Nilotinib as frontline therapy for patients with newly diagnosed Ph+ chronic myeloid leukemia in chronic phase: results from the Japanese subgroup of ENESTnd.

Recent results from the phase 3 ENESTnd (Evaluating Nilotinib Efficacy and Safety in Clinical Trials-Newly Diagnosed Patients) study have demonstrated superiority of nilotinib over imatinib for the treatment of newly diagnosed Philadelphia chromosome-positive chronic myeloid leukemia in the chronic phase (CML-CP). Here, we report results from the Japanese subset of patients in ENESTnd, and assess whether results in this subpopulation are consistent with the overall study population. Seventy-nine Japanese patients with CML-CP were randomized to receive nilotinib 300 mg twice daily (BID) (n = 30), nilotinib 400 mg BID (n = 24) or imatinib 400 mg once daily (QD) (n = 25). Major molecular response rates at 12 months, the primary endpoint, were at least twice as high for nilotinib 300 mg BID (57%) and nilotinib 400 mg BID (50%) compared with imatinib 400 mg QD (24%). No patient on nilotinib progressed, while one patient progressed on imatinib. Both drugs were generally well tolerated and discontinuations due to adverse events were comparable among treatment arms. The results in the subpopulation of Japanese patients from ENESTnd closely mirror the results of the overall population, and support the use of nilotinib at 300 mg BID in Japanese patients with newly diagnosed CML-CP.