Ibrutinib is a small molecule drug that inhibits B-cell proliferation and survival by irreversibly binding the protein Brutons tyrosine kinase (BTK). Blocking BTK inhibits the B-cell receptor pathway, which is often aberrantly active in B cell cancers.
It is indicated for the treatment of mantle cell lymphoma (MCL), chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL), Waldenstroems macroglobulinemia (WM), marginal zone lymphoma (MZL), and chronic graft versus host disease (cGVHD).