Background:

A 419259 trihydrochloride is an orally available inhibitor of lck with IC50 value of 15 nM [1].

Lck is a src family tyrosine kinase. Inhibition of this enzyme results in a prevention of T-cell activation and provides an application for treating T-cell dependent processes such as autoimmune and inflammatory diseases. A 419259 trihydrochloride is screened out by its potent inhibitory activity against the recombinant lck (64–509) with IC50 value of 15nM. It is also a selective inhibitor. It shows inactive against a panel of other kinases including cMet, IGFR, PKC and PDGFR. Besides that, A 419259 trihydrochloride is found to inhibit the production of IL-2 with IC50 value of 25nM in Jurkat cells. Moreover, administration of A 419259 trihydrochloride reduces IL-2 production in mice with ED50 value of 2.5 mg/kg. A 419259 trihydrochloride also has efficacy of the antigen specific T-Cell immune response. Administration of this compound inhibits IFN-γ production during the in vivo priming phase [1].

Reference:
[1] Calderwood D J, Johnston D N, Munschauer R, et al.  Pyrrolo [2, 3-d] pyrimidines containing diverse N-7 substituents as potent inhibitors of Lck. Bioorganic & medicinal chemistry letters, 2002, 12(12): 1683-1686.