Researchers conducted studies with PCI-32765 examining the downstream signaling events in the B-cell receptor (BCR) signal transduction pathways. In vitro drug treatment of B-cell lymphomas blocked BCR mediated signaling and in vivo drug treatment of lymphoma-bearing animal models resulted in inhibition of tumor growth.
Normal human B-cell activation was also inhibited by drug treatment in vitro. PCI-32765 also showed significant activity in animal models of arthritis.
Joseph Buggy, vice president of research at Pharmacyclics, said: “These studies highlight the importance of Btk in immune mediated diseases. Further, these data support our ongoing IND-enabling studies for PCI-32765, and our plans for an anticipated clinical trial later this year.”