A new Bruton tyrosine kinase inhibitor has shown a high response rate and favorable safety profile in the treatment of patients with mantle cell lymphoma.
Researchers reported the results of an open-label, phase 2 study of oral acalabrutinib (100 mg, twice daily) in 124 patients with relapsed or refractory mantle cell lymphoma in The Lancet. Acalabrutinib (Calquence) received accelerated approval from the Food and Drug Administration in October 2017 for treatment of adults with mantle cell lymphoma who have received at least one prior therapy.
The Bruton tyrosine kinase (BTK) inhibitor ibrutinib (Imbruvica), which was approved in 2013 for the treatment of mantle cell lymphoma, has been associated with side effects including atrial fibrillation, infections and bleeding, likely due to its off-target activity against other kinases. But acalabrutinib (ACP-196) “is a highly selective, potent BTK inhibitor developed to minimise off-target activity,” wrote Michael Wang, MD, of the department of lymphoma and myeloma at the University of Texas MD Anderson Cancer Center, Houston, and his colleagues.
After a median follow-up of 15.2 months, 81% of patients in the study achieved an investigator-assessed overall response based on Lugano classification, with 40% achieving a complete response. The results were similar according to an independent review committee evaluation of responses based on CT and PET scans, bone-marrow biopsy specimens, endoscopy results, and clinical data.