[CAS NO. 330786-25-9]  PCI 29732

PCI-32765 blocks BCR signaling in human peripheral B cells at concentrations that does not affect T cell receptor signaling. In DOHH2 cells, PCI-32765 inhibits autophosphorylation of Btk (IC50, 11 nM), phosphorylation of Btk’s physiological substrate PLCγ(IC50, 29 nM), and phosphorylation of a further downstream kinase, ERK (IC50, 13 nM). PCI-32765 is more than 1,000-fold selective for inhibition of antigen receptor signaling in B cells over T cells, and that only B-cell inhibition is sustained following short duration treatment.