Branebrutinib

Branebrutinib is a potent covalent, irreversible inhibitor of Bruton's tyrosine kinase (BTK). BTK is a non-receptor tyrosine kinase. It is a member of the Tec family of kinases and is essential for B cell receptor (BCR) mediated signaling. Branebrutinib inhibits BTK with IC₅₀ values of 0.1 nM, 0.9 nM, 1.5 nM and 5 nM for BTK, TEC, BMX and TXK respectively. It inactivates BTK in the human whole blood assay rapidly at a rate of 3.5 × 10−4 nM−1min-1. Branebrutinib inhibits signaling and functional end points, including calcium flux (IC₅₀ = 7 nM), production of cytokines, proliferation, and surface expression of the costimulatory molecule CD86 (IC₅₀ values < 1 nM) in B cells stimulated through the B cell receptor.