U.S. Food and Drug Administration Benefit-Risk Assessment of Nilotinib Treatment Discontinuation in Patients with Chronic Phase Chronic Myeloid Leukemia in a Sustained Molecular Remission

Abstract

On December 22, 2017, the U.S. Food and Drug Administration (FDA) updated the product label for nilotinib to include information for providers on how to discontinue this drug in certain patients. With the updated dosing recommendations, select patients with chronic phase myeloid leukemia (CML) taking nilotinib for 3 years or more and whose leukemia has responded with sustained molecular remission (MR4.5, BCR-ABL transcripts of ≤0.0032%) as determined by a FDA-approved test may be eligible to discontinue nilotinib. The updated dosing regimen was based on the efficacy results from two trials that measured how long patients could stop taking nilotinib without the leukemia returning (treatment-free remission). Trial results demonstrated that, among selected patients who received nilotinib as first-line therapy or after transition from imatinib, approximately 50% continued to be in remission at 96 weeks after stopping therapy. Relapses continued to occur throughout the study, indicating that long-term monitoring is needed for safety and disease monitoring. Discontinuation of treatment was associated with an increased risk of low grade musculoskeletal adverse events, some of which were prolonged. Overall, the results support the approval of updates to the dosing recommendations with regard to treatment discontinuation in selected patients who have received nilotinib for at least 3 years, are in a sustained molecular remission, and who can undergo appropriate monitoring. IMPLICATIONS FOR PRACTICE: The updated dosing information provides eligibility criteria for treatment discontinuation, strict monitoring criteria after nilotinib discontinuation, and guidance for treatment reinitiation in eligible patients with chronic phase myeloid leukemia. About half of appropriately selected patients remained in remission 96 weeks after treatment discontinuation. Patients may experience musculoskeletal pain on withdrawal of treatment, incidence of which appears to decrease over time; however, some patients may have long lasting events. The decision to withdraw or continue treatment with nilotinib should be based on clinical condition and patient preferences.

Keywords: BCR‐ABL; Chronic myeloid leukemia; Drug approvals; Treatment‐free remission; Tyrosine kinase inhibitors.