BMS-986142

BMS-986142 is a potent and highly selective reversible inhibitor of Bruton's tyrosine kinase (BTK) with an IC₅₀ of 0.5 nM. IC50 & Target: IC50: 0.5 nM (BTK), 10 nM (TEC), 15 nM (ITK), 23 nM (BLK), 28 nM (TXK), 32 nM (BMX), 71 nM (LCK), 1100 nM (SRC) ^[1]. In Vitro: BMS-986142 potently inhibits human recombinant BTK with an IC₅₀ of 0.5 nM in enzymatic assays. Against a panel of 384 kinases, BMS-986142 is highly selective, with only five other kinases (Tec, ITK, BLK, Txk, BMX) inhibited with <100-fold selectivity for BTK. Four of these kinases are Tec family kinases, of which BTK is a member, and only Tec (IC₅₀=10 nM) is inhibited with <30-fold selectivity compared with BTK. BMS-986142 does not inhibit CD40L-induced expression of CD86 or CD69 on peripheral blood B cells (IC₅₀>10,000 nM for both). When Ramos B cells are treated with anti-IgM to activate BCR, BMS-986142 inhibits BTK-dependent calcium flux with an IC₅₀ of 9 nM^[2]. In Vivo: BMS-986142 at 4, 10, and 30 mg/kg results in dose-dependent reductions of 26%, 43%, and 79% in clinically evident disease, respectively, at the end of the study. Interestingly, 4 mg/kg BMS-986142 provides an additive benefit in clinical scores (54% inhibition) when co-administered with MTX versus 19% inhibition with MTX alone. Co-administration of BMS-986142 at 4 mg/kg with MTX result in a 53% reduction in inflammation and bone resorption compared with 24% and 10%, respectively, with either drug alone. Furthermore, serum anti-collagen II IgG titers are significantly inhibited with 10 and 30 mg/kg BMS-986142. BMS-986142 also produces dose-dependent reductions in clinical scores when administration is delayed until the collagen booster on day 21. BMS-986142 doses of 2, 4, and 25 mg/kg in this therapeutic dosing regimen result in clinical score reductions of 17%, 37%, and 67%, respectively, at the end of the study^[2].