Ibrutinib

Ibrutinib, sold under the brand name Imbruvica among others, is a small molecule drug that inhibits B-cell proliferation and survival by irreversibly binding the protein Bruton's tyrosine kinase (BTK). Blocking BTK inhibits the B-cell receptor pathway, which is often aberrantly active in B cell cancers. Ibrutinib is therefore used to treat such cancers, including mantle cell lymphoma, chronic lymphocytic leukemia, and Waldenström's macroglobulinemia.^[1][2] See also Ibrutinib.

Tyrosine-protein kinase BTK with Ibrutinib (5p9j).

Ibrutinib binding site. Water molecules are shown as red spheres. brutinib is a potent, irreversible inhibitor of Bruton’s tyrosine kinase (BTK). The acrylamide group of ibrutinib forms a covalent bond with the cysteine residue C481 in the BTK active site, leading to sustained inhibition of BTK enzymatic activity. BTK is an important signalling molecule of the B-cell antigen receptor (BCR) pathway, which is plays a role in the pathogenesis of several B-cell malignancies including mantle cell lymphoma (MCL), diffuse large B-cell lymphoma (DLBCL), follicular lymphoma, and chronic lymphocytic leukemia (CLL). Preclinical studies have shown that ibrutinib effectively inhibits malignant B-cell proliferation and survival in vivo as well as cell migration and substrate adhesion in vitro.^[2]