phenyl substituted with one or more of the same or different R⁸ groups and an optionally substituted heteroaryl as defined below;

wherein, for R² and R⁴, each of said optionally substituted heteroaryl, independent of one another, is selected from the group consisting of: <img file="IS2923B_D0024.tif" />

<img file="IS2923B_D0025.tif" />

<img file="IS2923B_D0026.tif" />

<img file="IS2923B_D0027.tif" /> wherein:

p is an integerfrom one to three;

each — independently represents a single bond or a double bond;

R³⁵ is hydrogen or R⁸;

X is selected from the group consisting of CH, N and N-O;

each Y is independently selected from the group consisting of 0, S and NH;

each Y¹ is independently selected from the group consisting of O, S, SO, S0₂, SONR³⁶, NH and NR³⁷;

each Y² is independently selected from the group consisting of CH, CH₂, 0, S, N, NH and NR³⁷;

R³⁶ is hydrogen or alkyl;

R³⁷ is selected from the group consisting of hydrogen and a progroup selected from the group consisting of aryl, arylalkyl, heteroaryl, R^a, R^b, -CR^aR^b-0-C(0)R⁸, -CR^aR^b-O-PO(OR⁸)2, -CH2-O-PO(OR⁸)2, -CH₂-PO(OR⁸)2, -C (O)-CR^aR^b-N(CH3)₂, -CR^aR^b-O-C(O)-CR^aR^b-N(CH3)2, -C(O)R⁸, -C(0)CF3 and -C(O)-NR⁸-C(O)R⁸;

R³⁸ is selected from the group consisting of alkyl and aryl;

A is selected from the group consisting of Ο, NH and NR³⁸;

R⁹, R¹⁰, R¹¹ and R¹² are each, independently of one another, selected from the group consisting of alkyl, alkoxy, halogen, haloalkoxy, aminoalkyl and hydroxyalkyl, or, alternatively, R⁹and R¹⁰and/orR¹¹ and R¹² are taken together to form a ketal;

each Z is selected from the group consisting of hydroxyl, alkoxy, aryloxy, ester, and carbamate;

Q is selected from the group consisting of -OH, -OR⁸, -NR^CR^C, -NR³⁹-CHR^4o-R^b, -NR³⁹-(CH₂)_m-R^b and -NR³⁹-C (O)-CHR⁴⁰-NR^cR^c;

R³⁹ and R⁴⁰ are each, independently of one another, selected from the group consisting of hydrogen, alkyl, aryl, alkylaryl, arylalkyl and NHR⁸;

R⁵ is selected from the group consisting of-CN, -NC, , fluoro, (C1-C3) haloalkyl, (C1-C3) perhaloalkyl, (C1-C3) haloalkoxy, (C1-C3) perhaloalkoxy, -C(0)R^a, -C(0)0R^a, -C(O)CF₃ and -C(O)OCF₃;

R⁶ is hydrogen;

R⁸ is selected from the group consisting of R^e, R^b, R^e substituted with one or more of the same or different R^a or R^b, -0R^a substituted with one or more of the same or different R^a or R^b, -B(OR^a)2, -B(NR^CR^C)2, -(CH₂)_m-R^b, -(CHR^a)m-R^b, -0-(CH2)_m-R^b, -S-(CH2)m-R^b, -0-CHR^aR^b -0-CR^a(R^b)2, -0-(CHR^a)m-R^b, -O-(CH2)_m-CH[(CH₂)_m-R^b] R^b, -S-(CHR^a)m-R^b, -C(0)NH-(CH2)_m-R^b, -C(0)NH-(CHR^a)m-R^b, -O-(CH2)_m-C(O)NH-(CH₂)_m-R^b, -S-(CH2)m-C(O) NH-(CH2)m-R^b, -0-(CHR^a)m-C(0)NH-(CHR^a)m-R^b, -S-(CHR^a)m C(0)NH-(CHR^a)m-R^b, -NH-(CH2)_m-R^b, -NH-(CHR^a)m-R^b, -N[(CH2)_mR^b]2, -NH-C(O)-NH-(CH₂)_m-R^b, -NH-C(O)-(CH2)m-CHR^bR^b and -NH-(CH2)_m-C (0)-NH-(CH₂)_m-R^b;

each R^a is independently selected from the group consisting of hydrogen, (C1-C6) alkyl, (C3-C8) cycloalkyl, (C4011) cycloalkylalkyl, (C5-C10) aryl, (C6-C16) arylalkyl, 2-6 membered heteroalkyl, 3-8 membered cycloheteroalkyl, 4-11 membered cycloheteroalkylalkyl, 5-10 membered heteroaryl and 6-16 membered heteroarylalkyl;

each R^b is a suitable group independently selected from the group consisting of =0, -0R^d, (C1-C3) haloalkyloxy, =S, -SR^d, =NR^d, =N0R^d, -NR^CR^C, halogen, -CF3, -CN, -NC, -OCN, -SCN, -NO, -N02, =N2, -N3, -S(O)R^d, -S(0)2R^d, -S(0)20R^d, -S(O)NR^CR^C, -S(0)2NR^cR^c, -0S(0)R^d, -0S(0)2R^d, -0S(0)20R^d, -0S(0)₂NR^cR^c, -C(0)R^d, -C(0)0R^d,

<img file="IS2923B_D0028.tif" />

-C(O)NR^CR^C, -C(NH)NR^CR^C, -C(NR^a)NR^cR^c, -C(NOH)R^a, -C(NOH)NR^CR^C, -OC(O)R^d, -OC(O)OR^d, -OC(O)NR^CR^C, -OC(NH)NR^CR^C, -OC(NR^a)NR^cR^c, -[NHC(O)]nR^d, -[NR^aC(O)]nR^d, -[NHC(O)]nOR^d, -[NR^aC(O)]nOR^d, -[NHC (O)]„NR^CR^C, -[NR^aC(O)]nNR^cR^G, -[NHC(NH)]nNR^cR^c and -[NR^aC(NR^a)]_nNR^cR^c;

each R^c is independently R^a, or, alternatively, two R^c are taken together with the nitrogen atom to which they are bonded to form a 5 to 8-membered cycloheteroalkyl or heteroaryl which may optionally include one or more of the same or different additional heteroatoms and which may optionally be substituted with one or more of the same or different R^a or suitable R^b groups;

each R^d is independently an R^a;

each R^e is independently selected from the group consisting of (C1-C6) alkyl, (C3-C8) cycloalkyl,-(C4-C11) cy-cloalkylalkyl, (C5-C10) aryl, (C6-C16) arylalkyl, 2-6 membered heteroalkyl, 3-8 membered cycloheteroalkyl, 4-11 membered cycloheteroalkylalkyl, 5-10 membered heteroaryl and 6-16 membered heteroarylalkyl;

each m is independently an integer from 1 to 3; and each n is independently an integer from 0 to 3;

or the 2,4-pyrimidinediamine compound is a compound selected from the group consisting of 7.4.214 through 7.4.244, 7.4.250 through 7.4.252,7.4.256 through 7.4.258,7.4.262 through 7.4.269,7.4.272 through 7.4.276,7.4.278 through 7.4.280, 7.4.283 through 7.4.289, 7.4.296, 7.4.298 through 7.4.302, 7.4.304, 7.4.305, 7.4.308 through 7.4.313, 7.4.315, 7.4.317, and 7.4.318;

with the provisos that in formula (I):

(1) when R² is a substituted phenyl, then R⁵ is other than cyano or -C(O)NHR, where R is hydrogen or (C1-C6) alkyl;

(2) when R² and R⁴ are each independently a substituted or unsubstituted indole, then the R² and R⁴ are attached to the remainder of the molecule via a ring carbon atom; and (3) the compound is not <img file="IS2923B_D0029.tif" /> [0059] L¹ and L² are each a direct bond such that the 2,4-pyrimidinediamine compounds used in The invention are compounds according to structural formula (la):

<img file="IS2923B_D0030.tif" /> including salts, hydrates, soJvates and N-oxides thereof, wherein R², R⁴, R⁵ and R⁶ are as previously defined for structural formula (I). Additional specific embodiments of the 2,4-pyrimidinediamine compounds of The invention are described below.

[0060] In a first embodiment of the compounds of structural formulae (I) and (la), R², R⁴, R⁵, R⁶, L¹ and L² are as previously defined fortheir respective structures (I) and (la), with the proviso that R² is not 3,4,5-trimethoxyphenyl, 3,4,5-tri (C1-C6) alkoxyphenyl or

<img file="IS2923B_D0031.tif" />

<img file="IS2923B_D0032.tif" />

<img file="IS2923B_D0033.tif" /> where R²¹, R²² and R²³ are as defined for R¹, R² and R³, respectively of U.S. Patent No. 6,235,746. In a specific embodimentofthisfristembodiment, R²¹ ishydrogen,halo,straight-chainorbranched(C1-C6)alkyloptionallysubstituted with one or more of the same or different R²⁵ groups, hydroxyl, (C1-C6) alkoxy optionally substituted with one or more of the same or different phenyl or R²⁵ groups, thiol (-SH), (C1-C6) alkylthio optionally substituted with one or more of the same or different phenyl or R²⁵ groups, amino (-NH₂), -NHR²⁶ or-NR²⁶R²⁶; R²² and R²³ are each, independently of one another, a (C1-C6) straight-chain or branched alkyl optionally substituted with one or more of the same or different R²⁵ groups; R²⁵ is selected from the group consisting of halo, hydroxyl, (C1-C6) aJkoxy, thiol, (C1-C6) alkylthio, (C1 -C6) alkylamino and (C1-C6) dialkylamino; and each R²⁶ is independently a (C1-C6) alkyl optionally substituted with one or more of the same or different phenyl or R²⁵ groups or a -C(O)R²⁷, where R²⁷ is a (C1-C6) alkyl optionally substituted with one or more of the same or different phenyl or R²⁵ groups.

[0061 ] In another specific embodiment of this first embodiment, R²¹ is methoxy optionally substituted with one or more of the same or different halo groups and/or R²² and R²³ are each, independently of one another, a methyl or ethyl optionally substituted with one or more of the same or different halo groups.

[0062] In a second embodiment of the compounds of structural formulae (I) and (I a), R², R⁴, R⁵ and L² are as previously described for their respective structures (I) and (la), L¹ is a direct bond and R⁶ is hydrogen, with the proviso that R² is not 3,4,5-trimethoxyphenyl, 3,4,5-tri (C1-C6) alkoxyphenyl or <img file="IS2923B_D0034.tif" /> where R²¹, R²² and R²³ are as defined above, in connection with the first embodiment.

[0063] In a third embodiment, the 2,4-pyrimidinediamine compounds of structural formulae (I) and (la) exclude one or more of the following compounds:

N2,N4-bis(3-methylphenyl)-5-fluoro-2,4-pyrimidinediamine (R092788); N2,N4-bis(3-chlorophenyl)-5-fluoro-2,4-pyrimidinediamine (R067962); N2,N4-bis(2,5-dimethylphenyl)-5-fluoro-2,4-pyrimidinediamine (R067963); N2,N4-bis(3,4-dimethylphenyl)-5-fluoro-2,4-pyrimidinediamine (R067964); N2,N4-bis(2,4-dimethylphenyl)-5-fluoro-2,4-pyrimidinediamine (R070791); N2,N4-bis(3-bromophenyl)-5-fluoro-2,4-pyrimidinediamine (R008958); N2,N4-bis(morpholino)-5-fluoro-2,4-pyrimidinediamine; and N2,N4-bis[(3-chloro-4-methoxyphenyl))-5-fluoro-2,4-pyrimidinediamine.

[0064] In a fourth embodiment, the compounds of structural formulae (I) and (la) exclude compounds according to the following structural formula (lb):

<img file="IS2923B_D0035.tif" />

<img file="IS2923B_D0036.tif" />

<img file="IS2923B_D0037.tif" /> wherein R²⁴ is (C1-C6) alkyl; and R²¹, R²² and R²³ are as previously defined in connection with the first embodiment. [0065] In a fifth embodiment, the compounds of structural formulae (I) and (la) exclude the compounds described in Examples 1-141 of U.S. Patent No. 6,235,746.

[0066] In a sixth embodiment, the compounds of structural formulae (I) and (la) exclude compounds defined by formula (1) or formula 1(a) of this U.S. Patent No. 6,235,746 (see, e.g., the disclosure at Col. 1, line 48 through Col. 7, line 49 and Col. 8, lines 9-36).

[0067] In a seventh embodiment, the compounds of structural formulae (I) and (la) exclude compounds in which R⁵is cyano when R² is a substituted phenyl; R4 is a substituted or unsubstituted 5-15 membered heteroaryl; and R⁶ is hydrogen.

[0068] In an eighth embodiment, the compounds of structural formulae (I) and (la) excluded the compounds defined by formulae (I) and (X) of WO 02/04429 or any compound disclosed in WO 02/04429.

[0069] In a ninth embodiment of the compounds of structural formulae (I) and (la), when R⁵ is cyano; and R⁶ is hydrogen, then R² is other than a substituted phenyl group.

[0070] In a tenth embodiment, the compounds of structural formulae (I) and (la) exclude compounds in which R² and R⁴ are each independently a substituted or unsubstituted pyrrole or indole ring which is attached to the remainder of the molecule via its ring nitrogen atom.

[0071] In an eleventh embodiment, the compounds of structural formulae (I) and (la) exclude compounds defined by formulae (I) and (IV) of U.S. Patent No. 4,983,608 or any compound disclosed in U.S. Patent No. 4,983,608.

[0072] Those of skill in the art will appreciate that in the compounds of formulae (I) and (la), R² and R⁴ may be the same or different, and may vary broadly. When R² and/or R⁴ are optionally substituted rings, such as optionally substituted aryls and heteroaryls, the ring may be attached to the remainder of the molecule through any available carbon or heteroatom. The optional substituents may be attached to any available carbon atoms and/or heteroatoms.

[0073] In a twelfth embodiment of the compounds of structural formulae (I) and (la), R² and/or R⁴ is substituted phenyl subject to the provisos that (1) when R⁶ is hydrogen, then R² is not 3 ,4,5-timethoxyphenyl or 3,4,5-tri (C1-C6) alkoxy-phenyl; (2) when R² is a 3,4,5-trisubstituted phenyl, then the substituents at the 3- and 4-positions are not simultaneously methoxy or (C1-C6) alkoxy; or (3) when R⁶ is hydrogen and R⁴ is 5-15 membered heteroaryl, then R⁵ is other than cyano. Alternatively, R² is subject to the provisos described in connection with the first or second embodiments. The substituted phenyl group may be attached to the remainder of the molecule through any available carbon atom. Specific examples of optionally substituted phenyls include phenyls that are optionally mono-, di- or tri-substituted with the same or different R⁸ groups, where R⁸ is as previously defined for structural formula (I) and subject to the above provisos. When the phenyl is mono-substituted, the R⁸ substituent may be positioned at either the ortho., meta or para position. When positioned at the ortho, meta or para position, R⁸ is preferably selected from the group consisting of (C1-C10) alkyl, (C1-C10) branched alkyl, -OR^a optionally substituted with one or more of the same or different R^b groups, -O-C (O)OR^a, -O-(CH2)m-C(O)OR^a, -C(O)OR^a, -O-(CH2)_m-NRcR^c, -O-C(O)NR^CR^C, -O-(CH2)m-C(O)NR^cR^c, -O-C(NH)NR^CR^C, -O-(CH2)_m-C(NH)NR^cR^c and -NH-(CH₂)_m-NR^cR^c, where m, R^a and R^c are as previously defined for structural formula (I). In one embodiment of these compounds, -NR^CR^C is a 5-6 membered heteroaryl which optionally includes one or more of the same or different additional heteroatoms. Specific examples of such 5-6 membered heteroaryls include, but are not limited to, oxadiazolyl, triazolyl, thiazolyl, oxazolyl, tetrazolyl and isoxazolyl.

[0074] In anotherembodiment of these compounds, -NR^CR^C is a 5-6 membered saturated cycloheteroalkyl ring which optionally includes one or more of the same or different heteroatoms. Specific examples of such cycloheteroalkyls include, but are not limited to, pyrrolidinyl, pyrazolidinyl, imidazolidinyl, piperidinyl, piperazinyl and morpholinyl.

[0075] In still anotherembodiment ofthesecompounds, each R^a is independently a (C1-C6) alkyl and/oreach -NR^CR^Cis NHR^a, where R^a is a (C1-C6) alkyl. In one specific embodiment, R⁸ is -O-CH₂-C(O)NHCH₃. In another specific embodiment R⁸ is -OH.

[0076] When the phenyl is di-substituted or tri-substituted, the R⁸ substituents may be positioned at any combination of positions. For example, the R⁸ substituents may be positioned at the 2,3-, 2,4-, 2,5-, 2,6-, 3,4-, 3,5-, 2,3,4-, 2,3,5-, 2,3,6-, 2,4,5-, 2,4,6-, 2,5,6- or 3,4,5-positions. In one embodiment of compounds including a disubstituted phenyl, the substituents are positioned other than 3,4. In another embodiment they are positioned 3,4. In one embodíment of com-

<img file="IS2923B_D0038.tif" />

pounds including a trisubstituted phenyl, the substituents are positioned other than 3,4,5 or, alternatively, no two of the substituents are positioned 3,4. In another embodiment, the substituents are positioned 3,4,5.

[0077] Specific examples of R⁸ substituents in such di- and trisubstituted phenyls include the various R⁸ substituents described above in connection with the ortho, meta and para substituted phenyls.

[0078] In another specific embodiment, R⁸ substituents useful for substitituting such di-and trisubstituted phenyls include (C1-C6) alkyl, (C1-C6) alkoxy, methoxy, halo, chloro, (C1-C6) perhaloalkyl, -CF₃, (C1-C6) perhaloalkoxy and -OCF₃. In a preferred embodiment, such R⁸ substituents are positioned 3,4 or 3,5. Specific examples of preferred disubstituted phenyl rings include 3-chloro-4-methoxy-phenyl, 3-methoxy4-chlorophenyl, 3-chloro-4-trifluoromethoxy-phe-nyl, 3-trifluoromethoxy-4-chloro-phenyl, 3,4-dichloro-phenyl, 3,4-dimethoxyphenyl and 3,5-dimethoxyphenyl, with the provisos that: when R⁴ is 3-chloro-4-methoxyphenyl and R⁵ is halo or fluoro, and R⁶ is hydrogen, then R² is not 3-chloro-4-(C1-C6)alkoxyphenyl or 3-chloro-4-methooxyphenyl; and/or (2) R² and/or R⁴ is not 3,4,5-tri(C1-C6)alkoxyphenyl or 3,4,5-trimethoxyphenyl, [0079] In another embodiment of compounds including a trisubstituted phenyl, the trisubstituted phenyl has the formula: <img file="IS2923B_D0039.tif" /> wherein: R³¹ is methyl or (C1-C6) alkyl; R³² is hydrogen, methyl or (C1-C6) alkyl; and R³³ is a halo group.

[0080] In a thirteenth embodiment of the compounds of structural formulae (I) and (Ia), R² and/or R⁴ is an optionally substituted heteroaryl as defined in claim 1. Typical heteroaryl groups according to this thirteenth embodiment comprise from 5 to 15, and more typically from 5 to 11 ring atoms, and include one, two, three or four of the same or different heteratoms or heteroatomic groups selected from the group consisting of N, NH, O, S, S(O) and S(O)₂. The optionally substituted heteroaryl may be attached to its respective C2 or C4 nitrogen atom or linker L¹ or L² through any available carbon atom or heteroatom, but is typically attached via a carbon atom. The optionally substituents may be the same or different, and may be attached to any available carbon atom or heteroatom. In one embodiment of these compounds, R⁵ isotherthan bromo, trifluoromethyl orcyano. In another embodiment of these compounds, when R²and R⁴ are each a substituted or unsubstituted indole, then the ring is attached to the remainder of the molecule via a ring carbon atom. In still another embodiment of compounds including an optionally substituted heteroaryl group, the heteroaryl is unsubstituted or substituted with from one or four of the same or different R⁸ groups, where R⁸ is as previously defined for structural formula (I). The following are heteroaryl groups from which R² and R⁴ may be seiected: <img file="IS2923B_D0040.tif" />

<img file="IS2923B_D0041.tif" />

<img file="IS2923B_D0042.tif" />

<img file="IS2923B_D0043.tif" />

<img file="IS2923B_D0044.tif" />

wherein:<img file="IS2923B_D0045.tif" /> p is an integer from one to three;

each — independently represents a single bond or a double bond;

R³⁵ is hydrogen or R⁸, where R⁸ is as previously defined for structural formula (I);

X is selected from the group consisting of CH, N and N-O;

each Y is independently selected from the group consisting of O, S and NH;

each Y¹ is independently selected from the group consisting of O, S, SO, SO₂, SONR³⁶, NH and NR³⁷;

each Y² is independently selected from the group consisting of CH, CH₂, O, S, N, NH and NR³⁷;

R³⁶ is hydrogen or alkyl;

R³⁷ is selected from the group consisting of hydrogen and a progroup, preferably hydrogen or a progroup selected from the group consisting of aryl, arylalkyl, heteroaryl, R^a, R^b-CR^aR^b-O-C(O)R⁸, -CR^aR^b-O-PO(OR⁸)2, -CH2-O-PO (OR⁸)2,- CH₁-PO(OR⁸)2, -C(O)-CR^aR^b-N(CH3)₂, -CR^aR^b-O-C(O)-CR^aR^b-N(CH3)2, -C(O)R⁸, -C(O)CF3 and -C (O)-NR⁸-C(O)R⁸;

A is selected from the group consisting of Ο, NH and NR³⁸;

R³⁸ is selected from the group consisting of alkyl and aryl;

R⁹, R¹⁰, R¹¹ and R¹² are each, independently of one another, selected from the group consisting of alkyl, alkoxy, halogen, haloalkoxy, aminoalkyl and hydroxyalkyl, or, alternatively, R⁹ and R¹⁰and/orR¹¹ and R¹² are taken together form a ketal;

each Z is selected from the group consisting of hydroxyl, alkoxy, aryloxy, ester and carbamate;

Q is selected from the group consisting of-OH, OR⁸, -NR^CR^C, -NHR³⁹-C(O)R⁸, -NHR³⁹-C(O)OR⁸, -NR³⁹-CHR⁴⁰-R^b, -NR³⁹-(CH₂)_m-R^b and -NR³⁹-C(O)-CHR⁴°-NR^CR^C;

R³⁹ and R⁴⁰ are each, independently of one another, selected from the group consisting of hydrogen, alkyl, aryl, alkylaryl;arylalkyl and NHR⁸; and

R^a, R^b and R^c are as previously defined for structural formula (I). Preferred R^b substitutents for Q are selected from -C(O)OR⁸, -O-C(O)R⁸, -O-P(O)(OR⁸)2 and -P(O)(OR⁸)2.

[0081] In one embodiment of the above-depicted heteroaryls, as well as other 5-15 membered heteroaryls according to this embodiment of The invention, each R⁸ is independently selected from the group consisting of R^d, -NR^CR^C, -(CH2)m-NR^cR^c, -C(O)NR^CR^C, -(CH2)_m-C(O)NR^cR^c, -C(O)OR^d, -(CH2)m-C(O)OR^d and -(CH2)_m-OR^d, where m, R^c and R^d are as previously defined for structural formula (I).

[0082] In a specific embodiment, R^d and/or R^c is selected from the group consisting of R^a and (C3-C8) cycloalkyl optionally substituted with one or more of the same or different hydroxyl, amino or carboxyl groups.

[0083] In another embodiment of the above-depicted heteroaryls, each R³⁵ is a hydrogen atom, a (C1-C6) carbon chain, including methyl, ethyl, isopropyl, a cycloalkyl group, including cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, a <img file="IS2923B_D0046.tif" /> wherein x =1-8, -CH₂CONHMe, -CH₂CH₂NHMe, - CH₂CH₂CONHMe, -CH₂CH₂CH₂NHMe or-CH₂CH₂CH₂OCH₃. [0084] In still another embodiment of the above-depicted heteroaryls, the aromatic ring connectivity is either at the 5 or 6 position. It should be understood that either R² or R⁴ can utilíze the heteroaryl groups discussed throughout this specification.

[0085] In a fourteenth embodiment of the compounds of structural formulae (I) and (la), R² and R⁴ are each, independently of one another, an optionally substituted phenyl, aryl or heteroaryl, with the proviso that: (1) when L¹ is a direct bond and R⁶ and optionally R⁵ is hydrogen, then R² is other than 3,4,5-trimethoxyphenyl or 3,4,5-tri(C1-C6)alkoxyphenyl; (2) when L¹ and L² are each a direct bond, R⁶ is hydrogen and R⁵ is halo, then R² and R⁴ are not each simultaneously

<img file="IS2923B_D0047.tif" />

<img file="IS2923B_D0048.tif" />

3,4,5-trimethoxyphenyl or 3,4,5-tri(C1-C6)alkoxyphenyl; (3) when R⁴ is 3-methoxyphenyl or 3-(C1-C6)alkoxyphenyl and R² is a 3,4,5-trisubstituted phenyl, the substituents positioned at the 3 and 4 positions are not both simultaneously methoxy or (C1-C6) alkoxy; (4) when R² is a substituted phenyl and R⁶ is hydrogen, then R⁵ is other than cyano or -C (O)NHR, where R is hydrogen or (C1-C6)alkyl; and/or (5) when R² and R⁴ are each independently a substituted or unsubstituted indole, then the indole is attached to the remainder of the molecule via a ring carbon atom. Alternatively, R² is subject to the provisos described in connection with the first or second embodiment.

[0086] I n this fourteenth embodiment of The invention, the R² and R⁴ substituents may be the same or different. Specific optionally substituted phenyl, aryl and/or heteroaryls include those illustrated above in connection with the twelfth and thirteenth embodiments.

[0087] In a fifteenth embodiment of the compounds of structural formulae (I) and (la), including the above-described first through fourteenth embodiments thereof, R⁶ is hydrogen and R⁵ is an electronegative group. As will be recognized by skilled artisans, electronegative groups are atoms or groups of atoms that have a relatively great tendency to attract electrons to themselves. Specific examples of electronegative groups according to this fourteenth embodiment include, but are not limited to, -CN, -NC, -NO2, halo, bromo, chloro, fluoro, (C1-C3) haloalkyl, (C1-C3) perhaloalkyl, (C1-C3) fluoroalkyl, (C1-C3) perfluoroalkyl, -CF3, (C1-C3) haloalkoxy, (C1-C3) perhaloalkoxy, (C1-C3) fluoroalkoxy, (C1-C3) perfluoroalkoxy, -OCF3, -C(O)R^a, -C(O)OR^a, -C(O)CF3 and -C(O)OCF₃. In a specific embodiment, the electronegative group is a halogen-containing electronegative group, such as -OCF₃, -CF₃, bromo, chloro or fluoro. In another specific embodiment, R⁵ is fluoro, subject to the proviso that the compound is not any compound according to the third embodiment.

[0088] In a sixteenth embodiment, the compounds of structural formulae (I) and (la) are compounds according to structural formula (lb):

<img file="IS2923B_D0049.tif" /> and salts, hydrates, solvates and N-oxides thereof, wherein R¹¹ and R¹⁴ are each, independently of one another, selected from the group consisting of hydroxy, (C1-C6) alkoxy and -NR^CR^C; R¹² and R¹³ are each hydrogen and R⁵, R⁶ and R^care as previously defined for structural formula (I).

[0089] In a seventeenth embodiment, the compounds of structural formulae (I) and (la) are compounds according to structural formula (lc):

<img file="IS2923B_D0050.tif" /> and salts, hydrates, solvates and N-oxides thereof, wherein:

R⁴ is selected from the group consisting of 5-10 membered heteroaryl and 3-hydroxyphenyl;

R⁵ is F or-CF₃; and

R⁸ is -O(CH2)m-R^b, where m and R^b are as previously defined for structural formula (I). In a specific embodiment, R⁸ is -O-CH2-C(O)NH-CH₃ and/or R⁴ is a heteroaryl according to the thirteenth embodiment.

[0090] In an eighteenth embodiment, the compounds of structural formulae (I) and (I a) include any compound selected from TABLE 1 that inhibits an Fc receptor signal transduction cascade, a Syk kinase activity, a Syk-kinase dependent receptor signal transduction cascade orcell degranulation as measured in an in vitro assay, optionally subject to the proviso that the compound is not a compound excluded by the above-described third embodiment and/or other embodiments. In a specific embodiment, such compounds have an IC₅₀ of about 20 μΜ or less as measured in an in vitro degranulation assay, such as one of the degranulation assays described in the Examples section.

<img file="IS2923B_D0051.tif" />

<img file="IS2923B_D0052.tif" />

[0091] In a nineteenth embodiment, the compounds of structural formulae (I) and (la) include any compound selected from TABLE 1 that inhibits the FcyR1 or FcyR1 receptor cascade with an IC₅₀ of about 20 μΜ or less as measured in an in vitro assay, such as one of the in vitro assays provided in the Examples section, optionally subject to the proviso that the compound is not a compound excluded by the above-described third embodiment and/or other embodiments. [0092] In a twentieth embodiment, the compounds of structural formulae (la) are those wherein R² is selected from the group consisting of <img file="IS2923B_D0053.tif" /> [0093] R⁴, R⁸, R^a, R^b, R^c, R^d are as described above, R⁵ is a fluorine atom; R⁶ is a hydrogen atom and each R²¹ is independently a halogen atoms or an alkyl optionally substituted with one or more of the same or different halo groups, R²² and R²³ are each, independently of one another, a hydrogen atom, methyl or ethyl optionally substituted with one ormoreofthesameordifferent halogroups, each mis independently an integerfrom 1 to 3, and each n is independently an integer from 0 to 3.

[0094] In a twenty first embodiment, the compounds of structural formulae (la) are those wherein R⁴ is <img file="IS2923B_D0054.tif" /> wherein R⁹ and R¹⁰ are as defined above and further include, each independently a hydrogen atom, and R² is a phenyl group, substituted with one or more of the same R⁸ groups, or <img file="IS2923B_D0055.tif" /> wherein R³⁵ is as defined above. In one particular aspect, when R² is a phenyl group, one or more of R⁸ is selected from a halogen and an alkoxy group. In one aspect, the phenyl group is di or tri substituted with one or more of the same R⁸ groups.

[0095] In a twenty second embodiment, the compounds of structural formulae (la) are those wherein R⁴ is <img file="IS2923B_D0056.tif" />

<img file="IS2923B_D0057.tif" />

<img file="IS2923B_D0058.tif" />

<img file="IS2923B_D0059.tif" />

<img file="IS2923B_D0060.tif" />

and R² is a phenyl group, substituted with one or more of the same R⁸ groups. In one particular aspect, one or more of R⁸ is selected from a halogen and an alkoxy group. In one aspect, the phenyl group is di or tri substituted with one or more of the same R⁸ groups.

[0096] Ina twenty third embodiment, the compoundsof structural formulae (la) arethose wherein R⁴ is a phenyl group substituted with one or more of the same R⁸ groups, wherein R² is <img file="IS2923B_D0061.tif" /> wherein R³⁵ is as defined above. In particularembodiments, the R⁴ phenyl group is di ortri substituted with the the same or different halgoen atoms. In another embodiment, R⁴ is a monosubstituted phenyl group with a halogen atom. In one aspect, R³⁵ is a hydroxyalkyl group. In certain aspects, the hydroxyalkyl group can be further functionalized into an ester group, carbamate, etc.

[0097] In a twenty fourth embodiment, the compounds of structural formulae (la) are those wherein R⁴ is <img file="IS2923B_D0062.tif" /> wherein R³⁵ is as defined above and R² is a phenyl group substituted with one or more of the same R⁸ groups. In one particular aspect, R³⁵ is a hydrogen atom or an alkyl group. In another aspect, the R² phenyl group is di or tri substituted with the same or different R⁸ groups, and in particular, halogen atoms.

[0098] In a twenty fifth embodiment, the compounds of structural formulae (la) are those wherein R⁴ is wherein R³⁵ is as defined above and R² is<img file="IS2923B_D0063.tif" /> wherein R⁹ and R¹⁰ are defined as above and further include, each independently a hydrogen atom. In one aspect, R³⁵is a hydrogen atom or an alkyl group, e.g., methyl and R⁹ and R¹⁰ are alkyl groups, e.g., methyl groups.

[0099] In a twenty sixth embodiment, the compounds of structural formulae (la) are those wherein R⁴ is a disubstituted phenyl group, substituted with the same or different R⁸ groups and R² is <img file="IS2923B_D0064.tif" />

<img file="IS2923B_D0065.tif" />

<img file="IS2923B_D0066.tif" />

<img file="IS2923B_D0067.tif" />

<img file="IS2923B_D0068.tif" />

wherein R³⁵ is as defined above. In certain aspects, the phenyl group is substituted with a halogen atom and an alkyoxy group, e.g. a methoxy group. In certain embodiments, R³⁵ is a hydrogen atom, an alkyl group, e.g., a methyl group, or a hydroxyalkyl group. In certain aspects, the hydroxyalkyl group can be further functionalized into an ester group, carbamate, etc.

[0100] In a twenty seventh embodiment, the compounds of structural formulae (la) are those wherein R⁴ is <img file="IS2923B_D0069.tif" /> wherein R⁸ and R^c are as defined above and R² is a phenyl group that is substituted with one or more of the same R⁸groups. In one particular aspect, R^c is a hydrogen atom or an alkyl group. In another aspect, the R² phenyl group is di or tri substituted with the same or different R⁸ aroups, and in<img file="IS2923B_D0070.tif" />particular, haloaen atoms or [0101] In a twenty eighth embodiment, the compounds of structural formulae (la) are those wherein R⁴ is <img file="IS2923B_D0071.tif" /> wherein Y¹, Y² and each R³⁵ independently, are defined as above and R² is <img file="IS2923B_D0072.tif" /> wherein R³⁵ is as defined above. In one aspect of the twenty eighth embodiment with regard to R⁴, Y¹ is oxygen, Y² is NH and one or more of R³⁵ or the R⁴ moiety is an alkyl group, and in particular, a methyl group. In certain aspects of the twenty eighth embodiment, two R³⁵’s of the R⁴ moiety form a gem dialkyl moiety, in particular, a gem dimethyl moiety adjacent to the NH depicted as <img file="IS2923B_D0073.tif" />

In certain aspects of the twenty eighth embodiment, with regard to R², R³⁵ is a hydrogen atom or an alkyl group, and in particular, a methyl group.

[0102] In a twenty nineth embodiment, the compounds pf structural formulae (la) are those wherein R⁴ is

<img file="IS2923B_D0074.tif" />

<img file="IS2923B_D0075.tif" />

<img file="IS2923B_D0076.tif" />

<img file="IS2923B_D0077.tif" />

<img file="IS2923B_D0078.tif" />

<img file="IS2923B_D0079.tif" /> wherein R⁹ and R¹⁰ are as defined above or a substituted phenyl group. In one aspect the phenyl group is di or tri substituted with one or more of the same R⁸ groups. In particular, the phenyl group can be di or tri substituted with one or more halogen atoms that can be the same or different. R² in the twenty nineth embodiment is <img file="IS2923B_D0080.tif" /> wherein R³⁵ is as defined above. In one aspect of the twenty nineth embodiment, R³⁵ of R² is not a methyl group. In another still another aspect of the twenty nineth embodiment, R² is <img file="IS2923B_D0081.tif" /> [0103] In a thirtieth embodiment, applicable to the first through twenty nineth embodiments, R⁵ is a halogen atom, such as fluorine, and R⁶ is a hydrogen atom.

[0104] Also specifically described are combinations of the above first through thirtieth embodiments.

[0105] Those of skill in the art will appreciate that the 2,4-pyrimidinediamine compounds described herein may include functional groups that can be masked with progroups to create prodrugs. Such prodrugs are usually, but need not be, pharmacologically inactive until converted into their active drug form. Indeed, many of the active 2,4-pyrimidinediamine compounds described in TABLE 1, infra, include promoieties that are hydrolyzable or otherwise cleavable under conditions of use. For example, ester groups commonly undergo acid-catalyzed hydrolysis to yield the parent carboxylic acid when exposed to the acidic conditions of the stomach, or base-catalyzed hydrolysis when exposed to the basic conditions of the intestine or blood. Thus, when administered to a subject orally, 2,4-pyrimidinediamines that include ester moieties may be considered prodrugs of their corresponding carboxylic acid, regardless of whether the ester form is pharmacologically active. Referring to TABLE 1, numerous ester-containing 2,4-pyrimidinediannines of The invention are active in their ester, "prodrug" form.

[0106] In the prodrugs, any available functional moiety may be masked with a progroup to yield a prodrug. Functional groups within the 2,4-pyrimidinediamine compounds that may be masked with progroups for inclusion in a promoiety include, but are not limited to, amines (primary and secondary), hydroxyls, sulfanyls (thiols), carboxyls, etc. Myriad progroups suitable for masking such functional groups to yield promoieties that are cleavable under the desired conditions of use are known in the art. All of these progroups, alone or in combinations, may be included in the prodrugs [0107] In one illustrative example, the prodrugs are compounds according to structural formula (I) in which R^a and R^dmay be, in addition to their previously-defined alternatives, a progroup.

[0108] Replacing the hydrogens attached to N2 and N4 in the 2,4-pyrimidinediamines of structural formula (I) with substituents adversely effects the activity of the compounds. However, as will be appreciated by skilled artisans, these nitrogens may be included in promoieties that, under conditions of use, cleave to yield 2,4-pyrimidinediamines according to structural formula (I). Thus, in another embodiment, the prodrugs compounds according to structural formula (II):

<img file="IS2923B_D0082.tif" />

<img file="IS2923B_D0083.tif" />

<img file="IS2923B_D0084.tif" />

<img file="IS2923B_D0085.tif" /> including salts, hydrates, solvates and N-oxides thereof, wherein:

R², R⁴, R⁵, R⁶, L¹ and L² are as previously defined for structural formula (I); and

R^2b and R^4b are each, independently of one another, a progroup. Specific examples of such progroups include, but are not limited to, (C1-C6) alkyl, -C(O)CH3, -C(O)NHR³⁸ and -S(O)2R³⁶, where R³⁶ is (C1-C6) alkyl, (C5-C15) aryl and (C3-C8) cycloalkyl.

[0109] In the prodrugs of structural formula (II), the various substituents may be as described for the various first through twentieth embodiments previously described for the compounds of structural formulae (I) and (Ia), or combinations of such embodiments.

[0110] Those of skill in the art will appreciate that many of the compounds and prodrugs, as well as the various compound species specifically described and/or illustrated herein, may exhibitthe phenomena of tautomerism, conformational isomerism, geometric isomerism and/or optical isomerism. For example, the compounds and prodrugs may include one or more chiral centers and/or double bonds and as a consequence may exist as stereoisomers, such as double-bond isomers (i.e., geometric isomers), enantiomers and diasteromers and mixtures thereof, such as racemic mixtures. As another example, the compounds and prodrugs may exist in several tautomeric forms, including the enol form, the keto form and mixtures thereof. As the various compound names, formulae and compound drawings within the specification and claims can represent only one of the possible tautomeric, conformational isomeric, optical isomeric or geometric isomeric forms, it should be understood that The invention encompasses any tautomeric, conformational isomeric, optical isomeric and/or geometric isomeric forms of the compounds or prodrups having one or more of the utilities described herein, as well as mixturesofthese various different isomericforms. In cases of limited rotation around the 2,4-pryimidinediamine core structure, atrop isomers are also possible and are also specifically included in the compounds of The invention [0111] Moreover, skilled artisans will appreciate that when lists of alternative substituents include members which, owing to valency requirements or other reasons, cannot be used to substitute a particular group, the list is intended to be read in contextto include those membersof the listthataresuitableforsubstituting the particulargroup. Forexample, skilled artisans will appreciate that while all of the listed alternatives for R^b can be used to substitute an alkyl group, certain of the alternatives, such as =0, cannot be used to substitute a phenyl group. It is to be understood that only possible combinations of substituent-group pairs are intended.

[0112] The compounds and/or prodrugs may be identified by either their chemical structure or their chemical name. When the chemical structure and the chemical name conflict, the chemical structure is determinative of the identity of the specific compound.

[0113] Depending upon the nature of the various substituents, the 2,4-pyrimidinediamine compounds and prodrugs of The invention may be in the form of salts. Such salts include salts suitable for pharmaceutical uses ("pharmaceutically-acceptable salts"), salts suitable for veterinary uses, etc. Such salts may be derived from acids or bases, as is well-known in the art.

[0114] In one embodiment, the salt is a pharmaceutically acceptable salt. Generally, pharmaceutically acceptable salts are those salts that retain substantially one or more of the desired pharmacological activities of the parent compound and which are suitable for administration to humans. Pharmaceutically acceptable salts include acid addition salts formed with inorganic acids or organic acids. Inorganic acids suitable for forming pharmaceutically acceptable acid addition saltsinclude, bywayofexampleand notlimitation, hydrohalide acids(e.g., hydrochloricacid, hydrobromicacid, hydriodic, etc.),sulfuricacid, nitricacid, phosphoricacid, andthelike.Organicacidssuitableforformingpharnnaceuticallyacceptable acid addition salts include, by wayof exampleand not limitation, aceticacid, trifluoroaceticacid, propionicacid, hexanoic acid, cyclopentanepropionic acid, glycolic acid, oxalic acid, pyruvic acid, lactic acid, malonic acid, succinic acid, malic acid, maleic acid, fumaric acid, tartaric acid, citric acid, palmitic acid, benzoic acid, 3-(4-hydroxybenzoyl) benzoic acid, cinnamic acid, mandelic acid, alkylsulfonic acids (e.g., methanesulfonic acid, ethanesulfonic acid, 1,2-ethane-disulfonic acid, 2-hydroxyethanesulfonic acid, etc.), arylsulfonic acids (e.g., benzenesulfonic acid, 4-chlorobenzenesulfonic acid, 2-naphthalenesulfonicacid, 4-toluenesulfonicacid, cycloalkylsulfonic acids (e.g., camphorsulfonicacid), 4-methylbicyclo

<img file="IS2923B_D0086.tif" />

[2.2.2]-oct-2-ene-1-carboxylic acid, glucoheptonic acid, 3-phenylpropionic acid, trimethylacetic acid, tertiary butylacetic acid, lauryl sulfuric acid, gluconic acid, glutamic acid, hydroxynaphthoic acid, salicylic acid, stearic acid, muconic acid, and the like.

[0115] Pharmaceutically acceptable salts also include salts formed when an acidic proton present in the parent compound is either replaced by a metal ion (e.g., an alkali metal ion, an alkaline earth metal ion or an aluminum ion), an ammonium ion or coordinates with an organic base (e.g., ethanolamine, diethanolamine, triethanolamine, N-methylglu-camine, morpholine, piperidine, dimethylamine, diethylamine, etc.).

[0116] The 2,4-pyrimidinediamine compounds and of The invention, as well as the salts thereof, may also be in the form of hydrates, solvates and N-oxides, as are well-known in the art.

6.3 Methods of Synthesis [0117] The compounds, and prodrugs may be synthesized via a variety of different synthetic routes using commercially available starting materials and/or starting materials prepared by conventional synthetic methods. Suitable exemplary methods that may be routinely adapted to synthesize the 2,4-pyrimidinediamine compounds and prodrugs of the in vention are found in U.S. Patent No. 5,958,935, the disclosure of which is incorporate herein by reference. Specific examples describing the synthesis of numerous compounds and prodrugs, as well as intermediates therefor, are provided in the Examples section. All of the compounds of structural formulae (I), (la) and (II) may be prepared by routine adaptation of these methods.

[0118] A variety of exemplary synthetic routes that can be used to synthesize the 2,4-pyrimidinediamine compounds of The invention are described in Schemes (l)-(XI), below. In Schemes (l)-(XI), like-numbered compounds have similar structures. These methods may be routinely adapted to synthesize the prodrugs according to structural formula (II).

[0119] In one exemplary embodiment, the compounds can be synthesized from substituted or unsubstituted uracils or thiouracils as illustrated in Scheme (I), below:

Scheme (I) <img file="IS2923B_D0087.tif" /> [0120] ln Scheme (I), R², R⁴, R⁵, R⁶, L¹ and L² are as previously defined for structural formula (I), X is a halogen (e.g., F, Cl, Br or I) and Y and Y’ are each, independently of one another, selected from the group consisting of O and S. Referring to Scheme (I), uracil or thiouracil 2 is dihalogenated at the 2- and 4-positions using standard halogenating agent POX₃ (or other standard halogenating agent) under standard conditions to yield 2,4-bishalo pyrimidine 4. Depending upon the R⁵ substituent, in pyrimidine 4, the halide at the C4 position is more reactive towards nucleophiles than the halide at the C2 position. This differential reactivity can be exploited to synthesize 2,4-pyrimidinediamines according structural formula (I) by first reacting 2,4-bishalopyrimidine 4 with one equivalent of amine 10, yielding 4N-substituted-2-halo-4-pyrimidineamine 8, followed by amine 6 to yield a 2,4-pyrimidinediamine according structural formula (I). 2N, 4N-bis(substituted)-2,4-pyrimidinediamines 12 and 14 can be obtained by reacting 2,4-bishalopyrimidine 4 with excess 6 or 10, respectively.

[0121] In most situations, the C4 halide is more reactive towards nucleophiles, as illustrated in the Scheme. However, as will be recognized by skilled artisans, the identity of the R⁵ substituent may alter this reactivity. For example, when R⁵ is trifluoromethyl, a 50:50 mixture of 4N-substituted-4-pyrimidineamine 8 and the corresponding 2N-substituted-2-pyrimidineamine is obtained. Regardless of the identity of the R⁵ substituent, the regioselectivity of the reaction can be controlled by adjusting the solvent and other synthetic conditions (such as temperature), as is well-known in the art.

[0122] The reactions depicted in Scheme (I) may proceed more quickly when the reaction mixtures are heated via microwave. When heating in this fashion, the following conditions may be used: heat to 175°C in ethanol for 5-20 min. in a Smith Reactor (Personal Chemistry) in a sealed tube (at 20 bar pressure).

[0123] The uracil or thiouracil 2 starting materials may be purchased from commercial sources or prepared using standard techniques of organic chemistry. Commercially available uracils and thiouracils that can be used as starting materials in Scheme (I) include, by way of example and not limitation, uracil (Aldrich #13,078-8; CAS Registry 66-22-8); 2-thio-uracil (Aldrich #11,558-4; CAS Registry 141-90-2); 2,4-dithiouracil (Aldrich #15,846-1; CAS Registry 2001-93-6);

5-acetouracil (Chem. Sources lnt’12000; CAS Registry 6214-65-9); 5-azidouracil; 5-aminouracil (Aldrich #85,528-6; CAS

<img file="IS2923B_D0088.tif" />

Registry 932-52-5); 5-bromouracil (Aldrich #85,247-3; CAS Registry 51-20-7); 5-(trans-2-bromovinyl)-uracil (Aldrich #45,744-2; CAS Registry 69304-49-0); 5-(trans-2-chlorovinyl)-uracil (CAS Registry 81751-48-2); 5-(trans-2-carboxyvi-nyl)-uracil; uracil-5-carboxylic acid (2,4-dihydroxypyrimidine-5-carboxylic acid hydrate; Aldrich #27,770-3; CAS Registry 23945-44-0); 5-chlorouracil (Aldrich #22,458-8; CAS Registry 1820-81-1); 5-cyanouracil (Chem. Sources lnt’12000; CAS Registry 4425-56-3); 5-ethyluracil (Aldrich #23,044-8; CAS Registry 4212-49-1); 5-ethenyluracil (CAS Registry 37107-81-6); 5-fluorouracil (Aldrich #85,847-1; CAS Registry 51-21-8); 5-iodouracil (Aldrich #85,785-8; CAS Registry 696-07-1); 5-methyluracil (thymine; Aldrich #13,199-7; CAS Registry 65-71-4); 5-nitrouracil (Aldrich #85,276-7; CAS Registry 611-08-5); uracil-5-sulfamic acid (Chem. Sources lnt’12000; CAS Registry 5435-16-5); 5-(trifluoromethyl)-uracil (Aldrich #22,327-1; CAS Registry 54-20-6); 5-(2,2,2-trifluoroethyl)-uracil (CAS Registry 155143-31-6); 5-(pentafluoroe-thyl)-uracil (CAS Registry 60007-38-3); 6-aminouracil (Aldrich #A5060-6; CAS Registry 873-83-6) uracil-6-carboxylic acid (orotic acid; Aldrich #0-840-2; CAS Registry 50887-69-9); 6-methyluracil (Aldrich #D11,520-7; CAS Registry 626-48-2); uracil-5-amino-6-carboxylic acid (5-aminoorotic acid; Aldrich #19,121 -3; CAS Registry #7164-43-4);. 6-amino-

5- nitrosouracil (6-amino-2,4-dihydroxy-5-nitrosopyrimidine; Aldrich #27,689-8; CAS Registry 5442-24-0); uracil-5-fluoro-

6- carboxylic acid (5-fluoroorotic acid; Aldrich #42,513-3; CAS Registry 00000-00-0); and uracil-5-nitro-6-carboxylic acid (5-nitroorotic acid; Aldrich #18,528-0; CAS Registry 600779-49-9). Additional 5-, 6- and 5,6-substituted uracils and/or thiouracils are available from General Intermediates of Canada, Inc., Edmonton, Alberta, CA (www. generalintermedi-ates.com) and/or Interchim, France (www.interchim.com), or may be prepared using standard techniques. Myriad textbook references teaching suitable synthetic methods are provided infra.

[0124] Amines 6 and 10 may be purchased from commercial sources or, alternatively, may be synthesized utilizing standard techniques. For example, suitable amines may be synthesized from nitro precursors using standard chemistry. Specific exemplary reactions are provided in the Examples section. See also Vogel, 1989, Practical Organic Chemistry, Addison Wesley Longman, Ltd. and John Wiley &amp; Sons, Inc.

[0125] Skilled artisans will recognize that in some instances, amines 6 and 10 and/or substituents R⁵ and/or R⁶ on uracil or thiouracil 2 may include functionaí groups that require protection during synthesis. The exact identity of any protecting group(s) used will depend upon the identity of the functional group being protected, and will be apparent to these of skill in the art. Guidance for selecting appropriate protecting groups, as well as synthetic strategies for their attachment and removal, may be found, for example, in Greene &amp; Wuts, Protective Groups in Organic Synthesis, 3d Edition, John Wiley &amp; Sons, Inc., New York (1999) and the references cited therein (hereinafter "Greene &amp; Wuts"). [0126] Aspecific embodimentofScheme(l)utilizing5-fluorouracil(Aldrich #32,937-1 )asastartingmaterialisillustrated in Scheme (la), below:

Schemc(Ia) <img file="IS2923B_D0089.tif" /> [0127] ln Scheme (la), R², R⁴, L¹ and L² are as previously defined for Scheme (I). According to Scheme (la), 5-fluoromuracil 3 is halogenated with POCI₃ to yield 2,4-dichloro-5-fluoropyrimidine 5, which is then reacted with excess amine 6 or 10 to yield N2,N4-bis substituted 5-fluoro-2,4-pyrimidinediamine 11 or 13, respectively. Alternatively, asymmetric 2N,4N-disubstitubed 5-fluoro-2,4-pyrimidinediamine 9 may be obtained by reacting 2,4-dichloro-5-fluoropyrimi-dine 5 with one equivalent of amine 10 (to yield 2-chloro-N4-substituted-5-fluoro-4-pyrimidineamine 7) followed by one or more equivalents of amine 6.

[0128] In another exemplary embodiment, the 2,4-pyrimidinediamine compounds may be synthesized from substituted or unsubstituted cytosines as illustrated in Schemes (lla) and (llb), below:

<img file="IS2923B_D0090.tif" />

Scheme (Ila) <img file="IS2923B_D0091.tif" /> [0129] In Schemes (lla) and (llb), R², R⁴, R⁵, R⁶,L¹, L² and X are as previously defined for Scheme (I) and PG represents a protecting group. Referring to Scheme (lla), the C₄ exocyclic amine of cytosine 20 is first protected with a suitable protecting group PG to yield N4-protected cytosine 22. For specific guidance regarding protecting groups useful in this context, see Vorbríiggen and Ruh-Pohlenz, 2001, Handbook of Nucleoside Synthesis, John Wiley &amp; Sons, NY, pp. 1 -631 ("Vorbruggen"). Protected cytosine 22 is halogenabed at the C2 position using a standard halogenation reagent under standard conditions to yield 2--chloro-4N-protected4-pyrimidineamine 24. Reaction with amine 6 followed by

<img file="IS2923B_D0092.tif" />

deprotection of the C4 exocyclic amine and reaction with amine 10 yields a 2,4-pyrimidinediamine according to structural formula (I).

[0130] Alternatively, referring to Scheme (llb), cytosine 20 may be reacted with amine 10 or protected amine 21 to yield N4-substituted cytosine 23 or 27, respectively. These substituted cytosines may then be halogenated as previously described, deprotected (in the case of N4-substituted cytosine 27) and reacted with amine 6 to yield a 2.4-pyrimidine-diamine according to stuctural formula (I).

[0131] Commercially-available cytosines that may be used as starting materials in Schemes (lla) and (llb) include, but are not limited to, cytosine (Aldrich #14,201-8; CAS Registry 71-30-7); N⁴-acetylcytosine (Aldrich #37,791-0; CAS Registry 14631-20-0); 5-fluorocytosine (Aldrich #27,159-4; CAS Registry 2022-85-7); and 5-(tifluoromethyl)-cytosine. Othersuitable cytosine useful asstarting materials in Schemes (lla) are available from General Intermediatesof Canada, Inc., Edmonton, Alberta, CA (www.generalintermediates.com) and/or Interchim, France www.interchim.com, or may be prepared using standard techniques. Myriad textbook reference teaching suitable synthetic methods are provided infra. [0132] In still another exemplary embodiment, the 2,4-pyrimidinediamine compounds may be synthesized from substituted or unsubstituted 2-amino-4-pyrimidinols as illustrated in Scheme (III), below:

Scheme (IH) <img file="IS2923B_D0093.tif" /> [0133] In Scheme (III), R², R⁴, R⁵, R⁶, L¹, L² and X are as previously defined for Scheme (I) and Z is a leaving group as discussed in more detail in connection with Scheme IV, infra. Referring to Scheme (III), 2-amino-4-pyrimidinol 30 is reacted with amine 6 (or optionally protected amine 21) to yield N2-substituted-4-pyrimidinol 32, which is then halogenated as previously described to yield N2-substituted-4-halo-2-pyrimidineamine 34. Optional deprotection (for example if protected amine 21 was used in the first step) followed by reaction with amine 10 affords a 2,4-pyrimidinediamine according to structural formula (I). Alternatively, pyrimidinol 30 can be reacted with acylating agent 31.

[0134] Suitable commercially-available 2-amino-4-pyrimidinols 30 that can be used as starting materials in Scheme (III) include, but are not limited to, 2-amino-6-chloro-4-pyrimidinol hydrate (Aldrich #A4702-8; CAS Registry 00000-00-0) and 2-amino-6-hydroxy-4-pyrimidinol (Aldrich #A5040-1; CAS Registry 56-09-7). Other 2-amino-4-pyrimidinols 30 useful as starting materials in Scheme (III) are available from General Intermediates of Canada, Inc., Edmonton, Alberta, CA (www.generalintermediates.com) and/or Interchim, France www.interchim.com), or may be prepared using standard techniques. Myriad textbook references teaching suitable synthetic methods are provided infra.

[0135] Alternatively, the 2,4-pydmidmediamme compounds may be prepared from substituted or unsubstituted 4-ainmo-2-pyrimidinols as illustrated in Scheme (IV), below:

<img file="IS2923B_D0094.tif" />

Scheme (IV) <img file="IS2923B_D0095.tif" /> [0136] ln Scheme (IV). R², R⁴, R⁵, R⁶, L¹ and L² are as previously defined for Scheme (I) and Z represents a leaving group. Referring to Scheme (IV), the C2-hydroxyl of 4-amino-2-pyrimidinol 40 is more reactive towards nucleophiles than the C4-amino such that reaction with amine 6 yields N2-substitated-2,4-pyrimidinediamine 42. Subsequent reaction with compound 44, which includes a good leaving group Z, or amine 10 yields a 2,4-pyrimidinediamine according to structural formula (I). Compound 44 may include virtually any leaving group that can be displaced by the C4-amino of N2-substituted-2,4-pyrimidinediamine 42. Suitable leaving groups Z include, but are not limited to, halogens, methanesulfonyloxy (mesyloxy, "OMs"), trifluoromethanesulfonyloxy ("OTf') and p-toluenesulfonyloxy (tosyloxy; "OTs"), benzene sulfonyloxy ("besylate") and metanitro benzene sulfonyloxy ("nosylate"). Other suitable leaving groups will be apparent to those of skill in the art.

[0137] Substituted 4-amino-2-pyrinnidinol starting materials may be obtained commercially or synthesized using standard techniques. Myriad textbook references teaching suitable synthetic methods are provide infra [0138] In stíll anotherexemplary embodiment, the 2,4-pyrimidinediamine compounds can be prepared from 2-chloro-4-aminopyrimidines or 2-amino-4-chloropymidines as illustrated in Scheme (V), below:

Scheme (V) <img file="IS2923B_D0096.tif" /> [0139] InScheme(V), R², R⁴, R⁵, R⁶, L¹, L²andXareasdefinedforScheme(l)andZisasdefinedforScheme(IV). Referring to Scheme (V), 2-amino-4-chloropyrimidine 50 is reacted with amino 10 to yield 4N-substituted-2-pyrimidine-amine 52 which, following reaction with compound 31 or amine 6, yields a 2,4-pyrimidinediamine according to structural formula (I). Alternatively, 2-chloro-4-amino-pyrimidine 54 may be reacted with compound 44 followed by amine 6 to yield a compound according to structural formula (I).

<img file="IS2923B_D0097.tif" />

<img file="IS2923B_D0098.tif" />

[0140] A variety of pyrimidines 50 and 54 suitable for use as starting materials in Scheme (V) are commercially available, including by way of example and not limitation, 2-amino-4,6-dichloropyrimidine (Aldrich #A4860-1; CAS Registry 56-05-3); 2-amino-4-chloro-6-methoxy-pyrimidine (Aldrich #51,864-6; CAS Registry 5734-64-5); 2-amino-4-chloro-

6-methylpyrimidine (Aldrich #12,288-2; CAS Registry 5600-21-5); and 2-amino-4-chloro-6-methylthiopyrimidine (Aldrich #A4600-5; CAS Registry 1005-38-5). Additional pyrimidine starting materials are available from General Intermediates of Canada, Inc., Edmonton, Alberta, CA (www.generalintermediates.com) and/or Interchim, France (www.inter-chim.com), or may be prepared using standard techniques. Myriad textbook references teaching suitable synthetic methods are provided infra.

[0141] Alternatively, 4-chloro-2-pyrimidineamines 50 may be prepared as illustrated in Scheme (Va);

Scheme(Va) ’ <img file="IS2923B_D0099.tif" /> [0142] In Scheme (Va), R⁵ and R⁶ are as previously defined for structural formula (I). In Scheme (Va), dicarbonyl 53 is reacted with guanidine to yield 2-pyrimidineamine 51. Reaction with peracids like m-chloroperbenzoic acid, trifluoroperacetic acid or urea hydrogen peroxide complex yields N-oxide 55, which is then halogenated to give 4-chloro-2-pyrimidineamine 50. The corresponding 4-halo-2-pyrimidineamines may be obtained by using suitable halogenation reagents.

[0143] In yet another exemplary embodiment, the 2,4-pyrimidinediamine compounds can be prepared from substituted or unsubstituted uridines as illustrated in Scheme (VI), below:

<img file="IS2923B_D0100.tif" />

Scheme (VI) <img file="IS2923B_D0101.tif" /> [0144] ln Scheme (VI), R², R⁴, R⁵, R⁶, L¹, L² and X are as previously defined for Scheme (I) and the superscript PG represents a protecting group, as discussed in connection with Scheme (llb). According to Scheme (VI), uridine 60 has a C4 reactive center such that reaction with amine 10 or protected amine 21 yields N4-substituted cytidine 62 or 64, respectively. Acid-catalyzed deprotection of N4-substituted 62 or 64 (when "PG" represents an acid-labile protecting group) yields N4-substituted cytosine 28, which may be subsequently halogenated at the C2-position and reacted with amine 6 to yield a 2,4-pyrimidinediamine according to structural formula (I).

[0145] Cytidines may also be used asstarting materials in an analogous manner, as illustrated in Scheme(VII), below:

<img file="IS2923B_D0102.tif" />

Scheme (VII) <img file="IS2923B_D0103.tif" /> [0146] ln Scheme (VII), R², R⁴, R⁵, R⁶, L¹, L² and X are as previously defined in Scheme (I) and the superscript PG represents a protecting group as discussed above. Referring to Scheme (VII), like uridine 60, cytidine 70 has a C4 reactive center such that reaction with amine 10 or protected amine 21 yields N4-substituted cytidine 62 or 64, respectively. These cytidines 62 and 64 are then treated as previously described for Scheme (VI) to yield a 2,4-pyrimidinediamine according to structural formula (I).

[0147] Although Schemes (VI) and (VII) are exemplified with ribosylnucleosides, skilled artisans will appreciate that the corresponding 2’-deoxyribo and 2’,3’-dideoxyribo nucleosides, as well as nucleosides including sugars or sugar analogs other than ribose, would also work.

[0148] Numerous uridines and cytidines useful as starting materials in Schemes (VI) and (VII) are known in the art, and include, by way of example and not limitation, 5-trifluoromethyl-2’-deoxycytidine (Chem. Sources #ABCR F07669; CAS Registry 66,384-66-5); 5-bromouridine (Chem. Sources lnt’12000; CAS Registry 957-75-5); 5-iodo-2’-deoxyuridine (Aldrich #1-775-6; CAS Registry 54-42-2); 5-fluorouridine (Aldrich #32,937-1; CAS Registry 316-46-1); 5-iodomidine (Aldrich #85,259-7; CAS Registry 1024-99-3); 5-(trifluoromethyl)uridíne (Chem Sources Int'l 2000; CAS Registry 70-00-8)-,5-trifluomethyl-2’-deoxyuridine (Chem. Sources Int’l 2000; CAS Registry 70-00-8). Additional uridines and cytidines that can be used as starting materials in Schemes (VI) and (VII) are available from General Intermediates of Canada, Inc., Edmonton, Alberta, CA (www.generalintermediates.com) and/or Interchim, France (www.interchim.com), or may be prepared using standard techniques. Myriad textbook references teaching suitable synthetic methods are provided infra.

[0149] The 2,4-pyrimidinediamine compounds can also be synthesized from substituted pyrimidines, such as chlorosubstituted pyrimidines, as illustrated in Schemes (VIII) and (IX), below:

<img file="IS2923B_D0104.tif" />

SchemefVin) <img file="IS2923B_D0105.tif" />

Scheme (IX) <img file="IS2923B_D0106.tif" /> [0150] In Schemes (VIII) and (IX), R², R⁴, L¹, L² and R^a are as previously defined for structural formula (I) and "Ar" represents an aryl group. Referring to Scheme (VIII), reaction of 2,4,6-trichloropyrimidine 80 (Aldrich #T5,620-0; CAS#3764-01-0) with amine 6 yields a mixture of three compounds: substituted pyrimidine mono-, di- and triamines81, 82 and 83, which can be separated and isolated using HPLC or other conventional techniques. Mono- and diamines 81 and 82 may be further reacted with amines 6 and/or 10 to yield N2,N4,N6-trisubstituted-2,4,6-,pyrimidinetriamines 84 and 85, respectively.

[0151] N2,N4-bis-substituted-2,4-pyrimidinediamines can be prepared in a manner analogous to Scheme (VIII) by employing 2,4-dichloro-5-methylpyrimidine or 2,4-dichloro-pyrimidine as starting materials. In this instance, the mono-

<img file="IS2923B_D0107.tif" />

<img file="IS2923B_D0108.tif" />

substituted pyrimidineamine corresponding to compound 81 is not obtained. Instead, the reaction proceeds to yield the N2,N4-bis-substituted-2,4-pyrimidinediamine directly.

[0152] Referring to Scheme (IX), 2,4,5,6-tetrachloropyrimidine 90 (Aldrich #24,671-9; CAS#1780-40-1) is reacted with excess amine 6 to yield a mixtureofthree compounds: 91,92, and 93, which can be separated and isolated using HPLC or other conventional techniques. As illustrated, N2,N4-bis-substituted-5,6,-dichloro-2,4-pyrimidinediamine 92 may be further reacted at the C6 halide with, for example a nucleophilic agent 94 to yield compound 95. Alternatively, compound 92 can be converted into N2,N4-bis-subsituted-5-chloro-6-aryl-2,4-pyrimidinediamine 97 via a Suzuki reaction. 2,4-Pyrimidinediamine 95 may be converted to 2,4-pyrimidinediamine 99 by reaction with Bn₃SnH.

[0153] As will be recognized by skilled artisans, 2,4-pyrimidinediamines , synthesized via the exemplary methods described above or by other well-known means, may also be utilized as starting materials and/or intermediates to synthesize additional 2,4-pyrimidinediamine compounds. A specific example is illustrated in Scheme (X), below:

Scheme (X) <img file="IS2923B_D0109.tif" /> [0154] InScheme(X), R⁴, R⁵, R⁶, L²and R^aareaspreviouslydefinedforstucturalformula(l). EachR³’ isindependently an R^a, and may be the same or different from the illustrated R^a. Referring to Scheme (X), carboxylic acid or ester 100 may be converted to amide 104 by reactions with amine 102. In amine 102, R^a' may be the same or different than R^aof acid or ester 100. Similarly, carbonate ester 106 may be converted to carbarmate 108.

[0155] A second specific example is illustrated in Scheme (XI), below:

Scheme (XI) <img file="IS2923B_D0110.tif" />

<img file="IS2923B_D0111.tif" />

<img file="IS2923B_D0112.tif" />

[0156] In Scheme (XI), R⁴, R⁵, R⁶, L² and R^c are as previously defined for structural formula (I). Referring to Scheme (XI), amide 110 or 116 may be converted to amine 114 or 118, respectively, by borane reduction with borane methylsulfide complex 112. Other suitable reactions for synthesizing 2,4-pyrimidinediamine compounds from 2,4-pyrimidinediamine starting materials will be apparent to those of skill in the art.

[0157] Although many of the synthetic schemes discussed above do not illustrate the use of protecting groups, skilled artisans will recognize that in some instances substituents R², R⁴, R⁵, R⁶, L¹ and/or L² may include functional groups requiring protection. The exact identity of the protecting group used will depend upon, among otherthings, the identity of the functional group being protected and the reaction conditions used in the particular synthetic scheme, and will be apparent to those of skill in the art. Guidance for selecting protecting groups and chemistries for their attachment and removal suitable for a particular application can be found, for example, in Greene &amp; Wuts, supra.

[0158] Prodrugs according to structural formula (II) may be prepared by routine modification of the above-described methods. Alternatively, such prodrugs may be prepared by reacting a suitably protected 2,4-pyrimidinediamine of structural formula (I) with a suitable progroup. Conditions for carrying out such reactions and for deprotecting the product to yield a prodrug of formula (II) are well-known.

[0159] Myriad references teaching methods useful for synthesizing pyrimidines generally, as well as starting materials described in Schemes (l)-(IX), are known in the art. For specific guidance, the reader is referred to Brown, D. J., "The Pyrimidines", in The Chemistry of Heterocyclic Compounds, Volume 16 (Weissberger, A., Ed.), 1962, Interscience Publishers, (A Division of John Wiley &amp; Sons), New York ("Brown I"); Brown, D.1., "The Pyrimidines", in The Chemistry of Heterocyclic Compounds, Volume 16, Supplenzent I (Weissberger, A. and T aylor, E. C., Ed.), 1970, Wiley-lnterscience, (ADivisionof JohnWiley&amp;Sons), NewYork(Brown II"); Brown, D. J., "ThePyrimidines", inTheChemistryof Heterocyclic Compounds, Volume 16, Supplement II (Weissberger, A. and Taylor, E. C., Ed.), 1985, An Interscience Publicatíon (John Wiley &amp; Sons), New York ("Brown IIT’); Brown, D. J., "The Pyrimidines" in The Chemistry of Heterocyclic Com-pounds, Volume 52 (Weissberger, A. and Taylor, E. C., Ed.), 1994, John Wiley &amp; Sons, Inc., New York, pp. 1-1509 (Brown IV"); Kenner, G. W. and Todd, A., in Heterocyclic Compounds, Volume 6, (Elderfield, R C., Ed.), 1957, John Wiley, New York, Chapter 7 (pyrimidines); Paquette, L. A., Principles of Modem Heterocyclic Chenzistry, 1968, W. A. Benjamin, Inc., NewYork, pp. 1 -401 (uracil synthesis pp. 313,315; pyrimidine synthesis pp. 313-316; amino pyrimidine synthesis pp. 315); Joule, J. A., Mills, Kand Smith, G. F., Heterocyclic Chemistry, 3rd Edition, 1995, Chapman and Hall, London, UK, pp. 1-516; Vorbriiggen, H. and Ruh-Pohlenz, C., Handbook of Nucleoside Synthesis, John Wiley &amp; Sons, New York, 2001, pp. 1-631 (protection of pyrimidines by acylation pp. 90-91; silylation of pyrimidines pp. 91-93); Joule, J. A., Mills, K. and Smith, G. F., Heterocyclic Chemistry, 4th Edition, 2000, Blackwell Science, Ltd, Oxford, UK, pp. 1 -589; and Comprehensive Organic Synthesis, Volumes 1-9 (Trost, B. M. and Fleming, I., Ed.), 1991, Pergamon Press, Oxford, UK.

6.4 Inhibition of Fc Receptor Signal Cascades [0160] Active 2,4-pyrimidinediamine compounds of The invention inhibit Fc receptor signalling cascades that lead to, among other things, degranulation of cells. As a specific example, the compounds inhibit the Fce-RI and/or FcyRI signal cascades that lead to degranulation of immune cells such as neutrophil, eosinophil, mast and/or basophil cells. Both mast and basophil cells play a central role in allergen-induced disorders, including, for example, allergic rhinítis and asthma. Referring to FIG. 1, upon exposure allergens, which may be, among otherthings, pollen or parasites, allergenspecific IgE antibodies are synthesized by B-cells activated by IL-4 (or IL-13) and other messengers to switch to IgE class specific antibody synthesis. These allergen-specific IgEs bind to the high affinity FœRI. Upon binding of antigen, the FœR1-bound IgEs are cross-linked and the IgE receptor signal transduction pathway is activated, which leads to degranulation ofthe cells and consequent release and/or synthesis of a host of chemical mediators, including histamine, proteases (e.g., tryptase and chymase), lipid mediators such as leukotrienes (e.g., LTC4), platelet-activating factor (PAF) and prostaglandins (e.g., PGD2) and a series of cytokines, including TNF-α, IL-4, iL-13, IL-5, IL-6, IL-8, GMCSF, VEGF and TGF-β. The release and/or synthesis of these mediators from mast and/or basophil cells accounts for the early and late stage responses induced by allergens, and is directly linked to downstream events that lead to a sustained inflammatory state.

[0161] The molecular events in the FœRI signal transduction pathway that lead to release of preformed mediators via degranulation and release and/or synthesis of other chemical mediators are well-known and are illustrated in FIG. 2. Referring to FIG. 2, the FœRI is a heterotetrameric receptor composed of an IgE-binding alpha-subunit, a beta subunit, and two gamma subunits (gamma homodimer). Cross-linking of FceRI-bound IgE by multivalent binding agents (including, for example IgE-specific allergens or anti-lgE antibodies or fragments) induces the rapid association and activation of the Src-related kinase Lyn. Lyn phosphorylates immunoreceptor tyrosine-based activation motifs (ITAMS) on the intracellular beta and gamma subunits, which leads to the recruitment of additional Lyn to the beta subunit and Syk kinase to the gamma homodimer. These receptor-associated kinases, which are activated by intra- and intermolecular phos-phorylation, phosphorylate other components of the pathway, such as the Btk kinase, LAT, and phospholipase C-gamma

PLC-gamma). Activated PLC-gamma initiates pathways that lead to protein kinase C activation and Ca²⁺ mobilization, both of which are required for degranulation. FceRI cross-linking also activates the three major classes of mitogen activated protein (MAP) kinases, i.e. ERK1/2, JNK1/2, and p38. Activation of these pathways is important in the transcriptional regulation of proinflammatory mediators, such as TNF-α and IL-6, as well as the lipid mediator leukotriene CA (LTC4).

[0162] Although not illustrated, the FcyRI signaling cascade is believed to share some common elements with the FceRI signaling cascade. Importantly, like FœRI, the FcyRI includes a gamma homodimer that is phosphorylated and recruits Syk, and like FceRI, activation ofthe FcyRI signaling cascade leadsto, among otherthings, degranulation. Other Fc receptors that share the gamma homodimer, and which can be regulated by the active 2,4-pynnndmediamine compounds include, but are not limited to, FcaRI and FcyRIII.

[0163] The ability of the 2.4-pyrimidinediamine compounds of The invention to inhibit Fc receptor signaling cascades may be simply determined or confirmed in in vitro assays. Suitable assays for confirming inhition of FceRI-mediated degranulation are provided in the Examples section. In one typical assay, cells capable of undergoing FœRI mediated degranulation, such as mast or basophil cells, are first grown in the presence of IL-4, Stem Cell Factor (SCF), IL-6 and IgB to increase expression of the PceRI, exposed to a 2,4-pyrimidinediamine test compound of The invention and stimulated with anfi-lgE antibodies (or, alternatively, an IgE-specifie allergen). Following incubation, the amount of a chemical mediator or other chemical agent released and/or synthesized as a consequence of activating the FceRI signaling cascade may be quantified using standard techniques and compared to the amount of the mediator or agent released from control cells (í.e., cells that are stimulated but that are not exposed to test compound). The concentration of test compound that yields a 50% reduction in the quantity of the mediator or agent measured as compared to control cells is me IC₅₀ of the test the origin of the mast or basophil cells used in the assay will depend, in part, on the desired use for the compounds and will be apparent to those of skill in the art For example, if the compounds will be used to treat or prevent a particular disease in humans, a convenient source of mast or basophil cells is a human or other animal which constitutes an accepted or known clinical model for the particular disease. Thus, depending upon the particular application, the mast or basophil cells may be derived from a wide variety of animal sources, raging from, for example, lower mammals such as mice and rats, to dogs, sheep and other mammals commonly employed in clinical testing, to higher mammals such as monkeys, chimpanzees and apes, to humans. Specific examples of cells suitable for carrying out the in vitro assays include, but are not limited to, rodent or human basophil cells, rat basophil leukemia cell lines, primary mouse mast cells (such as bone marrow-derived mouse mast cells "BMMC") and primary human mast cells isolated from cord blood ("CHMC") or other tissues such as lung. Methods for isolating and culturing these cell types are well-known or are provided in the Examples section (see, e.g., Demo et al.,1999, Cytometry 36(4):340-348 and copending application Serial No. 10/053,355, filed November 8, 2001 . Of course, other types of immune cells that degranulate upon activation of the FceRI signaling cascade may also be used, including, for example, eosinophils.

[0164] As will be recognized by skilled artisans, the mediator or agent quantified is not critical. The only requirement is that it be a mediator or agent released and/or synthesized as a consequence of initiating or activating the Fc receptor signaling cascade. For example, referring to FIG. 1, activation of the FœRI signaling cascade in mast and/or basophil cells leads to numerous downstream events. For example, activation of the FceRI signal cascade leads to the immediate release (i.e., within 1-3 min. following receptor activation) of a variety of preformed chemical mediators and agents via degranulation. Thus, in one embodiment, the mediator or agent quantified may be specific to granules (/'.e., present in granules but not in the cell cytoplasm generally). Examples of granule-specific mediators or agents that can be quantified to determine and/or confirm the activity of a 2,4-pyrimidinediamine compound of The invention include, but are not limited to, granule-specific enzymes such as hexosaminidase and tryptase and granule-specific components such as histamine and serotonin. Assays for quantifying such factors are well-known, and in many instances are commercially available. Forexample, tryptase and/or hexosaminidase release may be quantified by incubating the cells with cleavable substrates thatfluoresce upon cleavage and quantifying the amount of fluorescence produced using conventional techniques. Such cleavable fluorogenic substrates are commercially available. For example, the fluorogenic substrates Z-Gly-Pro-Arg-AMC (Z=benzyloxycarbonyl; AMC=7-amino-4-methylcoumarin; BIOMOL Research Laboratories, Inc., Plymouth Meet-ing, PA 19462, Catalog No. P-142) and Z-Ala-Lys-Arg-AMC (Enzyme Systems Products, a division of ICN Biomedicals, Inc., Livermore, CA 94550, Catalog No. AMC-246) can be used to quantify the amount of tryptase released. The fluor-ogenic substrate 4-methylumbelliferyl-N-acetyl-8-D-glucosaminide (Sigma, St. Louis, MO, Catalog #69585) can be used to quantify the amount of hexosaminidase released. Histamine release may be quantified using a commercially available enzyme-linked immunosorbentassay (ELISA) such as Immunotech histamine ELISAassay #IM2015 (Beckman-Coulter, Inc.). Specific methods of quantifying the release of tryptase, hexosaminidase and histamine are provided in the Examples section. Any of these assays may be used to determine or confirm the activity of the 2,4-pyrimidinediamine compounds of The invention.

[0165] Referring again to FIG. 1, degranulation is only one of several responses initiated by the FceRI signaling cascade. In addition, activation of this signaling pathway leads to the de novo synthesis and release of cytokines and chemokines such as IL-4, IL-5, IL-6, TNF-α, IL-13 and MIP1-a), and release of lipid mediators such as leukotrienes (e.g., LTC4), platelet activating factor (PAF) and prostaglandins. Accordingly, the 2,4-pyrimidinediamine compounds of The invention may also be assessed for activity by quantifying the amount of one or more of these mediators released and/or synthesized by activated cells.

[0166] Unlike the granule-specific components discussed above, these "late stage" mediators are not released immediately following activation of the FceRI signaling cascade. Accordingly, when quantifying these late stage mediators, care should be taken to insure that the activated cell culture is incubated for a time sufficient to result in the synthesis (if necessary) and release of the mediator being quantified. Generally, PAF and lipid mediators such as leukotriene C4 are released 3-30 min. following FceRI activation. The cytokines and other late stage mediators are released approx. 4-8 hrs. following FceRI activation. Incubation times suitable for a specific mediator will be apparent to those of skill in the art. Specific guidance and assays are provided in the Examples section.

[0167] The amount of a particular late stage mediator released may be quantified using any standard technique. In one embodiment, the amount(s) may be quantified using ELISA assays. ELISA assay kits suitable for quantifying the amount of TNFa, IL-4, IL-5, IL-6 and/or IL-13 released are available from, for example, Biosource International, Inc., Camarillo, CA 93012 (see, e.g., Catalog Nos. KHC3011, KHC0042, KHC0052, KHC0061 and KHC0132). ELISAassay kits suitable for quantifying the amount of leukotriene C4 (LTC4) released from cells are available from Cayman Chemical Co., Ann Arbor, Ml 48108 (see, e.g., Catalog No. 520211).

[0168] Typically, active 2,4-pyrimidinediamine compounds of The invention will exhibit IC₅₀s with respect to FceRI-mediated degranulation and/or mediator release or synthesis of about 20 μΜ or lower, as measured in an in vitro assay, such as one of the in vitro assays described above or in the Examples section. Of course, skilled artisans will appreciate that compounds which exhibit lower IC₅₀s, for example on the order of 10 μΜ, 1 μΜ, 100 nM, 10 nM, 1 ηΜ, or even lower, are particularly useful.

[0169] Skilled artisans will also appreciate that the various mediators discussed above may induce different adverse effects or exhibit different potencies with respect to the same adverse effect. For example, the lipid mediator LTC4 is a potent vasoconstrictor- it is approximately 10OO-fold more potent at inducing vasoconstriction than histamine. As another example, in addition to mediating atopic or Type I hypersensitivity reactions, cytokines can also cause tissue remodeling and cell proliferation. Thus, although compounds that inhibit release and/or synthesis of any one of the previously discussed chemical mediators are useful, skilled artisans will appreciate that compounds which inhibit the release and/or synthesis of a plurality, or even all, of the previously described mediators find particular use, as such compounds are useful for ameliorating or avoiding altogether a plurality, or even all, of the adverse effects induced by the particular mediators. For example, compounds which inhibit the release of all three types of mediators—granule-specifíc, lipid and cytokine—are useful for treating or preventing immediate Type I hypersensitivity reactions as well as the chronic symptoms associated therewith.

[0170] Compounds of The invention capable of inhibiting the release of more than one type of mediator (e.g., granulespecific or late stage) may be identified by determining the IC₅₀ with respect to a mediator representative of each class using the various in vitro assays described above (or other equivalent in vitro assays). Compounds of The invention which are capable of inhibiting the release of more than one mediator type will typically exhibit an IC₅₀ for each mediator type tested of lessthan about 20 μΜ. Forexample, a compound which exhibitsan IC₅₀ of 1 μΜ with respectto histamine release (IC₅₀^histamine) and an IC50 of 1 nM with respect to leukotriene LTC4 synthesis and/or release (IC50^LTC4) inhibits both immediate (granule-specific) and late stage mediator release. As another specific example, a compound that exhibits an IC50^tryP^tasa of 10 μΜ, an IC50 ^LTC4 of 1 μΜ and an IC50IL-4 of 1 μΜ inhibits immediate (granule-specific), lipid and cytokine mediator release. Although the above specific examples utilize the IC₅₀s of one representative mediator of each class, skilled artisans will appreciate that the IC₅₀s of a plurality, or even all, mediators comprising one or more of the classes may be obtained. The quantity(ies) and identity(ies) of mediators for which IC₅₀ data should be ascertained for a particular compound and application will be apparent to those of skill in the art [0171] Similarassays may be utilized to confirm inhibition of signal transduction cascades initiated by other Fc recep-tors, such as FcaRI, FcyRI and/or FcyRIII signaling, with routine modification. For example, the ability of the compounds to inhibit FcyRI signal transductíon may be confirmed in assays similarto those described above, with the exception that the FcyRI signaling cascade is activated, for example by incubating the cells with IgG and an IgG-specific allergen or antibody, instead of IgE and an IgE-specific allergen or antibody. Suitable cell types, activating agents and agents to quantifý to confirm inhibition of other Fc receptors, such as Fc receptors that comprise a gamma homodimer, will be apparent to those of skill in the art.

[0172] One particularly useful class of compounds includes those 2,4-pyrimidinediamine compounds that inhibit the release of immediate granule-specific mediators and late stage mediators with approximately equivalent IC₅₀s. By approximately equivalent is meant that the IC₅₀s for each mediator type are within about a 10-fold range of one another. Another particularly useful class of compounds includes those 2,4-pyrimidinediamine compounds that inhibit the release of immediate granule-specific mediators, lipid mediators and cytokine mediators with approximately equivalent IC_60S-In a specific embodiment, such compounds inhibit the release of the following mediators with approximately equivalent IC₅₀s: histamine, tryptase, hexosaminidase, IL-4, IL-5, IL-6, IL-13, TNFot and LTC4. Such compounds are particularly useful for, among other things, ameliorating or avoiding altogether both the early and late stage responses associated with atopic or immediate Type I hypersensitivity reactions.

[0173] Ideally, the ability to inhibit the release of all desired types of mediators will reside in a single compound. However, mixtures of compounds can also be identified that achieve the same result. For example, a first compound which inhibits the release of granule specific mediators may be used in combination with a second compound which inhibits the release and/or synthesis of cytokine mediators.

[0174] In addition to the FceRI or FcyRI degranulation pathways discussed above, degranulation of mast and/or basophil cells can be induced by other agents. For example, ionomycin, a calcium ionophore that bypasses the early FœRI or FcyRI signal transduction machinery of the cell, directly induces a calcium flux that triggers degranulation. Referring again to FIG. 2, activated PLCy initiates pathways that lead to, among other things, calcium ion mobilization and subsequent degranulation. As illustrated, this Ca²⁺ mobilization is triggered late in the FœRI signal transduction pathway. As mentioned above, and as illustrated in FIG. 3, ionomycin directly induces Ca²⁺ mobilization and a Ca²⁺ flux that leads to degranulation. Other ionophores that induce degranulation in this manner include A23187. The ability of granulation-inducing ionophores such as ionomycin to bypass the early stages of the FœRI and/or FcyRI signaling cascades may be used as a counter screen to identify active compounds of The invention that specifically exert their degranulation-inhibitory activity by blocking or inh ibiting the early FœRI or FcyRI signaling cascades, as discussed above. Compounds which specifically inhibit such early FœRI or FcyRI-mediated degranulation inhibit not only degranulation and subsequent rapid release of histamine, tryptase and other granule contents, but also inhibit the pro-inflammatory activation pathways causing the release of TNFa, IL-4, IL-13 and the lipid mediators such as LTC4. Thus, compounds which specifically inhibit such early FœRI and/or FcyRI-mediated degranulation block or inhibit not only acute atopic or Type I hypersensitivity reactions, but also late responses involving multiple inflammatory mediators.

[0175] Compounds of The invention that specifically inhibit early FceRI and/or FcryRI-mediated degranulation are those compounds that inhibit FceRI and/or FcyRI-mediated degranulation (for example, have an IC₅₀ of less than about 20 μΜ with respect to the release of a granule-specific mediator or component as measured in an in vitro assay with cells stimulated with an IgE or IgG binding agent) but that do not appreciably inhibit ionophore-induced degranulation. In one embodiment, compounds are considered to not appreciably inhibit ionophore-induced degranulation if they exhibit an IC₅₀ of ionophore-induced degranulation of greater than about 20 μΜ, as measured in an /n vitro assay. Of course, active compounds that exhibit even higher IC₅₀s of ionophore-induced degranulation, or that do not inhibit ionophore-induced degranulation at all, are particularly useful. In another embodiment, compounds are considered to not appreciably inhibit ionophore-induced degranulation if they exhibit a greater than 10-fold difference in their IC₅₀s of FceRI and/or FcyRI-mediated degranulation and ionophore-induced degranulation, as measured in an in vitro assay. Assays suitable for determining the IC₅₀ of ionophore-induced degranulation include any of the previously-described degranulation assays, with the modification that the cells are stimulated or activated with a degranulation-inducing calcium ionophore such as ionomycin or A23187 (A.G. Scientific, San Diego, CA) instead of anti-lgE antibodies oran IgE-specific allergen. Specific assays for assessing the ability of a particular 2,4-pyrimidinediamine compound of The invention to inhibit ionophore-induced degranulation are provided in the Examples section.

[0176] As will be recognized by skilled artisans, compounds which exhibit a high degree of selecti vity of FceRI-mediated degranulation find particular use, as such compounds selectively target the FœRI cascade and do not interfere with other degranulation mechanisms. Similarly, compounds which exhibit a high degree of selectivity of Fc-yRI-mediated degranulation find particular use, as such compounds selectively target the FcyRI cascade and do not interfere with other degranulation mechanisms. Compounds which exhibit a high degree of selectivity are generally 10-fold or more selective for FœRI- or FcyRI -mediated degranulation over ionophore-induced degranulation, such as ionomycin-induced degranulation.

[0177] Biochemical and other data confirm that the 2,4-pyrimidinediamine compounds described herein are potent inhibitors of Syk kinase activity. For example, in experiments with an isolated Syk kinase, of twenty four 2,4-pyrimidin-ediamine compounds tested, all but two inhibited the Syk kinase catalyzed phosphorylation of a peptide substrate with IC50s in the submicromolar range. The remaining compounds inhibited phosphorylation in the micromolar range. In addition, of sixteen compounds tested in an in vitro assay with mast cells, all inhibited phosphorylation of Syk kinase substrates (e.g., PLC-gammal, LAT) and proteins downstream of Syk kinase (e.g., JNK, p38, Erk1/2 and PKB, when tested), but not proteins upstream of Syk kinase in the cascade (e.g., Lyn). Phosphorylation of Lyn substrates was not inhibited by the 2,4-pyrimtdinediamine compounds tested. Moreover, for the following compounds, a high correlation was observed between their inhibition of Syk kinase activity in biochemical assays (IC₅₀s in the range of 3 to 1850 nM) and their inhibition of FceR1-mediated degranulation in mast cells (IC₅₀s in the range of 30 to 1650 nM): R950373, R950368, R921302, R945371, R945370, R945369, R945365, R921304, R945140, R945071, R940358, R940353,

R940352, R940351, R940350, R940347, R921303, R940338, R940323, R940290, R940277, R940276, R940275,

R940269, R940255, R935393, R935372, R935366, R935310, R935309, R935307, R935304, R935302, R935293,

R935237, R935198, R935196, R935194, R935193, R935191, R935190, R935138, R927050, R926968, R926956,

R926931, R926891, R926839, R926834, R926816, R926813, R926791, R926782, R926780, R926757, R926753,

R926745, R926715, R926508, R926505, R926502, R926501, R926500, R921218, R921147, R920410, R909268, R921219, R908712, R908702.

[0178] Accordingly, the activity of the 2,4-pyrimidinediamine compounds of The invention may also be confirmed in biochemical or cellular assays of Syk kinase activity. Referring again to FIG. 2, in the FceRI signaling cascade in mast and/or basophil cells, Syk kinase phosphorylates LAT and PLC-gammal, which leads to, among otherthings, degranulation. Any of these activities may be used to confirm the activity of the 2,4-pyrimidinediamine compounds of The invention. In one embodiment, the activity is confirmed by contacting an isolated Syk kinase, or an active fragment thereof with a 2,4-pyrimidinediamine compound in the presence of a Syk kinase substrate (e.g., a synthetic peptide or a protein that is known to be phophorylated by Syk in a signaling cascade) and assessing whether the Syk kinase phosphorylated the substrate. Alternatively, the assay may be carried out with cells that express a Syk kinase. The cells may express the Syk kinase endogenously or they may be engineered to express a recombinant Syk kinase. The cells may optionally also express the Syk kinase substrate. Cells suitable for performing such confirmation assays, as well as methods of engineering suitable cells will be apparent to those of skill in the art. Specific examples of biochemical and cellular assays suitable for confirming the activity of the 2,4-pyrimidinediamine compounds are provided in the Examples section.

[0179] Generally, compounds that are Syk kinase inhibitors will exhibit an IC₅₀ with respect to a Syk kinase activity, such as the ability of Syk kinase to phosphorylate a synthetic or endogenous substrate, in an /n vitro or cellular assay in the range of about 20 μΜ or less. Skilled artisans will appreciate that compounds that exhibit lower IC50s, such as in the range of 10 μΜ, 1μΜ, 100 nM, 10 nM, 1 ηΜ, oreven lower, are particularly useful.

6.5 Uses and Compositions [0180] As previously discussed, the active compounds of The invention inhibit Fc receptorsignaling cascades, especially those Fc receptors including a gamma homodimer, such as the FceRI and/or FcyRI signaling cascades, that lead to, among other things, the release and/or synthesis of chemical mediators from cells, either via degranulation or other processes. As also discussed, the active compounds are also potent inhibitors of Syk kinase. As a consequence of these activities, the active compounds of The invention may be used in a variety of in vitro, in vivo and ex vivo contexts to regulate or inhibit Syk kinase, signaling cascades in which Syk kinase plays a role, Fc receptor signaling cascades, and the biological responses effected by such signaling cascades. For example, in one embodiment, the compounds may be used to inhibit Syk kinase, either in vitro or in vivo, in virtually any cell type expressing Syk kinase. They may also be used to regulate signal transduction cascades in which Syk kinase plays a role. Such Syk-dependent signal transduction cascades include, but are not limited to, the FœRI, FcyRI, FcyRIII, BCR and integrin signal transduction cascades. The compounds may also be used in vitro or in vivo to regulate, and in particular inhibit, cellular or biological responses effected by such Syk-dependent signal transduction cascades. Such cellularor biological responses include, but are not limited to, respiratory burst, cellular adhesion, cellular degranulation, cell spreading, cell migration, cell aggregation, phagcytosis, cytokine synthesis and release, cell maturation and Ca²⁺ flux. Importantly, the compounds may be used to inhibit Syk kinase in vivo as a therapeutic approach towards the treatment or prevention of diseases mediated, either wholly or in part, by a Syk kinase activity. Non-limiting examples of Syk kinase mediated diseases that may be treated or prevented with the compounds are those discussed in more detail, below.

[0181] In another embodiment, the active compounds may be used to regulate or inhibit the Fc receptor signaling cascades and/or FceRI- and/or FcyRI-mediated degranulation as a therapeutic approach towards the treatment or prevention of diseases characterized by, caused by and/or associated with the release or synthesis of chemical mediators of such Fc receptor signaling cascades or degranulation. Such treatments may be administered to animals in veterinary contexts or to humans. Diseases that are characterized by, caused by or associated with such mediator release, synthesis or degranulation, and that can therefore be treated or prevented with the active compounds include, by way of example and notlimitation, atopy oranaphylactichypersensitivityorallergicreactions, allergies (e.g., allergicconjunctivitis, allergic rhinitis, atopic asthma, atopic dermatitis and food allergies), low grade scarring (e.g., of scleroderma, increased fibrosis, keloids, post-surgical scars, pulmonary fibrosis, vascular spasms, migraine, reperfusion injury and post myocardial infarction), diseases associated with tissue destruction (e.g., of COPD, cardiobronchitis and post myocardial infarction), diseases associated with tissue inflammation (e.g., irritable bowel syndrome, spastic colon and inflammatory bowel disease), inflammation and scarring.

[0182] In addition to the myriad diseases discussed above, cellular and animal empirical data confirm that the 2,4-pyrimidinediamine compounds described herein are also useful for the treatment or prevention of autoimmune diseases, as well as the various symptoms associated with such diseases. The types of autoimmune diseases that may be treated or prevented with the 2,4-pyrimidinediamine compounds generally include those disorders involving tissue injury that occurs as a result of a humoral and/or cell-mediated response to immunogens or antigens of endogenous and/or exogenous origin. Such diseases are frequently referred to as diseases involving the nonanaphylactic (/.e., Type II, Type III and/or Type IV) hypersensitivity reactions.

[0183] Asdiscussed previously, Type I hypersensitivity reactions generally resultfrom the release of pharmacologically active substances, such as histamine, from mast and/or basophil cells following contact with a specific exogenous antigen. As mentioned above, such Type I reactions play a role in numerous diseases, including allergic asthma, allergic rhinitis, etc.

[0184] Type II hypersensitivity reactions (also referred to as cytotoxic, cytolytic complement-dependent or cell-stimulating hypersensitivity reactions) result when immunoglobulins react with antigenic components of cells or tissue, or with an antigen or hapten that has become intimately coupled to cells or tissue. Diseases that are commonly associated with Type II hypersensitivity reactions include, but are not limited, to autoimmune hemolytic anemia, erythroblastosis fetalis and Goodpasture’s disease.

[0185] Type III hypersensitivity reactions, (also referred to as toxic complex, soluble complex, or immune complex hypersensitivity reactions) result from the deposition of soluble circulating antigen-immunoglobulin complexes in vessels or in tissues, with accompanying acute inflammatory reactions at the site of immune complex deposition. Non-limiting examples of prototypical Type III reaction diseases include the Arthus reaction, rheumatoid arthritis, serum sickness, systemic lupus erythematosis, certain types of glomerulonephrítis, multiple sclerosis and bullous pemphingoid.

[0186] Type IV hypersensitivity reactions (frequently called cellular, cell-mediated, delayed, or tuberculin-type hypersensitivity reactions) are caused by sensitized T-lymphocytes which result from contact with a specific antigen. Nonlimiting examples of diseases cited as involving Type IV reactions are contact dermatitis and allograft rejection.

[0187] Autoimmune diseases associated with any of the above nonanaphylactic hypersensitivity reactions may be treated or prevented with the 2,4-pyrimidinediamine compounds of The invention. In particular, the methods may be used to treat or prevent those autoimmune diseases frequently characterized as single organ or single cell-type autoimmune disorders including, but not limited to: Hashimoto’s thyroiditis, autoimmune hemolytic anemia, autoimmune atrophic gastritis of pernicious anemia, autoimmune encephalomyelitis, autoimmune orchitis, Goodpasture’s disease, autoimmune thrombocytopenia, sympathetic ophthalmia, myasthenia gravis, Graves’ disease, primary biliary cirrhosis, chronic aggressive hepatitis, ulcerative colitis and membranous glomerulopathy, as well as those autoimmune diseases frequently characterized as involving systemic autoimmune disorder, which include but are not limited to: systemic lupus erythematosis, rheumatoid arthritis, Sjogren’s syndrome, Reiter’s syndrome, polymyositis-dermatomyositis, systemic sclerosis, polyarteritis nodosa, multiple sclerosis and bullous pemphigoid.

[0188] It will be appreciated by skilled artisans that many of the above-listed autoimmune diseases are associated with severe symptoms, the amelioration of which provides significant therapeutic benefit even in instances where the underlying autoimmune disease may not be ameliorated. Many of these symptoms, as well as their underlying disease states, result as a consequence of activating the FcyR signaling cascade in monocyte cells. As the 2,4-pyrimidinediamine compounds described herein are potent inhibitors of such FcyR signaling in monocytes and other cells, the methods find use in the treatment and/or prevention of myriad adverse symptoms associated with the above-listed autoimmune diseases.

[0189] As aspecifícexample, rheumatoid arthritis (RA) typically results in swelling, pain, loss of motion and tenderness of target joints throughout the body. RA is characterized by chronically inflamed synovium that is densely crowded with lymphocytes. The synovial membrane, which is typically one cell layer thick, becomes intensely cellular and assumes aforrn similarto lymphoid tissue, including dentritic cells, T-, B- and NKcells, macrophages and clusters of plasma cells. This process, as well as a plethora of immunopathological mechanisms including the formation of antigen-immunoglobulin complexes, eventually result in destruction of the integrity of the joint, resulting in deformity, permanent loss of function and/or bone erosion at or near the joint. The methods may be used to treat or ameliorate any one, several or all of these symptoms of RA. Thus, in the context of RA, the methods are considered to provide therapeutic benefit (discussed more generally, infrá) when a reduction or amelioration of any of the symptoms commonly associated with RA is achieved, regardless of whether the treatment results in a concomitant treatment of the underlying RA and/or a reduction in the amount of circulating rheumatoid factor ("RF").

[0190] As another specific example, systemic lupus erythematosis ("SLE") is typically associated with symptoms such as fever, joint pain (arthralgias), arthritis, and serositis (pleurisy or pericarditis). In the context of SLE, the methods are considered to provide therapeutic benefit when a reduction or amelioration of any of the symptoms commonly associated with SLE are achieved, regardless of whether the treatment results in a concomitant treatment of the underlying SLE. [0191] As another specific example, multiple sclerosis ("MS") cripples the patient by disturbing visual acuity; stimulating double vision; disturbing motor functions affecting walking and use of the hands; producing bowel and bladder inconti-nence; spasticity; and sensory deficits (touch, pain and temperature sensitivity). In the context of MS, the methods are considered to provide therapeutic benefit when an improvement or a reduction in the progression of any one or more of the crippling effects commonly associated with MS is achieved, regardless of whether the treatment results in a concomitant treatment of the underlying MS.

[0192] When used to treat or prevent such diseases, the active compounds may be administered singly, as mixtures of one or more active compounds or in mixture or combination with other agents useful for treating such diseases and/or the symptoms associated with such diseases. The active compounds may also be administered in mixture or in combination with agents useful to treat other disorders or maladies, such as steroids, membrane stablizers, SLO inhibitors, leukotriene synthesis and receptor inhibitors, inhibitors of IgE isotype switching or IgE synthesis, IgG isotype switching or IgG synthesis, β-agonists, tryptase inhibitors, aspirin, COX inhibitors, methotrexate, anti-TNF drugs, retoxin, PD4 inhi bitors, p38 inhibitors, PDE4 inhibitors, and antihistamines, to name afew. The active compounds may be administered perse in the form of prodrugs or as pharmaceutical compositions, comprising an active compound or prodrug.

[0193] Pharmaceutical compositions comprising the active compounds of The invention (or prodrugs thereof) may be manufactured by means of conventional mixing, dissolving, granulating, dragee-making levigating, emulsifying, encap-sulating, entrapping or lyophilization processes. The compositions may be formulated in conventional manner using one or more physiologically acceptable carriers, diluents, excipients or auxiliaries which facilitate processing of the active compounds into preparations which can be used pharmaceutically.

[0194] The active compound or prodrug may be formulated in the pharmaceutical compositions perse, or in the form of a hydrate, solvate, N-oxide or pharmaceutically acceptable salt, as previously described. Typically, such salts are more soluble in aqueous solutions than the corresponding free acids and bases, but salts having lower solubility than the corresponding free acids and bases may also be formed.

[0195] Pharmaceutical compositions may take a form suitable for virtually any mode of administration, including, for example, topical, ocular, oral, buccal, systemic, nasal, injection, transdermal, rectal, vaginal, etc., or a form suitable for administration by inhalation or insufflation.

[0196] Fortopicaladministration,theactivecompound(s)orprodrug(s)maybeformulatedassolutions, gels, ointments, creams, suspensions, etc. as are well-known in the art.

[0197] Systemicformulations include those designed for administration by injection, e.g., subcutaneous, intravenous, intramuscular, intrathecal or intraperitoneal injection, as well as those designed for transdermal, transmucosal oral or pulmonary administration.

[0198] Useful injectable preparations include sterile suspensions, solutions or emulsions of the active compound(s) in aqueous or oily vehicles. The compositions may also contain formulating agents, such as suspending, stabilizing and/or dispersing agent The formulations for injection may be presented in unit dosage form, e.g., in ampules or in multidose containers, and may contain added preservatives.

[0199] Alternatively, the injectable formulation may be provided in powder form for reconstitution with a suitable vehicle, including but not limited to sterile pyrogen free water, buffer, dextrose solution, etc., before use. To this end, the active compound(s) may be dried by any art-known technique, such as lyophilization, and reconstituted priorto use.

[0200] For transmucosal administration, penetrants appropriate to the barrier to be permeated are used in the formulation. Such penetrants are known in the art [0201] For oral administration, the pharmaceutical compositions may take the form of, for example, lozenges, tablets or capsules prepared by conventional means with pharmaceutically acceptable excipients such as binding agents (e.g., pregelatinised maize starch, polyvinylpyrrolidone or hydroxypropyl methylcellulose); fillers (e.g., lactose, microcrystalline cellulose orcalcium hydrogen phosphate); lubricants (e.g., magnesium stearate, talcorsilica); disintegrants (e.g., potato starch orsodium starch glycolate); or wetting agents (e.g., sodium lauryl sulfate). The tablets may be coated by methods well known in the art with, for example, sugars, films or enteric coatings. Compounds which are particularly suitable for oral administration include Compounds R940350, R935372, R935193, R927050 and R935391.

[0202] Liquid preparations for oral administration may take the form of, for example, elixirs, solutions, syrups or sus-pensions, or they may be presented as a dry product for constitution with water or other suitable vehicle before use. Such liquid preparations may be prepared by conventional means with pharmaceutically acceptable additives such as suspending agents (e.g., sorbitol syrup, cellulose derivatives or hydrogenated edible fats); emulsifying agents (e.g., lecithin or acacia); non-aqueous vehicles (e.g., almond oil, oily esters, ethyl alcohol, cremophore™ or fractionated vegetable oils); and preservatives (e.g., methyl or propyl-p-hydroxybenzoates or sorbic acid). The preparations may also contain buffer salts, preservatives, flavoring, coloring and sweetening agents as appropriate.

[0203] Preparationsfor oral administration may be suitably formulated to give controlled release of the active compound or prodrug, as is well known..

[0204] For buccal administration, the compositions may take the form of tablets or lozenges formulated in conventional manner.

[0205] For rectal and vaginal routes of administration, the active compound(s) may be formulated as solutions (for retention enemas) suppositories or ointments containing conventional suppository bases such as cocoa butter or other glycerides.

[0206] For nasal administration or administration by inhalation or insufflation, the active compound(s) or prodrug(s) can be conveniently delivered in the form of an aerosol spray from pressurized packs or a nebulizer with the use of a suitable propellant, e.g., dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, fluorocarbons, carbon dioxide or other suitable gas. In the case of a pressurized aerosol, the dosage unit may be determined by providing a valve to deliver a metered amount Capsules and cartridges for use in an inhaler or insufflator (for example capsules and cartridges comprised of geíatin) may be formulated containing a powder mix of the compound and a suitable powder base such as lactose or starch.

[0207] A specific example of an aqueous suspension formulation suitable for nasal administration using commercially-available nasal spray devices includes the following ingredients: active compound or prodrug (0.5-20 mg/ml); benzalkonium chloride (0.1-0.2 mg/mL); polysorbate 80 (TWEEN® 80; 0.5-5 mg/ml); carboxymethylcellulose sodium or microcrystalline cellulose (1-15 mg/ml); phenylethanol (1-4 mg/ml); and dextrose (20-50 mg/ml). The pH of the final suspension can be adjusted to range from about pH5 to pH7, with a pH of about pH 5.5 being typical.

[0208] Another specific example of an aqueous suspension suitablefor administration of the compounds via inhalation, and in particular for such administration of Compound R921218, contains 1-20 mg/mL Compound or prodrug, 0.1-1% (v/v) Polysorbate 80 (TWEEN®80), 50 mM citrate and/or 0.9% sodium chloride.

[0209] For ocular administration, the active compound(s) or prodrug(s) may be formulated as a solution, emulsion, suspension, etc. suitable for administration to the eye. A variety of vehicles suitable for adminístering compounds to the eye are known in the art. Specific non-limiting examples are described in U.S. Patent No. 6,261,547; U.S. Patent No. 6,197,934; U.S. PatentNo. 6,056,950; U.S. Patent No. 5,800,807; U.S. PatentNo. 5,776,445; U.S. PatentNo. 5,698,219; U.S. Patent No. 5,521,222; U.S. Patent No. 5,403,841; U.S. Patent No. 5,077,033; U.S. Patent No. 4,882,150; and U.S. Patent No. 4,738,851.

[0210] For prolonged delivery, the active componnd(s) or prodrug(s) can be formulated as a depot preparation for administration by implantation or intramuscular injection. The active ingredient may beformulated with suitable polymeric or hydrophobic materials (e.g., as an emulsion in an acceptable oil) or ion exchange resins, or as sparingly soluble derivatives, e.g., as a sparingly soluble salt. Alternatively, transdermal delivery systems manufactured as an adhesive disc or patch which slowly releases the active compound(s) for percutaneous absorption may be used. To this end, permeation enhancers may be used tofacilitate transdermal penetration of the active compound(s). Suitable transdermal patches are described in for example, U.S. Patent No. 5,407,713; U.S. PatentNo. 5,352,456; U.S. Patent No. 5,332,213; U.S. Patent No. 5,336,168; U.S. Patent No. 5,290,561; U.S. Patent No. 5,254,346; U.S. Patent No. 5,164,189; U.S. Patent No. 5,163,899; U.S. Patent No. 5,088,977; U.S. Patent No. 5,087,240; U.S. Patent No. 5,008,110; and U.S. Patent No. 4,921,475.

[0211] Alternatively, other pharmaceutical delivery systems may be employed. Liposomes and emulsions are well-known examples of delivery vehicles that may be used to deliver active compound(s) or prodrug(s). Certain organic solvents such as dimethylsulfoxide (DMSO) may also be employed, although usually at the cost of greater toxicity.

[0212] The pharmaceutical compositions may, if desired, be presented in a pack or dispenser device which may contain one or more unit dosage forms containing the active compound(s). The pack may, for examples, comprise metal or plastic foil, such as a blister pack. The pack or dispenser device may be accompanied by instructions for administration.

6.6 Effective Dosages [0213] The active compound(s) or prodrug(s) or compositions thereof, will generally be used in an amount effective to achieve the intended result, for example in an amount effective to treat or prevent the particular disease being treated. The compound(s) may be administered therapeutically to achieve therapeutic benefit or prophylactically to achieve prophylactic benefit. By therapeutic benefit is meant eradication or amelioration of the underlying disorder being treated and/or eradication or amelioration of one or more of the symptoms associated with the underlying disorder such that the patient reports an improvement in feeling or condition, notwithstanding that the patient may still be afflicted with the underlying disorder. For example, administration of a compound to a patient suffering from an allergy provides therapeutic benefit not only when the underlying allergic response is eradicated or ameliorated, but also when the patient reports a decrease in the severity or duration of the symptoms associated with the allergy following exposure to the allergen. As another example, therapeutic benefit in the context of asthma includes an improvement in respiration following the onset of an asthmatic attack, or a reduction in the frequency or severity of asthmatic episodes. Therapeutic benefit also includes halting or slowing the progression of the disease, regardless of whether improvement is realized.

[0214] For prophylactic administration, the compound may be administered to a patient at risk of developing one of the previously described diseases. For example, if it is unknown whether a patient is allergic to a particular drug, the compound may be administered prior to administration of the drug to avoid or ameliorate an allergic response to the drug. Alternatively, prophylactic administration may be applied to avoid the onset of symptoms in a patient diagnosed with the underlying disorder. For example, a compound may be administered to an allergy sufferer prior to expected exposure to the allergen. Compounds may also be administered prophylactically to healthy individuals who are repeatedly exposed to agents known to one of the above-described maladies to prevent the onset of the disorder. For example, a compound may be administered to a healthy indivídual who is repeatedly exposed to an allergen known to induce allergies, such as latex, in an effort to prevent the individual from developing an allergy. Alternatively, a compound may be administered to a patient suffering from asthma prior to partaking in activities which trigger asthma attacks to lessen the severity of, or avoid altogether, an asthmatic episode.

[0215] The amount of compound administered will depend upon a variety of factors, including, for example, the particular indication being treated, the mode of administration, whether the desired benefit is prophylactic or therapeutic, the severity of the indication being treated and the age and weight of the patient, the bioavailability of the particular active compound, etc. Determination of an effective dosage is well within the capabilities of those skilled in the art.

[0216] Effective dosages may be estimated initially from in vitro assays. For example, an initial dosage for use in animaJs may be formulated to achieve a circulating blood or serum concentration of active compound that is at or above an IC₅₀ of the particular compound as measured in as in vitro assay, such as the in vitro CHMC or BMMC and other in vitro assays described in the Examples section. Calculating dosages to achieve such circulating blood or serum concentrations taking into account the bioavailability of the particular compound is well within the capabilities of skilled artisans. For guidance, the reader is referred to Fingl &amp; Woodbury, "General Principles," In: Goodman and Gilman’s The Pharmaceutical Basis of Therapeutics, Chapter 1, pp. 1-46, latest edition, Pagamonon Press, and the references cited therein.

[0217] Initial dosages can also be estimated from in vivo data, such as animal models. Animal models useful for testing the efficacy of compounds to treat or prevent the various diseases described above are well-known in the art. Suitable animal models of hypersensitivity or allergic reactions are described in Foster, 1995, Allergy 50(21 Suppl):6-9, discussion 34-38 and Tumas et al., 2001, J. Allergy Clin. Immunol. 107(6):1025-1033. Suitable animal models of allergic rhinitis are described in Szelenyi et al., 2000, Arzneimittelforschung 50(11): 1037-42; Kawaguchi et al., 1994, Clin. Exp. Allergy 24(3):238-244 and Sugimoto et al„ 2000, Immunopharmacology 48(1):1-7. Suitable animal models of allergic conjunctivitis are described in Carreras et al., 1993, Br. J. Ophthalmol. 77(8):509-514; Saiga et al., 1992, Ophthalmic Res. 24 (1):45-50; and Kunert et al., 2001, Invest. Ophthalmol. Vis. Sci. 42(11):2483-2489. Suitable animal models of systemic mastocytosis are described in O’Keefe et al., 1987, J. Vet. Intern. Med. 1(2):75-80 and Bean-Knudsen et al„ 1989, Vet. Pathol. 26(1):90-92. Suitable animal models of hyper IgE syndromeare described in Claman etal., 1990, Clin. Immunol. Immunopathol. 56(1):46-53. Suitable animal models of B-cell lymphoma aredescribed in Hough et al., 1998, Proc. Natl. Acad. Sci. USA 95:13853-13858 and Hakim et al., 1996, J. Immunol. 157(12):5503-5511. Suitable animal models of atopic disorders such as atopic dermatitis, atopic eczema and atopic asthma are described in Chan et al., 2001, J. Invest. Dermatol. 117(4):977-983 and Suto et al., 1999, Int. Arch. Allergy Immunol. 120(Suppl 1 ):70-75. Ordinarily skilled artisans can routinely adapt such information to determine dosages suitable for human administration. Additional suitable animal models are described in the Examples section.

[0218] Dosage amounts will typically be in the range of from about 0.0001 or 0.001 or 0.01 mg/kg/day to about 100 mg/kg/day, but may be higher or lower, depending upon, among other factors, the activity of the compound, its bioavail-ability, the mode of administration and various factors discussed above. Dosage amount and interval may be adjusted individually to provide plasma levels of the compound(s) which are sufficient to maintain therapeutic or prophylactic effect. For example, the compounds may be administered once per week, several times per week (e.g., every other day), once per day or multiple times per day, depending upon, among other things, the mode of administration, the specific indication being treated and thejudgmentofthe prescribing physician. In casesof local administration orselective uptake, such as local topical administration, the effective local conœntration of active compound(s) may not be related to plasma concentration. Skilled artisans will be able to optimize effective local dosages without undue experimentation. [0219] Preferably, the compound(s) will provide therapeutic or prophylactic benefit without causing substantial toxicity. Toxicity of the compound(s) may be determined using standard pharmaceutical procedures. The dose ratio between toxic and therapeutic (or prophylactic) effect is the therapeutic index. Compounds(s) that exhibit high therapeutic indices are preferred.

[0220] The invention having been described, thefollowing examples areoffered by way of illustration and not limitation.

7. EXAMPLES

7.1 Synthesis of Starting Materials and Intermediates Useful for Synthesizing The 2,4-Pyrimidinediamine Compounds According to Schemes (l)-(V) [0221] A variety of starting materials and N4-monosubstituted-2-pyrimidineamines and N2-monosubstituted-4-pyrimi-dinediamines [mono Substitution Nucleophilic Aromatic Reaction (SNAR) products] useful for synthesizing the 2,4-pyrimidinediamine compounds of The invention according to Schemes (l)-(V) were prepared as described below. Conditions suitable for synthesizing the mono SNAR products are exemplified with 2-chloro-N4-(3,4-ethylenedioxyphenyl)-5-fluoro-4-pyrimidineamine (R926087).

<img file="IS2923B_D0113.tif" />

<img file="IS2923B_D0114.tif" />

<img file="IS2923B_D0115.tif" />

<img file="IS2923B_D0116.tif" />

<img file="IS2923B_D0117.tif" />

<img file="IS2923B_D0118.tif" />

<img file="IS2923B_D0119.tif" />

<img file="IS2923B_D0120.tif" />

<img file="IS2923B_D0121.tif" />

<img file="IS2923B_D0122.tif" />

<img file="IS2923B_D0123.tif" />

<img file="IS2923B_D0124.tif" />

<img file="IS2923B_D0125.tif" />

<img file="IS2923B_D0126.tif" />

<img file="IS2923B_D0127.tif" />

<img file="IS2923B_D0128.tif" />

<img file="IS2923B_D0129.tif" />

<img file="IS2923B_D0130.tif" />

<img file="IS2923B_D0131.tif" />

<img file="IS2923B_D0132.tif" />

<img file="IS2923B_D0133.tif" />

<img file="IS2923B_D0134.tif" />

<img file="IS2923B_D0135.tif" />

<img file="IS2923B_D0136.tif" />

<img file="IS2923B_D0137.tif" />

<img file="IS2923B_D0138.tif" />

<img file="IS2923B_D0139.tif" />

<img file="IS2923B_D0140.tif" />

<img file="IS2923B_D0141.tif" />

<img file="IS2923B_D0142.tif" />

<img file="IS2923B_D0143.tif" />

<img file="IS2923B_D0144.tif" />

<img file="IS2923B_D0145.tif" />

<img file="IS2923B_D0146.tif" />

<img file="IS2923B_D0147.tif" />

<img file="IS2923B_D0148.tif" />

<img file="IS2923B_D0149.tif" />

<img file="IS2923B_D0150.tif" />

<img file="IS2923B_D0151.tif" />

<img file="IS2923B_D0152.tif" />

<img file="IS2923B_D0153.tif" />

<img file="IS2923B_D0154.tif" />

<img file="IS2923B_D0155.tif" />

<img file="IS2923B_D0156.tif" />

<img file="IS2923B_D0157.tif" />

<img file="IS2923B_D0158.tif" />

<img file="IS2923B_D0159.tif" />

<img file="IS2923B_D0160.tif" />

<img file="IS2923B_D0161.tif" />

<img file="IS2923B_D0162.tif" />

<img file="IS2923B_D0163.tif" />

<img file="IS2923B_D0164.tif" />

<img file="IS2923B_D0165.tif" />

<img file="IS2923B_D0166.tif" />

<img file="IS2923B_D0167.tif" />

<img file="IS2923B_D0168.tif" />

<img file="IS2923B_D0169.tif" />

<img file="IS2923B_D0170.tif" />

<img file="IS2923B_D0171.tif" />

<img file="IS2923B_D0172.tif" />

<img file="IS2923B_D0173.tif" />

<img file="IS2923B_D0174.tif" />

<img file="IS2923B_D0175.tif" />

<img file="IS2923B_D0176.tif" />

<img file="IS2923B_D0177.tif" />

<img file="IS2923B_D0178.tif" />

<img file="IS2923B_D0179.tif" />

<img file="IS2923B_D0180.tif" />

<img file="IS2923B_D0181.tif" />

<img file="IS2923B_D0182.tif" />

<img file="IS2923B_D0183.tif" />

<img file="IS2923B_D0184.tif" />

<img file="IS2923B_D0185.tif" />

<img file="IS2923B_D0186.tif" />

<img file="IS2923B_D0187.tif" />

<img file="IS2923B_D0188.tif" />

<img file="IS2923B_D0189.tif" />

<img file="IS2923B_D0190.tif" />

<img file="IS2923B_D0191.tif" />

<img file="IS2923B_D0192.tif" />

<img file="IS2923B_D0193.tif" />

<img file="IS2923B_D0194.tif" />

<img file="IS2923B_D0195.tif" />

<img file="IS2923B_D0196.tif" />

<img file="IS2923B_D0197.tif" />

<img file="IS2923B_D0198.tif" />

<img file="IS2923B_D0199.tif" />

<img file="IS2923B_D0200.tif" />

<img file="IS2923B_D0201.tif" />

<img file="IS2923B_D0202.tif" />

<img file="IS2923B_D0203.tif" />

<img file="IS2923B_D0204.tif" />

<img file="IS2923B_D0205.tif" />

<img file="IS2923B_D0206.tif" />

<img file="IS2923B_D0207.tif" />

<img file="IS2923B_D0208.tif" />

<img file="IS2923B_D0209.tif" />

<img file="IS2923B_D0210.tif" />

<img file="IS2923B_D0211.tif" />

<img file="IS2923B_D0212.tif" />

<img file="IS2923B_D0213.tif" />

<img file="IS2923B_D0214.tif" />

<img file="IS2923B_D0215.tif" />

<img file="IS2923B_D0216.tif" />

<img file="IS2923B_D0217.tif" />

<img file="IS2923B_D0218.tif" />

<img file="IS2923B_D0219.tif" />

<img file="IS2923B_D0220.tif" />

<img file="IS2923B_D0221.tif" />

<img file="IS2923B_D0222.tif" />

<img file="IS2923B_D0223.tif" />

<img file="IS2923B_D0224.tif" />

<img file="IS2923B_D0225.tif" />

<img file="IS2923B_D0226.tif" />

<img file="IS2923B_D0227.tif" />

<img file="IS2923B_D0228.tif" />

<img file="IS2923B_D0229.tif" />

<img file="IS2923B_D0230.tif" />

<img file="IS2923B_D0231.tif" />

<img file="IS2923B_D0232.tif" />

<img file="IS2923B_D0233.tif" />

<img file="IS2923B_D0234.tif" />

<img file="IS2923B_D0235.tif" />

<img file="IS2923B_D0236.tif" />

<img file="IS2923B_D0237.tif" />

<img file="IS2923B_D0238.tif" />

<img file="IS2923B_D0239.tif" />

<img file="IS2923B_D0240.tif" />

<img file="IS2923B_D0241.tif" />

<img file="IS2923B_D0242.tif" />

<img file="IS2923B_D0243.tif" />

<img file="IS2923B_D0244.tif" />

<img file="IS2923B_D0245.tif" />

<img file="IS2923B_D0246.tif" />

<img file="IS2923B_D0247.tif" />

<img file="IS2923B_D0248.tif" />

<img file="IS2923B_D0249.tif" />

<img file="IS2923B_D0250.tif" />

<img file="IS2923B_D0251.tif" />

<img file="IS2923B_D0252.tif" />

<img file="IS2923B_D0253.tif" />

<img file="IS2923B_D0254.tif" />

<img file="IS2923B_D0255.tif" />

<img file="IS2923B_D0256.tif" />

<img file="IS2923B_D0257.tif" />

<img file="IS2923B_D0258.tif" />

<img file="IS2923B_D0259.tif" />

<img file="IS2923B_D0260.tif" />

<img file="IS2923B_D0261.tif" />

<img file="IS2923B_D0262.tif" />

<img file="IS2923B_D0263.tif" />

<img file="IS2923B_D0264.tif" />

<img file="IS2923B_D0265.tif" />

<img file="IS2923B_D0266.tif" />

<img file="IS2923B_D0267.tif" />

<img file="IS2923B_D0268.tif" />

<img file="IS2923B_D0269.tif" />

<img file="IS2923B_D0270.tif" />

<img file="IS2923B_D0271.tif" />

<img file="IS2923B_D0272.tif" />

<img file="IS2923B_D0273.tif" />

<img file="IS2923B_D0274.tif" />

<img file="IS2923B_D0275.tif" />

<img file="IS2923B_D0276.tif" />

<img file="IS2923B_D0277.tif" />

<img file="IS2923B_D0278.tif" />

<img file="IS2923B_D0279.tif" />

<img file="IS2923B_D0280.tif" />

<img file="IS2923B_D0281.tif" />

<img file="IS2923B_D0282.tif" />

<img file="IS2923B_D0283.tif" />

<img file="IS2923B_D0284.tif" />

<img file="IS2923B_D0285.tif" />

<img file="IS2923B_D0286.tif" />

<img file="IS2923B_D0287.tif" />

<img file="IS2923B_D0288.tif" />

<img file="IS2923B_D0289.tif" />

<img file="IS2923B_D0290.tif" />

<img file="IS2923B_D0291.tif" />

<img file="IS2923B_D0292.tif" />

<img file="IS2923B_D0293.tif" />

<img file="IS2923B_D0294.tif" />

<img file="IS2923B_D0295.tif" />

<img file="IS2923B_D0296.tif" />

<img file="IS2923B_D0297.tif" />

<img file="IS2923B_D0298.tif" />

<img file="IS2923B_D0299.tif" />

<img file="IS2923B_D0300.tif" />

<img file="IS2923B_D0301.tif" />

<img file="IS2923B_D0302.tif" />

<img file="IS2923B_D0303.tif" />

<img file="IS2923B_D0304.tif" />

<img file="IS2923B_D0305.tif" />

<img file="IS2923B_D0306.tif" />

<img file="IS2923B_D0307.tif" />

<img file="IS2923B_D0308.tif" />

<img file="IS2923B_D0309.tif" />

<img file="IS2923B_D0310.tif" />

<img file="IS2923B_D0311.tif" />

<img file="IS2923B_D0312.tif" />

<img file="IS2923B_D0313.tif" />

<img file="IS2923B_D0314.tif" />

<img file="IS2923B_D0315.tif" />

<img file="IS2923B_D0316.tif" />

<img file="IS2923B_D0317.tif" />

<img file="IS2923B_D0318.tif" />

<img file="IS2923B_D0319.tif" />

<img file="IS2923B_D0320.tif" />

<img file="IS2923B_D0321.tif" />

<img file="IS2923B_D0322.tif" />

<img file="IS2923B_D0323.tif" />

<img file="IS2923B_D0324.tif" />

<img file="IS2923B_D0325.tif" />

<img file="IS2923B_D0326.tif" />

<img file="IS2923B_D0327.tif" />

<img file="IS2923B_D0328.tif" />

<img file="IS2923B_D0329.tif" />

<img file="IS2923B_D0330.tif" />

<img file="IS2923B_D0331.tif" />

<img file="IS2923B_D0332.tif" />

<img file="IS2923B_D0333.tif" />

<img file="IS2923B_D0334.tif" />

<img file="IS2923B_D0335.tif" />

<img file="IS2923B_D0336.tif" />

<img file="IS2923B_D0337.tif" />

<img file="IS2923B_D0338.tif" />

<img file="IS2923B_D0339.tif" />

<img file="IS2923B_D0340.tif" />

<img file="IS2923B_D0341.tif" />

<img file="IS2923B_D0342.tif" />

<img file="IS2923B_D0343.tif" />

<img file="IS2923B_D0344.tif" />

<img file="IS2923B_D0345.tif" />

<img file="IS2923B_D0346.tif" />

<img file="IS2923B_D0347.tif" />

<img file="IS2923B_D0348.tif" />

<img file="IS2923B_D0349.tif" />

<img file="IS2923B_D0350.tif" />

<img file="IS2923B_D0351.tif" />

<img file="IS2923B_D0352.tif" />

<img file="IS2923B_D0353.tif" />

<img file="IS2923B_D0354.tif" />

<img file="IS2923B_D0355.tif" />

<img file="IS2923B_D0356.tif" />

<img file="IS2923B_D0357.tif" />

<img file="IS2923B_D0358.tif" />

<img file="IS2923B_D0359.tif" />

<img file="IS2923B_D0360.tif" />

<img file="IS2923B_D0361.tif" />

<img file="IS2923B_D0362.tif" />

<img file="IS2923B_D0363.tif" />

<img file="IS2923B_D0364.tif" />

<img file="IS2923B_D0365.tif" />

<img file="IS2923B_D0366.tif" />

<img file="IS2923B_D0367.tif" />

<img file="IS2923B_D0368.tif" />

<img file="IS2923B_D0369.tif" />

<img file="IS2923B_D0370.tif" />

<img file="IS2923B_D0371.tif" />

<img file="IS2923B_D0372.tif" />

<img file="IS2923B_D0373.tif" />

<img file="IS2923B_D0374.tif" />

<img file="IS2923B_D0375.tif" />

<img file="IS2923B_D0376.tif" />

<img file="IS2923B_D0377.tif" />

<img file="IS2923B_D0378.tif" />

<img file="IS2923B_D0379.tif" />

<img file="IS2923B_D0380.tif" />

<img file="IS2923B_D0381.tif" />

<img file="IS2923B_D0382.tif" />

<img file="IS2923B_D0383.tif" />

<img file="IS2923B_D0384.tif" />

<img file="IS2923B_D0385.tif" />

<img file="IS2923B_D0386.tif" />

<img file="IS2923B_D0387.tif" />

<img file="IS2923B_D0388.tif" />

<img file="IS2923B_D0389.tif" />

<img file="IS2923B_D0390.tif" />

<img file="IS2923B_D0391.tif" />

<img file="IS2923B_D0392.tif" />

<img file="IS2923B_D0393.tif" />

<img file="IS2923B_D0394.tif" />

<img file="IS2923B_D0395.tif" />

<img file="IS2923B_D0396.tif" />

<img file="IS2923B_D0397.tif" />

<img file="IS2923B_D0398.tif" />

<img file="IS2923B_D0399.tif" />

<img file="IS2923B_D0400.tif" />

<img file="IS2923B_D0401.tif" />

<img file="IS2923B_D0402.tif" />

<img file="IS2923B_D0403.tif" />

<img file="IS2923B_D0404.tif" />

<img file="IS2923B_D0405.tif" />

<img file="IS2923B_D0406.tif" />

<img file="IS2923B_D0407.tif" />

<img file="IS2923B_D0408.tif" />

<img file="IS2923B_D0409.tif" />

<img file="IS2923B_D0410.tif" />

<img file="IS2923B_D0411.tif" />

<img file="IS2923B_D0412.tif" />

<img file="IS2923B_D0413.tif" />

<img file="IS2923B_D0414.tif" />

<img file="IS2923B_D0415.tif" />

<img file="IS2923B_D0416.tif" />

<img file="IS2923B_D0417.tif" />

<img file="IS2923B_D0418.tif" />

<img file="IS2923B_D0419.tif" />

<img file="IS2923B_D0420.tif" />

<img file="IS2923B_D0421.tif" />

<img file="IS2923B_D0422.tif" />

<img file="IS2923B_D0423.tif" />

<img file="IS2923B_D0424.tif" />

<img file="IS2923B_D0425.tif" />

<img file="IS2923B_D0426.tif" />

<img file="IS2923B_D0427.tif" />

<img file="IS2923B_D0428.tif" />

<img file="IS2923B_D0429.tif" />

<img file="IS2923B_D0430.tif" />

<img file="IS2923B_D0431.tif" />

<img file="IS2923B_D0432.tif" />

<img file="IS2923B_D0433.tif" />

<img file="IS2923B_D0434.tif" />

<img file="IS2923B_D0435.tif" />

<img file="IS2923B_D0436.tif" />

<img file="IS2923B_D0437.tif" />

<img file="IS2923B_D0438.tif" />

<img file="IS2923B_D0439.tif" />

<img file="IS2923B_D0440.tif" />

<img file="IS2923B_D0441.tif" />

<img file="IS2923B_D0442.tif" />

<img file="IS2923B_D0443.tif" />

<img file="IS2923B_D0444.tif" />

<img file="IS2923B_D0445.tif" />

<img file="IS2923B_D0446.tif" />

<img file="IS2923B_D0447.tif" />

<img file="IS2923B_D0448.tif" />

<img file="IS2923B_D0449.tif" />

<img file="IS2923B_D0450.tif" />

<img file="IS2923B_D0451.tif" />

<img file="IS2923B_D0452.tif" />

<img file="IS2923B_D0453.tif" />

<img file="IS2923B_D0454.tif" />

<img file="IS2923B_D0455.tif" />

<img file="IS2923B_D0456.tif" />

<img file="IS2923B_D0457.tif" />

<img file="IS2923B_D0458.tif" />

<img file="IS2923B_D0459.tif" />

<img file="IS2923B_D0460.tif" />

<img file="IS2923B_D0461.tif" />

<img file="IS2923B_D0462.tif" />

<img file="IS2923B_D0463.tif" />

<img file="IS2923B_D0464.tif" />

<img file="IS2923B_D0465.tif" />

<img file="IS2923B_D0466.tif" />

<img file="IS2923B_D0467.tif" />

<img file="IS2923B_D0468.tif" />

<img file="IS2923B_D0469.tif" />

<img file="IS2923B_D0470.tif" />

<img file="IS2923B_D0471.tif" />

<img file="IS2923B_D0472.tif" />

<img file="IS2923B_D0473.tif" />

<img file="IS2923B_D0474.tif" />

<img file="IS2923B_D0475.tif" />

<img file="IS2923B_D0476.tif" />

<img file="IS2923B_D0477.tif" />

<img file="IS2923B_D0478.tif" />

<img file="IS2923B_D0479.tif" />

<img file="IS2923B_D0480.tif" />

<img file="IS2923B_D0481.tif" />

<img file="IS2923B_D0482.tif" />

<img file="IS2923B_D0483.tif" />

<img file="IS2923B_D0484.tif" />

<img file="IS2923B_D0485.tif" />

<img file="IS2923B_D0486.tif" />

<img file="IS2923B_D0487.tif" />

<img file="IS2923B_D0488.tif" />

<img file="IS2923B_D0489.tif" />

<img file="IS2923B_D0490.tif" />

<img file="IS2923B_D0491.tif" />

<img file="IS2923B_D0492.tif" />

<img file="IS2923B_D0493.tif" />

<img file="IS2923B_D0494.tif" />

<img file="IS2923B_D0495.tif" />

<img file="IS2923B_D0496.tif" />

<img file="IS2923B_D0497.tif" />

<img file="IS2923B_D0498.tif" />

<img file="IS2923B_D0499.tif" />

<img file="IS2923B_D0500.tif" />

<img file="IS2923B_D0501.tif" />

<img file="IS2923B_D0502.tif" />

<img file="IS2923B_D0503.tif" />

<img file="IS2923B_D0504.tif" />

<img file="IS2923B_D0505.tif" />

<img file="IS2923B_D0506.tif" />

<img file="IS2923B_D0507.tif" />

<img file="IS2923B_D0508.tif" />

<img file="IS2923B_D0509.tif" />

<img file="IS2923B_D0510.tif" />

<img file="IS2923B_D0511.tif" />

<img file="IS2923B_D0512.tif" />

<img file="IS2923B_D0513.tif" />

<img file="IS2923B_D0514.tif" />

<img file="IS2923B_D0515.tif" />

<img file="IS2923B_D0516.tif" />

<img file="IS2923B_D0517.tif" />

<img file="IS2923B_D0518.tif" />

<img file="IS2923B_D0519.tif" />

<img file="IS2923B_D0520.tif" />

<img file="IS2923B_D0521.tif" />

<img file="IS2923B_D0522.tif" />

<img file="IS2923B_D0523.tif" />

<img file="IS2923B_D0524.tif" />

<img file="IS2923B_D0525.tif" />

<img file="IS2923B_D0526.tif" />

<img file="IS2923B_D0527.tif" />

<img file="IS2923B_D0528.tif" />

<img file="IS2923B_D0529.tif" />

<img file="IS2923B_D0530.tif" />

<img file="IS2923B_D0531.tif" />

<img file="IS2923B_D0532.tif" />

<img file="IS2923B_D0533.tif" />

<img file="IS2923B_D0534.tif" />

<img file="IS2923B_D0535.tif" />

<img file="IS2923B_D0536.tif" />

<img file="IS2923B_D0537.tif" />

<img file="IS2923B_D0538.tif" />

<img file="IS2923B_D0539.tif" />

<img file="IS2923B_D0540.tif" />

<img file="IS2923B_D0541.tif" />

<img file="IS2923B_D0542.tif" />

<img file="IS2923B_D0543.tif" />

<img file="IS2923B_D0544.tif" />

<img file="IS2923B_D0545.tif" />

<img file="IS2923B_D0546.tif" />

<img file="IS2923B_D0547.tif" />

<img file="IS2923B_D0548.tif" />

<img file="IS2923B_D0549.tif" />

<img file="IS2923B_D0550.tif" />

<img file="IS2923B_D0551.tif" />

<img file="IS2923B_D0552.tif" />

<img file="IS2923B_D0553.tif" />

<img file="IS2923B_D0554.tif" />

<img file="IS2923B_D0555.tif" />

<img file="IS2923B_D0556.tif" />

<img file="IS2923B_D0557.tif" />

<img file="IS2923B_D0558.tif" />

<img file="IS2923B_D0559.tif" />

<img file="IS2923B_D0560.tif" />

<img file="IS2923B_D0561.tif" />

<img file="IS2923B_D0562.tif" />

<img file="IS2923B_D0563.tif" />

<img file="IS2923B_D0564.tif" />

<img file="IS2923B_D0565.tif" />

<img file="IS2923B_D0566.tif" />

<img file="IS2923B_D0567.tif" />

<img file="IS2923B_D0568.tif" />

<img file="IS2923B_D0569.tif" />

<img file="IS2923B_D0570.tif" />

<img file="IS2923B_D0571.tif" />

<img file="IS2923B_D0572.tif" />

<img file="IS2923B_D0573.tif" />

<img file="IS2923B_D0574.tif" />

<img file="IS2923B_D0575.tif" />

<img file="IS2923B_D0576.tif" />

<img file="IS2923B_D0577.tif" />

<img file="IS2923B_D0578.tif" />

<img file="IS2923B_D0579.tif" />

<img file="IS2923B_D0580.tif" />

<img file="IS2923B_D0581.tif" />

<img file="IS2923B_D0582.tif" />

<img file="IS2923B_D0583.tif" />

<img file="IS2923B_D0584.tif" />

<img file="IS2923B_D0585.tif" />

<img file="IS2923B_D0586.tif" />

7.5 The 2,4-Pyrimidinediamine Compounds of The invention Inhibit FceRI Receptor-Mediated Degranulation [0222] The ability of the 2,4-pyrimidinediamine compounds of The invention to inhibit IgE-induced degranulation was demonstrated in a variety of cellular assays with cultured human mast cells (CHMC) and/or mouse bone marrow derived cells (BMMC). Inhibition of degranulation was measured at both low and high cell density by quantifying the release of the granule specific factors tryptase, histamine and hexosaminidase. Inhrbition of release and/or synthesis of lipid mediators was assessed by measuring the release of leukotriene LTC4 and inhibition of release and/or synthesis of cytokines was monitored by quantifying TNF-α, IL-6 and IL-13. Tryptase and hexosaminidase were quantified using fluorogenic substrates as described in their respective examples. Histamine, TNFa, IL-6, IL-13 and LTC4 were quantified using the following commercial ELISA kits: histamine (Immunotech #2015, Beckman Coulter), TNFa (Biosource #KHC3011), IL-6 (Biosource #KMC0061), IL-13 (Biosource #KHC0132) and LTC4 (Cayman Chemical #520211). The protocols of the various assays are provided below.

7.5.1 Culturing of Human Mast and Basophil Cells [0223] Human mast and basophil cells were cultured from CD34-negative progenitor cells as described below (see also the methods described in copending U.S. application Serial No. 10/053,355, filed November8,2001, the disclosure of which is incorporated herein by reference).

7.5.1.1 Preparation of STEMPRO-34 Complete Medium [0224] To prepare STEMPRO-34 complete medium ("CM"), 250 mL STEMPRO-34™ serum free medium ("SFM"; GibcoBRL, Catalog No. 10640) was added to a filter flask. To this was added 13 mL STEMPRO-34 Nutrient Supplement ("NS"; GibcoBRL, Catalog No. 10641) (prepared as described in more detail, below). The NS container was rinsed with approximately 10 mL SFM and the rinse added to the filter flask. Following addition of 5 mL L-glutamine (200 mM; Mediatech, Catalog No. MT 25-005-CI and 5 mL 100X penicillin/streptomycin ("pen-strep"; HyClone, Catalog No: SV30010), the volume was brought to 500 mL with SFM and the solution was filtered.

[0225] The most variable aspect of preparing the CM is the method by which the NS is thawed and mixed prior to addition to the SFM. The NS should be thawed in a 37° C water bath and swirled, not vortexed or shaken, until it is completely in solution. While swirling, take note whether there are any lipids that are not yet in solution. If lipids are present and the NS is not uniform in appearance, return it to the water bath and repeat the swirling process until it is uniform in appearance. Sometimes this component goes into solution immediately, sometimes after a couple of swirling cycles, and sometimes not at all. If, after a couple of hours, the NS is still not in solution, discard it and thaw a fresh unit. NS that appears non-uniform after thaw should not be used.

7.5.1.2 Expansion of CD34+ Cells [0226] Astarting population of CD34-positive (CD34+) cellsof relatively small number (1-5 x 10⁶ cells) wasexpanded to a relatively large number of CD34-negative progenitor cells (about 2-4 x 10⁹ cells) using the culture media and methods described below. The CD34+ cells (from a single donor) were obtained from Allcells (Berkeley, CA). Because there is a degree of variation in the quality and number of CD34+ cells that Allcells typically provides, the newly delivered cells were transferred to a 15 mL conical tube and brought up to 10 mL in CM prior to use.

[0227] On day 0, a cell count was performed on the viable (phase-bright) cells and the cells were spun at 1200 rpm to pellet. The cells were resuspended to a density of 275,000 cells/mL with CM containing 200 ng/mL recombinant human Stem Cell Factor ("SCF"; Peprotech, Catalog No. 300-07) and 20 ng/mL human flt-3 ligand (Peprotech, Catalog No. 300-19) ("CM/SCF/flt-3 medium"). On about day 4 or 5, the density of the culture was checked by performing a cell count and the culture was diluted to a density of 275,000 cells/mL with fresh CM/SCF/flt-3 medium. On about day 7, the culture was transferred to a sterile tube and a cell count was performed. The cells were spun at 1200 rpm and resuspended to a density of 275,000 cells/mL with fresh CM/SCF/flt-3 medium.

[0228] This cycle was repeated, starting from day 0, a total of 3-5 times over the expansion period.

[0229] When the culture is large and being maintained in multiple flasks and is to be resuspended, the contents of all of the flasks are combined into a single container prior to performing a cell count. This ensures that an accurate cell count is achieved and provides for a degree of uniformity of treatment for the entire population. Each flask is checked separately for contamination under the microscope prior to combining to prevent contamination of the entire population. [0230] Between days 17-24, the culture can begin to go into decline (/.e., approximately 5-10% of the total number of cells die) and fail to expand as rapidly as before. The cells are then monitored on a daily basis during this time, as complete failure of the culture can take place in as little as 24 hours. Once the decline has begun, the cells are counted, spun down at 850 rpm for 15 minutes, and resuspended at a density of 350,000 cells/mL in CM/SCF/flt-3 medium to induce one or two more divisions out of the culture. The cells are monitored daily to avoid failure of the culture.

[0231] When greater than 15% cell death is evident in the progenitor cell culture and some debris is present in the culture, the CD34-negative progenitor cells are ready to be differentiated.

7.5.1.3 Differentiation of CD34-Negative Progenitor Cells into Mucosal Mast Cells [0232] A second phase is performed to convert the expanded CD34-negative progenitor cells into differentiated mucosal mast cells. These mucosal cultured human mast cells ("CHMC") are derived from CD34+ cells isolated from umbilical cord blood and treated to form a proliferated population of CD34-negative progenitor cells, as described above. To produce the CD43-negative progenitor cells, the resuspension cycle for the culture was the same as that described above, except that the culture was seeded at a density of 425,000 cells/mL and 15% additional media was added on about day four or five without performing a cell count. Also, the cytokine composition of the medium was modified such that it contained SCF (200 ng/mL) and recombinant human IL-6 (200 ng/mL; Peprotech, Catalog No. 200-06 reconstituted to 100 ug/mL in sterile 10 mM acetic acid) ("CM/SCF/IL-6 medium").

[0233] Phases I and II together span approximately 5 weeks. Some death and debris in the culture is evident during weeks 1 -3 and there is a period during weeks 2-5 during which a small percentage of the culture is no longer in suspension, but is instead attached to the surface of the culture vessel.

[0234] As during Phase I, when the culture is to be resuspended on day seven of each cycle, the contents of all flasks are combined into a single container prior to performing a cell count to ensure uniformity of the entire population. Each flask is checked separately for contamination under the microscope prior to combining to prevent contamination of the entire population.

[0235] When the flasks are combined, approximately 75% of the volume is transferred to the communal container, leaving behind about 10 mL or so in the flask. The flask containing the remaining volume was rapped sharply and laterally to dislodge the attached cells. The rapping was repeated at a right angle to the first rap to completely dislodge the cells. [0236] The flask was leaned at a 45 degree angle for a couple of minutes before the remaining volume was transferred to the counting vessel. The cells were spun at 950 rpm for 15 min priorto seeding at 35-50 mL perflask (at a density of 425,000 cells/mL).

7.5.1.4 Differentiation of CD34-Negative Progenitor Cells into Connective Tissue-Type Mast Cells [0237] A proliferated population of CD34-negative progenitor cells is prepared as above and treated to form a tryptase/ chymase positive (connective tissue) phenotype. The methods are performed as described above for mucosal mast cells, but with the substitution of IL-4 for IL-6 in the culture medium. The cells obtained are typical of connective tissue mast cells.

7.5.1.5 Differentiation of CD34-Negative Progenitor Cells into Basophil Cells [0238] A proliferated population of CD34-negative progenitor cells is prepared as described in Section 7.5.1.3, above, and used to form a proliferated population of basophil cells. The CD34-negative cells are treated as described for mucosal mast cells, but with the substitution of IL-3 (at 20-50 ng/mL) for IL-6 in the culture medium.

7.5.2 CHMC Low Cell Density IgE Activation: Tryptase and LTC4 Assays [0239] To duplicate 96-well U-bottom plates (Costar 3799) add 65 ul of compound dilutions or control samples that have been prepared in MT [137 mM NaCI, 2.7 mM KCI, 1.8 mM CaCI₂,1.0 mM MgCI₂, 5.6 mM Glucose, 20 mM Hepes (pH 7.4), 0.1% Bovine Serum Albumin, (Sigma A4503)] containing 2% MeOH and 1% DMSO. Pellet CHMC cells (980 rpm, 10 min) and resuspend in pre-warmed MT. Add 65 ul of cells to each 96-well plate. Depending on the degranulation activity for each particular CHMC donor, load 1000-1500 cells/well. Mix four times followed by a 1 hr incubation at 37°C. During the 1 hr incubation, prepare 6X anti-lgE solution [rabbit anti-human IgE (1 mg/ml, Bethyl Laboratories A80-109A) diluted 1:167 in MT buffer]. Stimulate cells by adding 25 ul of 6X anti-lgE solution to the appropriate plates. Add 25 ul MT to un-stimulated control wells. Mix twice following addition of the anti-lgE. Incubate at 37°C for 30 minutes. During the 30 minute incubation, dilute the 20 mM tryptase substrate stock solution [(Z-Ala-Lys-Arg-AMC2TFA; Enzyme Systems Products, #AMC-246)] 1:2000 in tryptase assay buffer [0.1 M Hepes (pH 7.5), 10 % w/v Glycerol, 10 uM Heparin (Sigma H-4898) 0.01 % NaN₃J. Spin plates at 1000 rpm for 10 min to pellet cells. Transfer 25 ul of supernatant to a 96-well black bottom plate and add 100 ul offreshly diluted tryptase substrate solution to each well. Incubate plates at room temperature for 30 min. Read the optical density of the plates at 355nm/460nm on a spectrophotometric plate reader.

[0240] Leukotriene C4 (LTC4) is also quantified using an ELISA kit on appropriately diluted supernatant samples (determined empirically for each donor cell population so that the sample measurement falls within the standard curve) following the supplier’s instructions.

7.5.3 CHMC High Cell Density IgE Activation: Degranulation (Tryptase, Histamine), Leukotriene (LTC4), and Cytokine (TNFalpha, IL-13) Assays [0241] Cultured human mast cells (CHMC) are sensitized for 5 days with IL-4 (20 ng/ml), SCF (200 ng/ml), IL-6 (200 ng/ml), and Human IgE (CP 1035Kfrom Cortx Biochem, 100-500ng/ml depending on generation) in CM medium. After sensitizing, cells are counted, pelleted (1000 rpm, 5-10 minutes), and resuspended at 1-2 x10⁶ cells/ml in MT buffer. Add 100 ul of cell suspension to each well and 100 ul of compound dilutions. The final vehicle concentration is 0.5% DMSO. Incubate at 37°C (5% CO₂) for 1 hour. After 1hour of compound treatment, stimulate cells with 6X anti-lgE. Mix wells with the cells and allow plates to incubate at 37°C (5% CO₂) for one hour. After 1 hour incubation, pellet cells (10 minutes, 1000 RPM) and collect 200 ul per well of the supernatant, being careful not to disturb pellet Place the supernatant plate on ice. During the 7-hour step (see next) perform tryptase assay on supernatant that had been diluted 1:500. Resuspend cell pellet in 240 ul of CM media containing 0.5% DMSO and corresponding concentration of compound. Incubate CHMC cells for 7 hours at 37°C (5% CO₂). After incubation, pellet cells (1000 RPM, 10 minutes) and collect 225 ul per well and place in -80°C until ready to perform ELISAS. ELISAS are performed on appropriately diluted samples (determined empirically for each donor cell population so that the sample measurement falls within the standard curve) following the supplier’s instructions.

7.5.4 BMMC High Cell Density IgE Activation: Degranulation (Hexosiminidase, Histamine), Leukotriene (LTC4), and Cytokine (TNFalpha, IL-6) Assays

7.5.4.1 Preparation of NMM-Conditioned Medium [0242] WEHI-conditioned medium was obtained by growing murine myelomonocytic WEHI-3B cells (American Type Culture Collection, Rockville, MD) in Iscove’s Modified Eagles Media (Mediatech, Hernandon, VA) supplemented with 10% heat-inactivated fetal bovine serum (FBS; JRH Biosciences, Kansas City, MO), 50 μΜ 2-mercaptoethanol (Sigma, St. Louis, MO) and 100 lU/mL penicillin-steptomycin (Mediatech) in a humidified 37°C, 5% CO₂/95% air incubator. An initial cell suspension was seeded at 200,000 cells/mL and then split 1:4 every 3-4 days over a period of two weeks. Cell-free supernatants were harvested, aliquoted and stored at -80°C until needed.

7.5.4.2 Preparation of BMMC Medium [0243] BMMC media consists of 20% WEHI-conditioned media, 10% heat-inactivated FBS (JHR Biosciences), 25 mM HEPES, pH7.4 (Sigma), 2mM L-glutamine (Mediatech), 0.1 mM non-essential amino acids (Mediatech), 1mM sodium pyruvate (Mediatech), 50 μΜ 2-mercaptoethanol (Sigma) and 100 lU/mL penicillin-streptomycin (Mediatech) in RPMI 1640 media (Mediatech). To prepare the BMMC Media, all components are added to a sterile IL filter unit and filtered through a 0.2 μηη filter prior to use.

7.5.43 Protocol [0244] Bone marrow derived mast cells (BMMC) are sensitized overnight with murine SCF (20 ng/ml) and monoclonal anti-DNP (10 ng/ml, Clone SPE-7, Sigma # D-8406) in BMMC media at a cell densityof 666x10³ cells/ml. Aftersensitizing, cells are counted, pelleted (1000 rpm, 5-10 minutes), and resuspended at 1-3 x10⁶ cells/ml in MT buffer. Add 100 ul of cell suspension to each well and 100 ul of compound dilutions. The final vehicle concentration is 0.5% DMSO. Incubate at 37°C (5% CO₂) for 1 hour. After 1 hour of compound treatment, stimulate cells with 6X stimulus (60 ng/ml DNP- BSA). Mix wells with the cells and allow plates to incubate at 37°C (5% CO₂) for one hour. After 1hour incubation, pellet cells (10 minutes, 1000 RPM) and collect 200 ul per well of the supernatant, being careful not to disturb pellet, and transfer to a clean tube or 96-well plate. Place the supematant plate on ice. During the 4-5 hour step (see next) perform the hexosiminidase assay. Resuspend cell pellet in 240 ul WEI-conditioned media containing 0.5% DMSO and corresponding concentration of compound. Incubate BMMC cells for 4-5 hours at 37°C (5% CO₂). After incubation, pellet cells (1000 RPM, 10 minutes) and collect 225 ul per well and place in -80°C until ready to perform ELISAS. ELISAS are performed on appropriately diluted samples (determined empirically for each donor cell population so that the sample measurement falls within the standard curve) following the supplier’s instructions.

[0245] Hexosaminidase assay: In a solid black 96-well assay plate, add 50 uL hexosaminidase substrate (4-methyl-umbelliferyl-N-acetyl-þ-D-glucosaminide; 2mM) to each well. Add 50 uL of BMMC cell supernatant (see above) to the hexoseaminidase substrates, place at 37°C for 30 minutes and read the plate at 5,10, 15, and 30 minutes on a spectrophotometer.

7.5.5 Basophil IgE or Dustmite Activation: Histamine Release Assay [0246] The basophil activation assay was carried out using whole human peripheral blood from donors allergic to dust mites with the majority of the red blood cells removed by dextran sedimentation. Human peripheral blood was mixed 1: 1 with 3% dextran T500 and RBCs were allowed to settle for 20-25min. The upper fraction was diluted with 3 volumes of D-PBS and cells were spun down for 10 min at 1500 rpm, RT. Supernatant was aspirated and cells were washed in an equal volume MT-buffer. Finally, cells were resuspended in MT-buffer containing 0.5% DMSO in the original blood volume. 80 uL cells were mixed with 20 uL compound in the presence of 0.5% DMSO, in triplicate, in a V-bottom 96-well tissue culture plate. A dose range of 8 compound concentrations was tested resulting in a 10-point dose response curve including maximum (stimulated) and minimum (unstimulated) response. Cells were incubated with compound for 1 hour at 37°C, 5% CO₂ after which 20 uL of 6x stimulus [1 ug/mL anti-lgE (Bethyl Laboratories) 667 au/mL house dustmite (Antigen Laboratories)] was added. The cells were stimulated for 30 minutes at 37°C, 5% CO₂. The plate was spun for 10 min at 1500 rpm at room temperature and 80 uL the supernatant was harvested for histamine content analysis using the histamine ELISA kit supplied by Immunotech. The ELISA was performed according to supplier’s instructions.

7.5.6 Results [0247] The results of low density CHMC assays (Section 7.5.2), the high density BMMC assays (Section 7.5.4) and the basophil assays (Section 7.5.5) are provided in TABLE 1. The results of the high density CHMC assays (Section 7.5.3) are provided in TABLE 2. In TABLES 1 and 2, all reported values are IC₅₀s (in μΜ). A value of "9999" indicates an IC₅₀&gt; 10μΜ, with no measurable activity at a 10μΜ concentration. Most compounds tested had IC₅₀s of less than 10μΜ, with many exhibiting IC₅₀s in the submicromolar range.

7.6 The 2,4-Pyrimidinediamine Compounds Inhibit FcyRI Receptor-Mediated Degranulation [0248] The ability of the 2,4-pyrimidinediamine compounds of The invention to inhibit FcyRI-mediated degranulation was demonstrated with Compounds R921218, R921302, R921303, R940347, R920410, R927050, R940350, R935372, R920323, R926971 and R940352 in assays similar to those described in Section 7.5, with the exception that the cells were not primed with IgE and were activated with rabbit anti-human IgG Fab fragment (Bethyl Laboratories, Catalog No. A80-105).

[0249] All of the compounds tested exhibited IC₅₀s in the sub micromolar range.

<img file="IS2923B_D0587.tif" />

<img file="IS2923B_D0588.tif" />

<img file="IS2923B_D0589.tif" />

<img file="IS2923B_D0590.tif" />

<img file="IS2923B_D0591.tif" />

<img file="IS2923B_D0592.tif" />

<img file="IS2923B_D0593.tif" />

<img file="IS2923B_D0594.tif" />

<img file="IS2923B_D0595.tif" />

<img file="IS2923B_D0596.tif" />

<img file="IS2923B_D0597.tif" />

<img file="IS2923B_D0598.tif" />

<img file="IS2923B_D0599.tif" />

<img file="IS2923B_D0600.tif" />

<img file="IS2923B_D0601.tif" />

<img file="IS2923B_D0602.tif" />

<img file="IS2923B_D0603.tif" />

<img file="IS2923B_D0604.tif" />

<img file="IS2923B_D0605.tif" />

<img file="IS2923B_D0606.tif" />

<img file="IS2923B_D0607.tif" />

<img file="IS2923B_D0608.tif" />

<img file="IS2923B_D0609.tif" />

<img file="IS2923B_D0610.tif" />

<img file="IS2923B_D0611.tif" />

<img file="IS2923B_D0612.tif" />

<img file="IS2923B_D0613.tif" />

<img file="IS2923B_D0614.tif" />

<img file="IS2923B_D0615.tif" />

<img file="IS2923B_D0616.tif" />

<img file="IS2923B_D0617.tif" />

<img file="IS2923B_D0618.tif" />

<img file="IS2923B_D0619.tif" />

<img file="IS2923B_D0620.tif" />

<img file="IS2923B_D0621.tif" />

<img file="IS2923B_D0622.tif" />

<img file="IS2923B_D0623.tif" />

<img file="IS2923B_D0624.tif" />

<img file="IS2923B_D0625.tif" />

<img file="IS2923B_D0626.tif" />

<img file="IS2923B_D0627.tif" />

<img file="IS2923B_D0628.tif" />

<img file="IS2923B_D0629.tif" />

<img file="IS2923B_D0630.tif" />

<img file="IS2923B_D0631.tif" />

<img file="IS2923B_D0632.tif" />

<img file="IS2923B_D0633.tif" />

<img file="IS2923B_D0634.tif" />

<img file="IS2923B_D0635.tif" />

<img file="IS2923B_D0636.tif" />

<img file="IS2923B_D0637.tif" />

<img file="IS2923B_D0638.tif" />

<img file="IS2923B_D0639.tif" />

<img file="IS2923B_D0640.tif" />

<img file="IS2923B_D0641.tif" />

<img file="IS2923B_D0642.tif" />

<img file="IS2923B_D0643.tif" />

<img file="IS2923B_D0644.tif" />

<img file="IS2923B_D0645.tif" />

<img file="IS2923B_D0646.tif" />

<img file="IS2923B_D0647.tif" />

<img file="IS2923B_D0648.tif" />

<img file="IS2923B_D0649.tif" />

7.7 The 2,4-Pyrimidinediamine Compounds of The invention Selectively Inhibit the Upstream IgE Receptor Cascade [0250] To confirm that many of the 2,4-pyrimidinediamine compounds of The invention exert their inhibitory activity by blocking or inhibiting the early IgE receptor signal transduction cascade, several of the compounds were tested in cellular assays for ionomycin-induced degranulation, as described below.

7.7.1 CHMC Low Cell Density lonomycin Activation: Tryptase Assay [0251] Assays for ionomycin-induced mast cell degranulation were carried out as described for the CHMC Low Density IgE Activation assays (Section 7.5.2, supra), with the exception that during the 1 hour incubation, 6X ionomycin solution [5mM ionomycin (Signma I-0634) in MeOH (stock) diluted 1:416.7 in MT buffer (2 μΜ final)] was prepared and cells were stimulated by adding 25 μΙ of the 6X ionomycin solution to the appropriate plates.

7.7.2 Basophil lonomycin Activation: Histamine Release Assay [0252] Assays for ionomycin-induced basophil cell degranulation were carried out as described for the Basophil IgE or Dustmite Activation Assay (Section 7.5.5, supra), with the exception that following incubation with compound, cells were stimulated with 20 μΙ of 2 μΜ ionomycin.

7.7.3 Results [0253] The results of the ionomycin-induced degranulation assays, reported as IC₅₀ values (in μΜ) are provided in TABLE 1, supra. Of the active compounds tested (i.e., those that inhibit IgE-induced degranulation), the vast majority do not inhibit ionomycin-induced degranulation, confirming that these active compounds selectively inhibit the early (or upstream) IgE receptor signal transduction cascade.

[0254] These results were confirmed for certain compounds by measuring anti-ígE-induced and ionomycin-induced calcium ion flux in CHMC cells. In these Ca²⁺ flux tests, 10 μΜ R921218 and 10 μΜ R902420 inhibited anti-lgE-induced Ca²⁺ flux, but had no effect on ionomycin-induced Ca²⁺ flux (See FIG. 4).

7.8 The Inhibitory Effect of the 2,4-Pyrimidinediamine Compounds of The invention is Immediate [0255] To test the immediacy of their inhibitory effect, certain 2,4-pyrimidinediamines of The invention were added simultaneously with anti-lgE antibody activator in the cellular assays described above. All compounds tested blocked IgE-induced degranulation of CHMC cells to the same extent as observed when the compounds were pre-incubated with CHMC cells for 10 or 30 min. prior to receptor cross-linking.

7.9 Kinetics of Pharmacological Activity In vitro [0256] Compounds R921218, R921302, R921219, R926240, R940277, R926742, R926495, R909243 and R926782 were tested in washout experiments. In the experiments, CHMC cells were either activated immediately with anti-lgE antibody in the presence of 1.25 μΜ compound (time zero), or the compound was washed out followed by activation with anti-lgE antibody at 30, 60 or 120 min. The inhibitory activity of these compounds was greatly diminished 30 min. after compound removal, indicating that constant exposure of mast cells to these compounds is required for maximal inhibition of degranulation The other compounds tested yielded similar results.

7.10 Toxicity: T- and B-Cells [0257] The ability of the compounds of The invention to exert their inhibitory activity without being toxic to cells of the immune system was demonstrated in cellular assays with B- and T-cells. The protocols for the assays are provided below.

7.10.1 Jurkat (T-Cell) Toxicity [0258] Dilute Jurkat cells to 2x10⁵ cells/ml in complete RPMI (10% heat-inactivated fetal bovine serum) media and incubate at 37°C, 5% CO2 for 18 hours. Add 65 ul cells at 7.7 x 10⁵ cells/ml to a 96-well V-bottom plate (TC-treated, Costar) containing 65 ul 2X compound (final vehicle concentration is 0.5% DMSO, 1.5% MeOH). Mix, incubate plates for 18-24 hr at 37°C, 5% CO2. Toxicity was assessed by flow cytometric analysis of cellular light scatter

7.10.2 BJAB (B-Cell) Toxicity [0259] The B-cell line BJAB was cultured in log phase in RPMI1640 + 10% heat-inactivated fetal bovine serum, 1x L-glutamine, 1x penicillin, 1x streptavidin and 1x betamercaptoethanol at 37°C, 5% CO2. First, BJABs were harvested, spun and resuspended in culture medium to a concentration of 7.7x10⁵ cells/mL. 65uL cells were mixed with 65 uL compound, in duplicate and in the presence of 0.1% DMSO in a V-bottomed 96-well tissue culture plate. Cells were incubated with compound at various dilutions at 37°C, 5% CO₂. Toxicity was assessed by flow cytometric analysis of cellular light scatter.

7.10.3 Toxicity: Cell Titer Glo Assay [0260] Seed 50 μΙ cells (1 x10⁶/ml) into each well containing 50 μΙ compound. The final vehicle concentration is 0.5% DMSO, 1.5% MeOH. Shake plates for 1 minute to mix cells and compound. Incubate plates at 37°C (5% CO₂) for 18 hours. Next day, harvest 50 μΙ cells from each well, add to 50 μΙ Cell Titer Glo reagent (Invitrogen). Shake plates for 1 minute. Read on luminometer.

7.10.4 Results [0261] The results of the T- and B-cell toxicity assays, reported as IC₅₀ values (in μΜ), are presented in TABLE 2, supra. With a few exceptions (see TABLE 1), all compounds tested were non-toxic to both B- and T-cells at effective inhibitory concentrations. Assays performed with primary B-cells yielded similar results.

7.11 The 2,4-Pyrimidine Compounds Are Tolerated In Animals [0262] The ability of the compounds of The invention to exert their inhibitory activity at doeses below those exhibiting toxicity in animals was demonstrated with compounds R921218, R921219 and R921302.

7.11.1 R921218 [0263] R921218 was studied in an extensive program of non-clinical safety studies that concluded this agent to be well tolerated in both rodents and non-rodents. To summarize the outcome of toxicology/non-clinical safety testing with R921218; this agent produced no dose limiting toxicity by the intranasal route of administration in non-rodents (rabbits and primates) or by the oral route of administration in rodents (mice and rats) during 14-day repeat-dose toxicity studies at doses many fold above the anticipated dose expected to produce efficacy in man. There were no adverse findings in a core safety pharmacology battery of cardiovascular, respiratory and/or central nervous system function. There was no evidence for mutagenic or clastogenic potential in genetic toxicology testing nor were there untoward effects after exposure to skin and eyes. A short discussion of key toxicology studies is provided.

[0264] A 14-day repeat-dose intranasal toxicity study in Cynomolgus monkeys was performed at doses of 2.1,4.5 or

6.3 mg/kg/day. In life parameters included: clinical observations, body weights, food consumption, ophthalmology, blood pressure, electrocardiography, hematology, clinical chemistry, urinalysis, immunotoxicological assessment, gross necropsy, organ weights, toxicokinetic assessments and histopathology (íncluding the nasal cavity). There were no adverse findings attributed to R921218 in any study parameter and the NOAEL (no observed adverse effect level) was considered 6.3 mg/kg/day.

[0265] A 14-day repeat-dose intranasal toxicity study in New Zealand White rabbits was performed at doses of 1.7,

3.4 or5.0 mg/kg/day. In life parameters included: clinical observations, body weights, food consumption, ophthalmology, hematology, clinical chemistry, gross necropsy, organ weights, toxicokinetic assessments and histopathology (including the nasal cavity). There were no adverse findings attributed to R921218 in any study parameter and the NOAEL (no observed adverse effect level) was considered 5.0 mg/kg/day.

7.11.2 R921219 [0266] In pilot dose finding studies a single dose oral dose of 600 mg/kg was considered a NOEL (no observed effect level) while multiple (7-day) doses of 200 mg/kg/day and above were not tolerated.

[0267] In the in vitro Salmonella Escherichia co//7Mammalian-Microsome Reverse Mutation Assay (Ames test), R921219 wasfound to test positive in testerstrain TA1537, with and without metabolic activation, confirming the results of an earlier study. R921219 was not found to adversely affect any of the other4 tester strains. R921219 was notfound to possess clastogenic potential when studied in an in vitro chromosomal aberration assay.

7.11.3 R921302 [0268] Several non-GLP pilot toxicity studies have been conducted in rodents. In the mousse an oral dose of 1000 mg/kg was tolerated for up to 7-days. In a 14-day oral toxicity study in the mouse was conducted with doses of 100, 300 and 1000 mg/kg. A dose of 1000 mg/kg was not tolerated, while a dose of 300 mg/kg promoted evidence for histopathological changes in the vulva. A dose of 100 mg/kg was considered the NOAEL (no observed adverse effect level) in the study. A 28-day oral toxicity study in the mouse was conducted at doses of 100 mg/kg q.d., 100 mg/kg b.i.d., 300 mg/kg q.d. and 300 mg/kg b.i.d. R921302 was not tolerated at 300 mg/kg q.d. or b.i.d. The lower doses (100 mg/kg q.d. or b.i.d.) appeared to be well tolerated (results of clinical and histopathology are not yet known). In the rat oral doses of 50, 150 and 300 mg/kg given for 32 days appeared to be well tolerated (results of clinical and histopathology are not yet known).

[0269] In the in vitro Salmonella-Escherichia co//7Mammalian-Microsome Reverse Mutation Assay (Ames test), R921302 was found to test positive in tester strain TA98 with S9 and TA1537, with and without metabolic activation. R921302 was not found to adversely affect any of the other 3 tester strains. R921302 was not clastogenic when assessed in an in vitro chromosomal aberration assay.

7.12 The 2,4-Pyrimidinediamine Compounds Are Orally Bioavailable [0270] Over 50 2,4-pyrimidinediamine compounds of The invention were tested for oral bioavailability. For the study, compounds were dissolved in various vehicles (e.g. PEG 400 solution and CMC suspension) for intravenous and oral dosing in the rats. Following administration of the drug, plasma samples were obtained and extracted. The plasma concentrations of the compounds were determined by high performance liquid chromatography/tandem mass spectrometry (LC/MS/MS) methods. Pharmacokinetic analyses were performed based on the plasma concentration data. The pharmacokinetic parameters of interest include Clearance (CL), Volume of distribution at steady-state (Vss), terminal half-life (t_1/2), and oral bioavailability (%F).

[0271 ] These pharmacokinetic studies indicate that many of the 2,4-pyrimidinediannine compounds are orally available, with %F up to approximately 50% (in the range of 0-50%). The half-lives ranged from 0.5 to 3 hr. In particular, Compounds R940350, R935372, R935193, R927050 and R935391 exhibited good oral bioavailabilities and half-lives in rats. Thus, these studies confirm that these 2,4-pyrimidinediamine compounds are suitable for oral administration.

7.13 The Compounds Are Effective for the Treatment of Allergies [0272] The /n vivo efficacy of compounds R926109, R921218, R921219, R921302, R926495, R926508, R926742, R926745 and R945150 towards allergies was evaluated in the mouse model of passive cutaneous anaphylaxis (PCA). This model provides a direct measure of IgE-induced degranulation of tissue mast cells. In this model, IgE primed animals are exposed to an allergen challenge, and the change in permeability of dermal vasculature that results from histamine release from mast cells is measured by change in the amount of dye leakage into surrounding tissue. Inhibition of mediator release by compounds that modulate mast cell degranulation is easily measured by extracting the dye from the tissue.

7.13.1 Study Protocol and Results [0273] In the PCA assay mice are passively sensitized by intradermal injection with anti-dinitrophenol (DNP) IgE antibodies (Day -1). At predetermined times animals are treated with the test agent (Day 0). The modulatory effect of the agent on cutaneous mast cell degranulation is measured following intravenous injection of DNP conjugated to human serum albumin (HSA-DNP), together with Evans blue dye. The resulting cross-linking of the IgE receptor and subsequent mast cell degranulation-induced increase in vascular permeability is determined by measuring the amount of dye extravasation into the tissue. Dye is extracted from the tissue by formamide, and the absorbance of this extract is read at 620 nm. The inhibitory effect of drug treatment is reported as the percent inhibition compared to vehicle treatment, that is, the percent reduction in Ag₂₀· [0274] Two compounds have been tested as positive controls: the histamine antagonist diphenhydramine and the serotonin antagonist cyproheptadine. Both mediators (histamine and serotonin) are released upon IgE-mediated degranulation from the mouse mast cell. Both reference compounds inhibit the PCA response; cyproheptadine was used routinely in subsequent experiements. Cyproheptadine reproducibly inhibited the PCA response by 61 % +/- 4% (8 mg/kg, i.p., 30 minutes pretreatment time, n=23 experiments).

7.13.1.1 Results [0275] A dose-dependent inhibition of the Fce R-mediated vascular leakage was observed with increasing doses of R921218, R926109, R921219 and RR921302. These compounds were administered either in a solution formulation (67%PEG/33% citrate buffer) or an aqueous suspension (1.5% Avicel). These results demonstrate the strong correlation between compound plasma levels, in vivo efficacy, and in vitro potency. The most potent compound, R921219, was active with circulating exposure levels of approximately 10 μg/ml (68% inhibition atadose level of 100 mg/kg) compared with R921302, a relatively less potent molecule, which reduced plasma extravasation by 42% at a dose level of 100 mg/kg. Further, the length of exposure to circulating compound was reflected in the duration of inhibitory activity. R921302, determined to be the most metabolically stable compound in pharmacokinetics studie, inhibited the vascular permeability for 1-2 hours prior to antigen-induced receptor signaling, where after the efficacy began to decrease. These data are summarized in TABLE 3 and TABLE 4.

<img file="IS2923B_D0650.tif" /> [0276] Similar in vivo activity was observed with compounds R926495, R926508, R926742, R926745 and R926150, which were able to inhibit the PCA response after administration by the oral route in a PEG-based formulation (data not shown).

7.14 The Compounds Are Effective in the Treatment of Asthma [0277] The efficacy of compounds R921218, R921302, R926495, R926508, R926742 and R921219 in the treatment

<img file="IS2923B_D0651.tif" />

of asthma was demonstrated in the sheep model of allergic asthma. Sheep develop bronchoconstriction within minutes of exposure to inhaled antigen (Ascaris suum), with maximal airflow obstruction during the early allergic response (EAR). Release of preformed mast cell mediators is likely responsible for this early phase of airflow obstruction. In addition to the EAR, the sheep model allows us to evaluate the effect of our compounds on the late asthmatic reaction (LAR) and non-specific airway hyperresponsiveness (AHR), which occur as a result of topical or local administration of allergen to the airway. In the sheep, AHR develops a few hours following antigen challenge, and can persist for up to 2 weeks. The results described below demonstrate the potential of the tested compounds to inhibit a cascade of events that may be a result of release of cytokines from the mast cell,

7.14.1 Study Protocol [0278] In the sheep model of allergic asthma, sheep are administered aerosols of test article via an endotracheal tube, followed by an aerosol challenge with antigen extracted from the roundworm, Ascaris suum, to which the sheep are naturally allergic. Allergen challenge leads to direct bronchoconstriction (both EAR and LAR) and a persistent nonspecific AHR. These three characteristics are similar to those seen in human allergic asthmatics. The activity of the test agent is determined by changes in the lung resistance (R_L), which is calculated from measurements of transpulmonary pressure, flow, and respiratory volume. The historical control data obtained from the same sheep following saline treatment compared with an allergen challenge show that a sharp increase of R_L occurs during the EAR and persists for approximately 2-3 hours following allergen challenge. The LAR is a less pronounced increase in R_L, which starts approximately 5-6 hours following allergen challenge and is resolved by 8 hours post-challenge. Twenty-four hours after the challenge, a dose response to carbachol is measured to determine the AHR, which is expressed as the dose of carbachol required to increase R_L by 400% over baseline. (This measurement is referred to as the provocative concentration of carbachol that elicits a 400% increase in RL over baseline (PC₄₀₀). The data are compared to historical control data for the same individual when administered a saline control aerosol and challenged with Ascaris suum.

7.14.2 Result [0279] All the compounds tested showed inhibitory effects in the LAR and the AHR, and several of these agents inhibited the EAR as well. The optimal response for each compound in a series of studies to evaluate activity at several pretreatment times and using several different solution and suspension formulations are shown in TABLE 5. The efficacy of R921218 on the EAR appeared to be dependent on the formulation, with the greatest effect seen at 30 mg/sheep administered as a solution aerosol in 10% ethanol. R926495, R926742, R926508 and R921219, administered in four different sheep at 45 mg/sheep in an aqueous suspension 60 minutes prior to allergen challenge, demonstrate that the LAR and AHR is blocked. In addition to these late parameters, the EAR was greatly reduced by treatment with R921219, R926508 or R926495. The efficacy of RR921302 was investigated using a 45%PEG400/55% citrate buffer vehicle. Under these conditions, R921302, administered at 30 mg/sheep 60 minutes prior to challenge, blocked the LAR and AHR, and EAR was unaffected.

[0280] These data clearly demonstrate that these compounds are able to block the asthmatic responses in allergic sheep. All compounds inhibited the AHR and LAR significantly when compared to the historical control. The EAR was significantly inhibited by R921219, R926508 and R926495 (54%,21% and 33% respectively). In contrast, R921218, R921302 and R926742 failed to inhibit the EAR when administered in an aqueous suspension.

TABLE 5 <img file="IS2923B_D0652.tif" />

<img file="IS2923B_D0653.tif" />

7.15 The Compounds Are Effective In The Treatment of Asthma [0281] The efficacy of compounds R921304 and R921219 in the treatment of asthma was also demonstrated in a mouse model of allergic asthma.

7.15.1 Study protocol [0282] Mice are sensitized to ovalbumin (chicken protein) in the presence of an adjuvant (Alum) by the intraperitoneal routeon day Oand day 7. One week later, mice are challenged intranasally with ovalbuminon Days 14,15and 16(more stringent model) or on Day 14 (less stringent model). This sensitization and challenge regimen leads to airway hyperresponsiveness and inflammation in the lungs, which are two dominant characteristics of human allergic asthma. In the mouse model, the in vivo airway responses are measured using a whole body plethysmograph which determines the PENH (enhanced Pause, Buxco Electronics). The PENH is a dimensionless value comprised of the peak inspiratory flow (PIF), peak expiratory flow (PEF), time of inspiration, time of expiration and relaxation time, and is considered a validated parameter of airway responsiveness. Responses to allergen challenge (OVA) are compared with animals challenged with saline only. Twenty-four hours after challenge, mice are exposed to increasing doses of methacholine (muscarinic receptor agonist) which results in smooth muscle contraction. The ovalbumin-challenged mice demonstrate a significant airway hyperresponsiveness to methacholine when compared to the saline challenged mice. In addition, a cellular infiltrate in the airway is observed in ovalbumin challenged mice when compared with the saline challenged mice. This cellular infiltrate is mainly characterized by eosinophils, but a smaller influx of neutrophils and mononuclear cells is also present.

[0283] The use of this model for the evaluation of small molecule inhibitors of mast cell degranulation has been validated is several ways. First, using mast cell deficient mice (W/W⁷) it has been shown that the ovalbumin-induced responses are dependent upon the presence of mast cells. In the mast cell deficient mice, ovalbumin sensitization and challenge did not result in airway hyperresponsiveness and eosinophil influx. Second, the mast cell stabilizer, Cromolyn, was able to block the ovalbumin-induced airway hyperresponsiveness and inflammation (data not shown). The use of this model to evaluate compounds for the treatment of asthmatic responses that may be mediated by mechanisms other than mast cell stablization, is further supported by the inhibitory effect of the steroids, dexamethasone and budesonide, on methacoline-induced bronchocontriction.

7.15.2 Results [0284] The efficacy of R921304 was evaluated by intranasal administration on 10 consecutive days, from Day 7 through Day 16, at a dose level of 20 mg/kg, with the last 3 doses administered 30 minutes prior to either saline or ovalbumin challenge. R921304 was able to inhibit the ovalbumin-induced airway hyperresponsiveness to methacholine when compared to the vehicle treated mice.

[0285] In a less stringent protocol, in which the mice were challenged with ovalbumin only once on Day 14, R921219 administered subcutaneously at 70 mg/kg in 67%PEG400/33% citrate buffer 30 minutes prior to saline or ovalbumin challenge, demonstrates that R921219 completely blocked the ovalbumin-induced airway hyperresponsiveness and cellular influx.

[0286] These results clearly demonstrate that R921219 and R921304 are efficacious in inh ibiting the airway responses in a mouse model of allergic asthma.

7.16 2,4-Pyrimidinediamine Compounds Inhibit Phosphorylation of Proteins Downstream of Syk kinase in Activated Mast Cells [0287] The inhibitory effect of the 2,4-pyrimidinediamine compounds on the phosphorylation of proteins downstream of Syk kinase was tested with compounds R921218, R218219 and R921304 in IgE receptor-activiated BMMC cells.

[0288] For the assay, BMMC cells were incubated in the presence of varying concentrations of test compound (0.08 μΜ, 0.4 μΜ, 2 μΜ and 10 μΜ) for 1 hr at 37°C. The cells were then stimulated with anti-lgE antibody as previously described. After 10 min, the cells were lysed and the cellular proteins separated by electrophoresis (SDS PAGE).

[0289] Following electrophoresis, the phosphorylation of the proteins indicated in FIGS. 7,10 and 11A-D were assessed by immunoblot. Antibodies were purchased from Cell Signaling Technology, Beverley, MA.

[0290] Referring to FIGS. 7, 10 and 11A-D, the indicated compounds tested inhibited phosphorylation of proteins downstream of Syk, but not upstream of Syk, in the IgE receptor signaling cascade, confirming both that the compounds inhibit upstream IgE induced degranulation, and that the compounds exert their inhibitory activity by inhibiting Syk kinase.

7.17 2,4-Pyrimidinediamine Compounds Inhibit Syk Kinase in Biochemical Assays [0291] Several 2,4-pyrimidinediamine compounds were tested for the ability to inhibit Syk kinase catalyzed phosphorylation of a peptide substrate in a biochemical fluorescenced polarization assay with isolated Syk kinase. In this exper-iment, Compounds were diluted to 1% DMSO in kinase buffer (20 mM HEPES, pH 7.4, 5 mM MgCI₂, 2 mM MnCI₂, 1 mM DTT, 0.1 mg/mL acetylated Bovine Gamma Globulin). Compound in 1% DMSO (0.2% DMSO final) was mixed with ATP/substrate solution at room temperature. Syk kinase (Upstate, Lake Placid NY) was added to a final reaction volume of 20 uL, and the reaction was incubated for 30 minutes at room temperature. Final enzyme reaction conditions were 20 mM HEPES, pH 7.4, 5 mM MgCI₂, 2 mM MnCI₂, 1 mM DTT, 0.1 mg/mL acetylated Bovine Gamma Globulin, 0.125 ng Syk, 4 uM ATP, 2.5 uM peptide substrate (biotin-EQEDEPEGDYEEVLE-CONH2, SynPep Corporation). EDTA (10 mM final)/anti-phosphotyrosine antibody (1X final)/fluorescent phosphopeptide tracer (0.5X final) was added in FP Dilution Bufferto stop the reaction for a total volume of 40 uL according to manufacturer’s instructions (PanVera Corporation) The plate was incubated for 30 minutes in the dark at room temperature. Plates were read on a Polarion fluorescence polarization plate reader (Tecan). Data were converted to amount of phosphopeptide present using a calibration curve generated by competition with the phosphopeptide competitor provided in the Tyrosine Kinase Assay Kit, Green (PanVera Corporation).

[0292] The results of the assay are shown in TABLE 6, below: <img file="IS2923B_D0654.tif" />

<img file="IS2923B_D0655.tif" />

<img file="IS2923B_D0656.tif" />

(continued) <img file="IS2923B_D0657.tif" /> [0293] Thesedata demonstrate that all of the compounds tested, exceptfor R945142 and R909236 inhibit Syk kinase phosphorylation with IC₅₀s in the submicromolar range. All compounds tested inhibit Syk kinase phosphorylation with IC₅₀s in the micromolar range.

7.18 The Compounds Are Effective for the Treatment of Autoimmunity [0294] The in vivo efficacy of certain 2,4-pyrimidinediamine compounds towards autoimmune diseases was evaluated in the reverse passive Arthus reaction, an acute model of antigen-antibody mediated tissue injury, and in several disease models of autoimmunity and inflammation. These models are similar in that antibody to a specific antigen mediates immune complex-triggered (IC-triggered) inflammatory disease and subsequent tissue destruction. IC deposition at specific anatomic sites (central nervous system (CNS) for experimental autoimmune encephalomyelitis (EAE) and synovium for collagen-induced arthritis (CIA)) leads to activation of cells expressing surface FcyR and FœR, notably mast cells, macrophages, and neutrophils, which results in cytokine release, and neutrophil chemotaxis. Activation of the inflammatory response is responsible for downstream effector responses, including edema, hemorrhage, neutrophil infiltration, and release of pro-inflammatory mediators. The consequences of these IC-triggered events are difficult to identify in autoimmune disorders; nonetheless, many investigators have demonstrated that inh ibition of the FcyR signali ng pathway in these animal models has resulted in a significant reduction in disease onset and severity.

7.18.1 The Compounds Are Effective In Mouse Arthus Reaction [0295] The in vivo efficacy of compounds R921302, R926891, R940323, R940347, and R921303 to inhibit the IC-triggered inflammatory cascade was demonstrated in a mouse model of Reverse Passive Arthus Reaction (RPA reaction).

7.18.1.1 Model [0296] ímmune complex (IC)-mediated acute inflammatory tissue injury is implicated in a variety of human autoimmune diseases, including vasculitis syndrome, sickserum syndrome, systemic lupus erythematosus (SLE), rheumatoid arthritis, Goodpasture’s syndrome, and glomerulonephritis. The classical experimental model for IC-mediated tissue injury is the reverse passive Arthus reaction. The RPA reaction model is a convenient in vivo method to study localized inflammation, induced by ICs, without systemic effects. Intradermal injection of antibodies (Abs) specific to chicken egg albumin (rabbit anti-OVA IgG), followed by intravenous (IV) injection of antigens (Ags), specifically chicken egg albumin (ovalbumin, OVA), causes perivascular deposition of ICs and a rapid inflammatory response characterized by edema, neutrophil infiltration and hemorrhage at the injection sites. Aspects of the mouse RPA reaction model resemble the inflammatory response of patients with rheumatoid arthritis, SLE and glomerulonephritis.

7.18.1.2 Study Protocol [0297] In this model system, test compounds are administered at several timepoints prior to administration of Abs and Ags. A solution of rabbit anti-OVA IgG (50μg in 25μΙ/ιτιοιΐ3β) is injected intradermally, and immediately following is an intravenous injection of chicken egg albumin (20 mg/kg of body weight) in a solution containing 1 % Evans blue dye. The degree of edema and hemorrhage is measured in the dorsal skin of C57BL/6 mice using the Evan’s Blue dye as an

<img file="IS2923B_D0658.tif" />

indicator of local tissue damage. Purified polyclonal rabbit IgG is used as a control.

[0298] Pretreatment time, in which the test compounds are administered prior to Ab/Ag challenge, depends on the pharmacokinetic (PK) properties of each individual compound. Four hours after induction of Arthus reaction, mice are euthanized, and tissues are harvested for assessment of edema. This model system allows us to rapidly screen the in vivo activity of many inhibitors.

7.18.1.3 Results [0299] All compounds tested were administered by the oral route.

[0300] R921302, when administered ata dose level of 50 mg/kg, 100 mg/kg, and200 mg/kg 60 minutes priorto Ab/Ag challenge in C57B16 mice, showed dose-dependent inhibition of edema formation (49.9 %, 93.2 %, and 99.1 %, respectively). Furthermore, R921302 showed not only a prophylactic inhibition of edema, but also therapeutic efficacy in which the edema was inhibited by 77.5% when the compound was administered 30 minutes post-challenge at a dose level of 100 mg/kg.

[0301] R940323 and R926891 showed the efficacy of edema inhibition by 32.4% and 54.9%, respectively, when administered at 200 mg/kg, 60 minutes prior to challenge. These compounds are much less bioavailable when administered orally, and systemic exposure levels were approximately 50-fold less that that seen with R921302 (data not shown). R940347 inhibited edema by 89% when administered at a dose level of 100 mg/kg, 2 hours priorto challenge. [0302] Compound R921303 showed 100%, 100%, and 93.6%, inhibition of edema formation when administered at a dose level of 200 mg/kg and a pretreatment time of 30, 60, and 120 minutes, respectively). The compound also demonstrated a dose-dependent inhibition of 65.4%, 81.2% and 100%, at doses of 50 mg/kg, 100 mg/kg and 200 mg/kg, respectively. Results for the compounds tested are summarized in Table 7. <img file="IS2923B_D0659.tif" />

<img file="IS2923B_D0660.tif" />

(continued) <img file="IS2923B_D0661.tif" />

<img file="IS2923B_D0662.tif" />

(continued) <img file="IS2923B_D0663.tif" />

7.18.2 The Compounds are effective in Mouse Collagen Antibody Induced Arthritis Model [0303] The in vivo efficacy of compound R921302 towards autoimmune diseases was demonstrated a mouse model of collagen antibody-induced arthritis (CAIA).

7.18.2.1 Model [0304] Collagen-induced arthritis (CIA) in rodents is frequently used as one of the experimental models for IC-mediated tissue injury. Administration of type II collagen into mice or rats results in an immune reaction that characteristically involves inflammatory destruction of cartilage and bone of the distal joints with concomitant swelling of surrounding tissues. CIA is commonly used to evaluate compounds that might be of potential use as drugs for treatment of rheumatoid arthritis and other chronic inflammatory conditions.

[0305] In recent years, a new technique emerged in CIA modeling, in which the anti-type II collagen antibodies are applied to induce an antibody-mediated CIA. The advantages of the method are: Short time for induction of disease (developing within 24-48 hrs after an intravenous (IV) injection of antibodies); arthritis is inducible in both CIA-susceptible and CIA-resistant mouse strains; and the procedure is ideal for rapid screening of antiinflammatory therapeutic agents. [0306] Arthrogen-CIA® Arthritis-inducing Monoclonal Antibody Cocktail (Chemicon International Inc.) is administered intravenously to Balb/c mice (2mg/mouse) on Day 0. Forty-eight hours later, 100 μΙ of LPS (25μg) is injected intraperitoneally. On Day 4, toes may appear swollen. By Day 5, one or two paws (particular the hind legs) begin to appear red and swollen. On Day 6, and thereafter, red and swollen paws will remain for at least 1-2 weeks. During the study, the clinical signs of inflammation are scored to evaluate the intensity of edema in the paws. The severity of arthritis is recorded as the sum score of both hind paws for each animal (possible maximum score of 8). The degree of inflammation with involved paws is evaluated by measurement of diameter of the paws. Body weight changes are monitored.

[0307] Animals are treated at the time of induction of arthritis, beginning on Day 0. Test compounds and control compounds are administered once a day (q.d.) or twice a day (b.i.d.), via per os (PO), depending on previously established PK profiles.

<img file="IS2923B_D0664.tif" />

[0308] At the end of the study (1-2 weeks after induction of arthritis), mice are euthanized and the paws are transected at the distal tibia using a guillotine and weighed. The mean ± standard error of the mean (SEM) for each group is determined each day from individual animal clinical scores, and hind paw weights for each experimental group are calculated and recorded at study termination. Histopathological evaluation of paws are obtained.

7.18.2.2 Results [0309] Administration of R921302 significantly suppressed the development of arthritis and the severity of the disease (p&lt;0.005), as shown by the changes in mean daily arthritis clinical scores (FIG. 12). The mean daily arthritic scores, from day 4 to 14, in treatment group were reduced between 71 to 92 % comparing to that of vehicle control group. The degreeof paw inflammation, by measurementofthe paw weight, was reduced in animalstreated with R921302 compared with the vehicle control group (FIG. 13). At the end of study, the degree of swelling was evaluated by measuring the weight of paws, which is indicated by a 99.9 % reduction in group treated with R921302 compared with mean paw weight of the vehicle control group (p&lt;0.002).

[0310] Histopathological evaluation of the resected paws revealed a marked synovitis consistent with CIA. Marked lesions were noted in animals treated with saline or vehicle; while lesions of lesser severity were found in R921302 treatment group. The joints were thickened with marked proliferation of the synovium. There is an increase in fibroblasts with a dense infiltration of neutrophils, lymphocytes, monocytes, macrophages and plasma cells. There is vascular proliferation with congestion, hemorrhage and edema. Pannus formation was present in the joint space and there was cartilage destruction. In drug treated group, the joints were close to normal or showed limited inflammation but without cartilage involvement.

Table 8. Group Average Histopathological Score (0-15)

Treatment Average total score ± SD

Saline control 9.8 ±2.1

Vehicle control 9.3 ±4.5

R921302 (100 mg/kg), twicedaily 5.1 ±1.9

Naive 0.0 ±0.0 [0311] Arthritic clinical scores and paw edema were reduced by an average of 20% in animals treated with R050 twice daily at a dose level of 100 mg/kg compared with untreated control (vehicle, p = 0.1). Paw edema was inhibited by approximately 26% compared with untreated control (vehicle), by measurement of hind paw thickness (p = 0.1). R050 did not exhibit arthritis at a dose level of 30 mg/kg.

[0312] R070, a saltform of R050, administered atdose levelsof 50 or 100 mg/kg twice daily inhibited clinical disease by an average of 39.75 % (p &lt; 0.0002) or 35.28% (p &lt; 0.0004) inhibition, respectively, compared with untreated control (vehicle). Paw thickness was reduced by approximately 50%.

[0313] R429, salt of R363, administered twice daily at 50 or 100 mg/kg showed an average of 23.81 % (p &lt; 0.05) or 20.82 % (p = 0.05) inhibition of arthritic clinical scores, respectively, compared with untreated control (vehicle). Likewise, paw thickness was reduced.

R.347 did not affect arthritic scores at the dose levels tested (30 and100 mg/kg twice daily).

7.18.3 The Compounds Are Effective In Rat Collagen-lnduced Arthritis [0314] The in vivo efficacy of compound R921302 towards autoimmune diseases was demonstrated in a rat model of collagen-induced arthritis (CIA).

7.18.3.1 Model Description [0315] Rheumatoid arthritis (RA) is characterized by chronicjoint inflammation eventually leading to irreversible cartilage destruction. IgG-containing IC are abundant in the synovial tissue of patients with RA. While it is still debated what role these complexes play in the etiology and pathology of the disease, IC communicate with the hematopoetic cells via the FcyR.

[0316] CIA is a widely accepted animal model of RA that results in chronic inflammatory synovitis characterized by pannus formation and joint degradation. In this model, intradermal immunization with native type II collagen, emulsified with incomplete Freund’s adjuvant, results in an inflammatory polyarthritis within 10 or 11 days and subsequent joint destruction in 3 to 4 weeks.

7.18.3.2 Study Protocol [0317] Syngeneic LOU rats were immunized with native type II collagen on Day 0, and efficacy of R921302 was evaluated in a prevention regimen and a treatment regimen. In the prevention protocol, either vehicle or various doses of R921302 were administered via oral gavage starting on day of immunization (Day 0). In the treatment protocol, after clinical signs of arthritis developed on Day 10, treatment with R921302 was initiated (300 mg/kg by oral gavage, qd) and continued until sacrifice on Day 28. In both protocols, clinical scores were obtained daily, and body weights are measured twice weekly. At Day 28, radiographic scores were obtained, and serum levels of collagen II antibody were measured by ELISA.

7.18.3.3 Results [0318] By 10 days after immunization, rats developed clinical CIA, asevidenced by an increase in theirarthritisscores (FIG. 14). The mean arthritic score gradually increased in the rats treated with vehicle alone after Day 10, and by Day 28 the mean clinical score reached 6.75 ± 0.57. Mean clinical scores in animals treated from the day of immunization (Day 0) with the high dose of R921302 (300 mg/kg/day) were significantly reduced (p&lt;0.01) on Days 10-28 compared with vehicle controls. In the rats treated with 300 mg/kg R921302 at disease onset, there was a significantly lower arthritis score beginning on Day 16, and this difference was observed until the end of the study on Day 28. Blinded radiographic scores (scale 0-6) obtained on Day 28 of CIA were 4.8 ± 0.056 in the vehicle group compared with 2.5 ± 0.0.16, 2.4 ± 0.006, and 0.13 ± 0.000001 in animals treated once daily with 75,150, and 300 mg/kg/day, respectively, in a prevention regimen, and 0.45 ± .031 in animals treated once daily with 300 mg/kg/day at onset of disease. R921302 treatment at 300 mg/kg/day, either prophylactically (at immunization) or after disease onset precluded the development of erosions and reduced soft tissue swelling. Similarly, R921302 treatment resulted in marked reduction of serum anti-collagen II antibody (data not shown).

7.18.4 The Compounds Are Effective In Mouse Experimental Autoimmune Encephalomyelitis [0319] The in vivo efficacy of compound R921302 towards autoimmune diseases was demonstrated in a mouse model of experimental autoimmune encephalomyelitis (EAE)

7.18.4.1 Model Description [0320] EAE is a useful model for multiple sclerosis (MS), an autoimmune disease of the CNS that is caused by immunecell infiltration of the CNS white matter. Inflammation and subsequent destruction of myelin cause progressive paralysis. Like the human disease, EAE is associated with peripheral activation of T cells autoreactive with myelin proteins, such as myelin basic protein (MBP), proteolipid protein (PLP), or myelin oligodendrocyte protein (MOG). Activated neuroantigen-specific T cells pass the blood-brain barrier, leading to focal mononuclear cell infiltration and demyelination. EAE can be induced in susceptible mouse strains by immunization with myelin-specific proteins in combination with adjuvant In the SJL mouse model used in these studies, hind limb and tail paralysis is apparent by Day 10 after immunization, the peak of disease severity is observed between Days 10 and 14, and a cycle of partial spontaneous remission followed by relapse can be observed up to Day 35. The results described below demonstrate the potential of the test agent (R921302) to suppress disease severity and prevent relapse of disease symptoms that may be the result of FcyR-mediated cytokine release from immune cells.

7.18.4.2 Study Protocol [0321] In the SJL murine model of EAE, each mouse is sensitized with PLP/CFA. (150 μg PLP139-151 with 200 μg CFA in 0.05 ml of homogenate on four sites of hind flank for a total of 0.2 ml emulsion is used to induce EAE). In a suppression protocol, either vehicle or various doses of R921302 are administered via oral gavage starting on the day of immunization (Day 0). In a treatment protocol, at onset of disease, animals are separated to achieve groups with a similar mean clinical score at onset and administered vehicle or various dose frequencies of test articles via oral gavage. In both protocols, clinical scores are monitored daily, and body weights are measured twice weekly.

7.18.43 Results [0322] By 10 days after PLP immunization, SJL mice developed clinical EAE, as evidenced by an increase in their mean clinical scores (FIG. 15). The paralytic score gradually increased in the animals treated with vehicle only from the day of immunization (Day 0), and by Day 14 the mean score reached a peak of 5.1 + 0.3. At disease peak (Day 14), the mean clinical score in animals treated with either 100 mg/kg daily or 100 mg/kg twice daily was significantly reduced (p &lt;0.05,4.3 + 1.3 and 4.3 + 1.4, respectively). By Day 16, all animals exhibited a partial remission of mean clinical severity, which is a characteristic of the SJL model. The markedly lower clinical scores in animals treated twice daily with 100 mg/kg R921302 remained significant (p &lt; 0.05) throughout the experiment until the animals were sacrificed on Day 30. These lower scores throughout the treatment period are reflected in the significantly lower cumulative disease index (CDI) and increase in cumulative weight index (CWI) as seen in Table 9. In the group treated with vehicle only, 2/5 of the mice relapsed. In the 100 mg/kg/day group, 3/8 of the mice relapsed. None of the mice in the 100 mg/kg twice daily group relapsed.

TABLE 9

SJL female mice treated with Rigel compound R921302 starting on day of immunization with 150 μg PLP 139-151/200 μg MTB (CFA)

Incidence Onset Peak Mortality CDI CWI

Placebo 10/10 11.8 ±0.5 5.1 ± 0.3 1/10® 53.2 ± 7.1 118.1 ±6.4

Control

100 10/10 12.3 ±0.7 4.3 ± 1.3 0/10 44.1 ± 14.5 124.4± 6.0 mg/kg

1x/day

100 10/10 13.0 ± 1.2^b 4.3 ±1.4 3/10® 33.7±11.4^b 133.5 ± 6.8^b mg/kg

2x/day

CDI = Cumulative Disease Index to day +26

CWI= Cumulative Weight Index to day +23 a= Mortality due to non-EAE, feeding related injuries or sacrificed hydrocephalic animals.

b= Significant difference between Control vs. Experimental groups (p &lt;0.05) determined via Students two-tailed t test.

[0323] SJL mice treated with R921302 at disease onset (Day 11) at a dose level of 200 mg/kg twice daily showed a significant decrease (p = 0.003) in CDI (53.5 ± 16.9 in animals treated with R921302 compared with 72.9 ± 8.9 in the animals treated with vehicle alone). Further, there was a dramatic decrease in the number of relapses in animals treated with R921302 (2/12) compared with the number of relapses in animals treated with vehicle (7/11). Results are summarized in Table 10 and FIG. 16.

TABLE 10

SJL female mice treated with Rigel compound R921302 starting on day of onset . Meanscoreat _ . . ... _. .

Incidence . . . Peak Mortahty Relapses CDI treatment

Control 11/11 3.9 ±1.6 5.0 ± 0.4 0/11 7/11 72.9 ± 8.9

200 mg/kg 2x/day 12/12 3.4 ± 1.6 4.3 ± 0.7 1/12 2/12 53.5±16.9

Pvalue 1.00 0.48 0.02 0.97 0.055 0.003

CDI = Cumulative Disease Index to day +27

7.18.5 The 2,4-Pyrimidinediamine Compounds of The invention Inhibit T-Cell Activation

7.18.5.1 Description [0324] The ability of the 2,4-pyrimidinediamine compounds of The invention to inhibit activation of T-Cells was shown using a variety of assays utilizing a Jurkat T-cell cell line and Primary T-cell cultures. Inhibition of activation of Jurkat T-cells in response to T-cell receptor (TCR) stimulation was measured by quantifying the upregulation of the cell surface marker CD69. Inhibition of primary T-cell activation was measured by quantifying the release of cytokines, including tumor necrosis factor alpha (TNF), interleukin 2 (IL-2), interleukin 4 (IL-4) interferon gamma (IFNg) and granulocyte macrophage colony stimulating factor (GMSCF), in response to TCR/CD28 co-stimulation.

7.18.5.2 Screening for Inhibition of Jurkat T-Cell Activation [0325] Human Jurkat T-cells (clone N) were routinely cultured in RPM11640 medium (Mediatech) supplemented with 10% fetal calf serum (FBS) (Hyclone), penicillin and streptamycin. The screening process took place overthree days.

[0326] On the first day of the screen, cultured cells were spun down on a centrifuge (1000 rpm, 5 minutes) and resuspended at 3.0 X 10⁵ cells/ml in RPMI + 5% FBS. On the second day of the screen, cells were spun down at 1000 rpm for 5 minutes and resuspended in RPMI + 5% FBS at 1.3 X 10⁵ cells/ml. 85 μΙ of this cell suspension were added to the wells of U-bottom 96 well plates (Coming). 85 μΙ of compound or diluted RPMI + 5% FBS (as a control) only was added to each well and incubated at 37° C for 1 hour. The cells were then stimulated with anti-TCR (C305) at: 500 ng/ml by adding a 8X solution in 25 μΙ to the plated cells. The cells were then incubated at 37°C for 20 hrs.

[0327] On the third day of the screen, the plates were spun at 2500 RPM for 1 minute on a Beckman GS-6R centrifuge, and the medium was then removed. 50 μΙ staining solution (1:100 dilution of anti-CD69-APC antibody (Becton Dickenson) in PBS + 2% FBS) was then added to each well, followed by incubation of the plates 4 degrees for 20 minutes in the dark 150 μΙ of wash buffer (PBS + 2% FBS) was then added to each well, and the plates were spun at 3000 RPM for 1 minute. The supernatant wase again removed, and the pellet was resuspended by vortexing gently. 75 μΙ of PBS + 2% FBS + Cytofix (1:4 dilution) was then added, the plates gently vortexed and wrap in aluminum foil. Cells from the plates were read using a flow cytometer coupled to an automated liquid handling system.

[0328] Varied concentrations of compound were compared to solvent only to determine the inhibition of T-cell activation IC₅₀of each compound. Representative IC₅₀sfor2,4-pyrimidinediamine compoundsofThe invention areshown in Table 11.

7.18.5.3 Isolation of Primary T-Cells [0329] 2E8-4E8 PBMC or proliferating T cells grown in rlL-2 from healthy human donors were suspended in PBS were spun down (1500 rpm, 8-10 minutes) and resuspended in 100 ml RPMI Complete media (1 % Pen-Strep, 1 % L-Glutamine, 10 mM HEPES). The cells were plated in T175 flasks (37°C, 5% CO₂) and monocytes were allowed to adhere for 2-3 hours. After monocyte attachment, non-adherent cells were harvested, counted by hemocytometer, washed several times with PBS then resuspended in Yssels Complete Media (Modified IMDM Media with 1% Human AB Serum, 1% Pen-Strep, 1% L-Glutamine, 10mM HEPES) at 1.54E6 cells/mL. 90 uLofthecelldilutionwerethenaddedtocompounds diluted to 2X in Yssel’s media and incubated for 30 minutes at 37°C (5% CO₂). After this preincubation step the compound/ cell mixture was transferred to stimulation plates, as described below.

7.18.5.4 Screening for Inhibition of Cytokine Production in Stimulated Primary T-Cell [0330] Stimulation plates were prepared by coating 96 well plates with 5 μο/ιτιΙ aCD3 (BD PharMingen, Catalog# 555336) + 10 μg/ml «CD28 (Beckman Coulter, Catalog# IM1376) in PBS (no Ca2⁺/Mg²⁺) at 37°C (5% CO₂) for at 3-5 hours. After incubation with the stimulation antibodies, the cocktail was removed and the plates washed 3 times with PBS priorto addition of the primary T cell/compound mixture.

[0331] The compound/cell mixture was transferred to the stimulation plates and incubatedfor 18 hrat 37°C (5% CO₂). After the cell stimulation, —150 μΙ supernatant were transferred from each well into 96-well filter plates (Corning PVDF Filter Plates) spun down (2000 rpm, 2-3 minutes) and either used immediately for ELISA or LUMINEX measurements or frozen down at -80°C for future use.

[0332] IL-2 ELISAs were perfomned using the Quantikine Human IL-2 ELISA kit (R&amp;D Systems, Catalog# D2050) as described by the manufacturer and absorption was measured on a spectrophotometer at 450 nm wavelength. Blank values were substracted and absorbances were converted to pg/mL based on the standard curve.

[0333] Luminex immunoassay multiplexing for TNF, IL-2, GMSCF, IL-4 and IFNg was performed essentially as described by the manufacturer (Upstate Biotechnology). Essentially 50 uL of sample was diluted into 50 uL assay diluent and 50 uL incubation buffer, then incubated with 100uL of the diluted detection antibody for 1 hr at RT in the dark. The filter plate was washed 2x in Wash Buffer, then incubated with 100 uL of the diluted secondary reagent (SAV-RPE) for 30 min at RT in the dark. Finally the plates were washed 3 times and bead identification and RPE fluorescent measured by the Luminex instrument.

[0334] Varied concentrations of compound were compared to solvent only to determine the inhibition of T-cell activation IC₅₀of each compound. Representative IC₅₀sfor2,4-pyrimidinediamine compoundsofThe invention areshown in Table 11.

7.18.6 The 2,4-Pyrimidinediamine Compounds of The invention. Inhibit B-Cell Activation

7.18.6.1 Description [0335] The ability of the 2,4-pyrimidinediamine compounds of The invention to inhibit activation of B-cells was shown using primary B-cells in a cell surface marker assay using a fluorescence activated cell sorter (FACS). Inhibition of activation of primary B-cells in response to B-cell receptor (BCR) stimulation was measured by quantifying the upregulation of the cell surface marker CD69.

7.18.6.2 Isolation of Primary B-Cells [0336] Primary human B-cells were isolated from buffy coat, the white cell layer that forms between the red cells and the platelets when anti-coagulated blood is centrifuged, or from fresh blood using CD19-Dynal® beads and a FACS. Buffy coat was obtained from the Stanford Medical School Blood Centre, prepared on the same day by the blood bank, stored and transported cold (with ice). The buffy coat (approx 35 mL) was placed in a 500 mL conical sterile centrifuge pot and cooled on ice, then diluted with cold PBS containing 0.2% BSA (Sigma: A7638) and sodium citrate (0.1 %, Sigma: S-5570) (P-B-C) to a total volume of200mL and mixed gently. Fresh blood was collected from donors in 10 mL vacutainers containing heparin (1 vacutainer collects approximately 8.5mL blood). The blood was cooled on ice, transferred into 50mL falcon tubes (20 mL/tube) or a 500 mL conical sterile centrifuge pot, and diluted with an equal volume P-B-C.

[0337] 25mL diluted blood or buffy coat was layered onto 15 mL cold ficoll and placed back on ice. The ficoll layered blood was centrifuged (Beckman GS-6R) for45 minutes at 2000 rpm, 4°C to separate the Peripheral Blood Mononuclear Cells (PBMC) from the Red Blood Cells (RBC) and granulocytes. The top aqueous layer was then aspirated until 1 inch above the PBMC layer. The PBMCs were transferred from every 2 ficoll tubes into one clean 50 mL falcon tube (=approx 10mL/tube). The transferred PBMCs were diluted 5x with icecold PBS with 0.2% BSA (P-B) and centrifuged for 20 min at 1400 rpm and 4°C. The supernatant (this may be cloudy) was then aspirated and the PBMCs resuspended into 25 mL P-B and the cells counted (using a 1:5 dilution) and kept on ice.

[0338] The cells were then positively selected using anti-CD19 antibody coupled to magnetic beads (Dynal®) as per manufacturer’s instructions. The approximate required amount of CD19-Dynal® beads (CD19-coated dyna beads M450 (pabB), Dynal®) was calculated by estimating the number of B-cells as 5% of PBMCs counted and adding approximately 10 beads per cell from the bead stock (4x10⁸ beads/mL). The CD19-Dynal® beads were washed 2x in P-B in a 5 mL tube using the Dynal® magnet, then added into the suspended PBMCs. This mixture was then passed through the Dynal® magnet and washed several times to separate the bead-bound cells.

7.18.6.3 Screening Compounds for Inhibition of B-cell Activation [0339] After separation, the beads and antibody were removed using Dynal® CD19-DETACHaBEAD® for 45 min at 30°C. Yield is typically 2X10⁷ B-cells per buffy coat. B-cells were washed and resuspended as 1E6 cells/mL in RPMI1640+10%FBS+ Penicillin/Streptavidin+ 1 ng/mL IFNa8. Cells were rested overnight at 37°C and 5% CO₂.

[0340] The following day, cells were washed and resuspended in RPMI+2.5% FBS to 1X10⁶cells/mL. Cells werethen aliquoted into a V-bottom 96-well plate (Coming) at 65 uL cells per well. By robot, 65uL of a 2x compound was added to the cells with final concentration of DMSO at 0.2%, and incubated for 1 hr at 37°C. Cells were then stimulated with 20 uL 7.5x a-lgM from Jackson laboratories (final 5 ug/mL) for 24 hrs. At day 3, the cells were spun down and stained for CD69 and analyzed by FACS gated on the live cells (by light scatter).

[0341 ] Varied concentrations of compound were compared to solvent only to determine the inhibition of B-cell activation IC₅₀ of each compound. Representative IC₅₀s for 2,4-pyrimidinediamine compounds of The invention are shown in Table 11.

7.18.7 The 2,4-Pyrimidinediamine Compounds of The invention Inhibit Macrophage Activation

7.18.7.1 Description [0342] The ability of the 2,4-pynmidinediamine compounds of The invention to inhibit activation of differentiated macrophages was shown by measuring the release of cytokines from stimulated macrophages. Release of tumor necrosis factor alpha (TNF) and interleukin 6 (IL-6) was quantified in response to IgG or LPS stimulation.

7.18.7.2 Purification and Culture of Human Macrophages [0343] CD14+ monocytes were purified from from PBMC (Allcells # PB002) using the Monocyte Isolation kit (Miltenyi biotec #130-045-501) as per the manufacturer’s instructions. Purity was assessed by measuring the percentage of CD14+ cells by flow cytometry. Typically &gt; 90% purity is achieved. The purified CD14+ cells are then plated out (6x10⁶.cells/150 cm TC dish in 15mls media) in Macrophage-SFM (Gibco #12065-074) with 100ng/ml of M-CSF (Pepro Tech #300-25) and allowed to differentiate for five days. At the end of that period, cell morphology and cell surface markers (CD14, HLA-DR, B7.1, B7.2, CD64, CD32, and CD16) reflected the presence of mature differentiated macrophage.

7.18.7.3 Stimulation with IgG [0344] Immulon 4HBX 96 well plates (VWR #62402-959) were coated with pooled human IgG (Jackson Immunoresearch lab#009-000-003) at 10ug/well overnight at 4°C or 1 hr at 37°C. A negative control consisting of the F(ab’)2 fragment was also coated to assess background stimulation. Unbound antibody was washed away 2X with 200ul PBS. 20ul of 5X compound was added to each well, followed by the addition 15k cells of differentiated macrophage in 80uL that had been scraped off of the plates. The cells were incubated for 16 hr in a 37°C incubator, and supernatants were collected for Luminex analysis for IL-6 and TNFa, essentially as described for the primary T-cells, above.

7.18.7.4 Stimulation with LPS [0345] Forstimulation with LPS, 10 uL of a 10X stock solution was added to the preincubated cell-compound mixture to a final concentration of 10 ng/mL. The cells were then incubated for 16hr at 37°C and supernatants were analyzed as described above.

[0346] Varied concentrations of compound were compared to solvent only to determine the IC₅₀ of each compound for each cytokine. Representative IC₅₀s for 2,4-pyrimidinediamine compounds of The invention are shown in Table 11. <img file="IS2923B_D0665.tif" />

<img file="IS2923B_D0666.tif" />

(continued) <img file="IS2923B_D0667.tif" />

<img file="IS2923B_D0668.tif" />

(continued) <img file="IS2923B_D0669.tif" />

<img file="IS2923B_D0670.tif" />

<img file="IS2923B_D0671.tif" />

<img file="IS2923B_D0672.tif" />

<img file="IS2923B_D0673.tif" />

<img file="IS2923B_D0674.tif" />

<img file="IS2923B_D0675.tif" />

<img file="IS2923B_D0676.tif" />

<img file="IS2923B_D0677.tif" />

<img file="IS2923B_D0678.tif" />

<img file="IS2923B_D0679.tif" />

<img file="IS2923B_D0680.tif" />

<img file="IS2923B_D0681.tif" />

<img file="IS2923B_D0682.tif" />

<img file="IS2923B_D0683.tif" />

<img file="IS2923B_D0684.tif" />

<img file="IS2923B_D0685.tif" />

<img file="IS2923B_D0686.tif" />

<img file="IS2923B_D0687.tif" />

<img file="IS2923B_D0688.tif" />

<img file="IS2923B_D0689.tif" />

<img file="IS2923B_D0690.tif" />

<img file="IS2923B_D0691.tif" />

<img file="IS2923B_D0692.tif" />

<img file="IS2923B_D0693.tif" />

<img file="IS2923B_D0694.tif" />

<img file="IS2923B_D0695.tif" />

<img file="IS2923B_D0696.tif" />

<img file="IS2923B_D0697.tif" />

<img file="IS2923B_D0698.tif" />

(continued) <img file="IS2923B_D0699.tif" /> [0347] Although the foregoing invention has been described in some detail to facilitate understanding, it will be apparent that certain changes and modifications may be practiced within the scope of the appended claims. Accordingly, the described embodiments are to be considered as illustrative and not restrictive, and The invention is not to be limited to the details given herein, but may be modified within the scope and equivalents of the appended claims.

[0348] All literature and patent references cited throughout the application are incorporated by reference into the application for all purposes.

<img file="IS2923B_D0700.tif" />