Dr. Furman on FDA-Approved BTK Inhibitors in B-Cell Malignancies

Richard R. Furman, MD, a member of the Lymphoma/Myeloma Service in the Division of Hematology/Oncology and director of the CLL Research Center at Weill Cornell Medical College, discusses FDA-approved BTK inhibitors in B-cell malignancies.

Currently, 3 FDA-approved BTK inhibitorsare available for use in the United States, all of which work by covalently modifying the BTK enzyme, says Furman. Ibrutinib (Imbruvica), acalabrutinib (Calquence), and zanubrutinib (Brukinsa) covalently bind to the cysteine at the position 481 and block the BTK pocket, thus rendering the enzyme ineffective, explains Furman.

Currently, ibrutinib is approved for use in chronic lymphocytic leukemia (CLL), Waldenström macroglobulinemia, mantle cell lymphoma (MCL), and marginal zone lymphoma. Acalabrutinib received regulatory approval for use in CLL and MCL, and zanubrutinib is only approved for use in the MCL space.

All 3 drugs have similar benefits and investigators expect that their activity will be demonstrated or confirmed in the same histologies as ibrutinib has, concludes Furman.