Treatment-free Remission Attempts Feasible in Patients Treated With Second-line Nilotinib for CML-CP

Treatment-free remission attempts in patients with chronic myeloid leukemia (CML), who have discontinued second-line nilotinib therapy after achieving a deep molecular response, are safe and likely to be achievable in the majority of patients in this setting, a study presented at the 2016 American Society of Clinical Oncology (ASCO) Annual Meeting has shown.¹

For this single-arm, phase 2 trial, researchers enrolled 163 patients with CML in chronic phase who were treated with a tyrosine kinase inhibitor for at least 3 years, including imatinib for more than 4 weeks followed by nilotinib for at least 2 years, and who had achieved a deep molecular response with niolotinib.

Patients continued nilotinib for 1 year, at which point patients without confirmed loss of deep molecular response were eligible to discontinue nilotinib. Upon confirmed loss of deep or major molecular response, nilotinib was reinitiated.

Results showed that 126 patients entered treatment-free remission after a median therapy duration  of 53 months. Of these patients, 57.9% (95% CI, 48.8-66.7) remained in treatment-free remission at 48 weeks.

Researchers found that during treatment-free remission, 18 patients had confirmed loss of deep molecular response, 34 lost major molecular response, and 1 patient came off the study due to atypical transcript. Of the 51 patients who reinitiated nilotinib, 98% re-achieved at least a major molecular response and most regained a deep molecule response.

No new safety signals were observed on nilotinib treatment. All grade musculoskeletal pain (42.1% versus 14.3%) and fluid retention (10.3% versus 1.6%) occurred more frequently in treatment-free remission group, in contrast with patients receiving nilotinib consolidation.
Cardiovascular events were more common in the nilotinib group (4.8% versus 0%).                                  

Reference

1. Hughes TP, Boquimpani C, Kim DW, Benyamini N, Clementino NC, Shuvaev V, et al. Treatment-free remission (TFR) in patients (pts) with chronic myeloid leukemia in chronic phase (CML-CP) treated with second-line nilotinib (NIL): First results from the ENESTop study. J Clin Oncol. 2016; 34 (suppl; abstr 7054).