Treatment-free remission (TFR) was maintained for at least 96 weeks among a subset of patients with chronic myeloid leukemia (CML) in chronic phase who had received frontline nilotinib, and was associated with molecular response (MR) during consolidation, according to an update of the ENESTfreedom study published in the Journal of Cancer Research and Clinical Oncology.1

The ongoing ENESTfreedom study is a single-arm phase 2 trial (ClinicalTrials.gov Identifier: NCT01784068) that enrolled 190 adults with Philadelphia chromosome–positive CML who received 2 or more years of frontline nilotinib and achieved MR4.5.

At the 96-week analysis, 48.9% (95% CI, 41.6-56.3%) of patients remained off-treatment and maintained major MR (MMR). Of those patients, nearly 95% were also in MR4.5. Patients who lost MMR restarted nilotinib, and, of those, 99% and 92% regained MMR and MR, respectively.

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Duration of TFR was associated with Sokal score; 61.3%, 50%, and 28.6% of patients with low, intermediate, and high Sokal scores, respectively, remained in TFR at 96 weeks.  TFR rates were also associated with MR. TFR duration was longest for patients who achieved MR4.5 during consolidation (82.6%), followed by patients who achieved MR4 but not MR4.5 (23.1%), and MMR but not MR4 at week 12 (0%).

The rate of adverse events decreased during the TFR phase. There were no CML-related deaths or CML progression during the study.

According to the authors, these results “demonstrate the durability of TFR following frontline nilotinib,” and support the use of nilotinib in the first-line among patients “for whom TFR might be a future treatment goal.”

Reference

Ross DM, Masszi T, Gomez Casares MT, et al. Durable treatment-free remission in patients with chronic myeloid leukemia in chronic phase following frontline nilotinib: 96-week update of the ENESTfreedom study [published online February 22, 2018]. J Cancer Res Clin Oncol. doi: 10.1007/s00432-018-2604-x

This article originally appeared on Cancer Therapy Advisor