Biological Activity
Ibrutinib (PCI-32765) is a selective, irreversible Btk inhibitor with an IC50 of 0.5 nM.
In Vitro
Ibrutinib (PCI-32765) selectively inhibits B-cell signaling and activation. It 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)[1]. Ibrutinib (PCI-32765) inhibits BCR-activated primary B cell proliferation (IC50=8 nM). Following FcγR stimulation, Ibrutinib (PCI-32765) inhibits TNFα, IL-1β and IL-6 production in primary monocytes (IC50=2.6, 0.5, 3.9 nM, respectively)[3].
In Vivo
Ibrutinib (PCI-32765) (3.125-50 mg/kg, p.o.) reduces the level of circulating autoantibodies and completely suppresses disease in mice with collagen-induced arthritis. Ibrutinib (PCI-32765) inhibits autoantibody production and the development of kidney disease in the MRL-Fas(lpr) lupus model. Ibrutinib (PCI-32765) (3.125-50 mg/kg, p.o.) reduces renal disease and autoantibody production in MRL-Fas(lpr) mice[1]. Ibrutinib (PCI-32765) (0.1 μM) inhibits activation-induced proliferation of CLL cells, induces selective cytotoxicity in B cells compared with T cells, but alters activation induced T-cell cytokine production[2]. Ibrutinib (PCI-32765) dose-dependently and potently reverses arthritic inflammation in a therapeutic CIA model with an ED50 of 2.6 mg/kg/day. Ibrutinib (PCI-32765) also prevents clinical arthritis in CAIA models[3].
References & source
Published experimental findings depend on the model and assay conditions. They do not guarantee equivalent performance in every application. For laboratory research use only.