Some info on BTK inhibitors...

Bruton's Tyrosine Kinase (BTK) Inhibitor Program

"BTK is an important cell signaling enzyme that is found in hematopoietic (blood) cells including B-cells. B-cell activation is driven by the B-cell receptor (BCR), and BTK is a crucial part of the BCR signaling pathway.

BCR signaling is thought to promote cell proliferation, adhesion, and survival in many types of B-cell malignancies (cancers). Inhibitors of BTK such as the Pharmacyclics compound, ibrutinib (PCI-32765), act downstream of the BCR and block BTK activity, and in preclinical models this resulted in an inhibition of proliferation, a disruption of tumor cell adhesion, and apoptosis (cell death) in malignant B-cells. Inhibition of BTK also blocked the recruitment and function of other immune cells including monocytes, macrophages, and mast cells. Studies in mice have shown that orally-dosed ibrutinib reduces the level of circulating autoantibodies and can reverse the course of arthritis. Ibrutinib also inhibited auto-antibody production and the development of kidney disease in a mouse model of systemic lupus erythematosus (SLE).

Therefore, targeted inhibition of BTK is a novel approach for treating many different human diseases associated with the inappropriate activation of B-cells, including B-cell malignancies, and potentially autoimmune and inflammatory disorders.

Pharmacyclics' BTK Inhibitor, ibrutinib, is an investigational, orally active, selective and irreversible small molecule that is in clinical development in a variety of B-cell malignancies (including chronic lymphocytic leukemia (CLL), small lymphocytic lymphoma (SLL), mantle cell lymphoma (MCL), and diffuse large B-cell lymphoma (DLBCL) and multiple myeloma (cancer of plasma cells, a type of white blood cell present in bone marrow).

To view an interview with Dr. Susan O’Brien on an update on kinase inhibitors, such as the BTK inhibitor, view the Patient Power interview with Dr. Susan O'Brien."

http://www.pharmacyclics.com/btk_inhibitors.html