Second-line Nilotinib May Lead to Treatment-Free Remission in Chronic Phase CML

Long-term treatment-free remission (TFR) may be achievable among patients with chronic myeloid leukemia (CML) who had deep molecular response (DMR) after second-line nilotinib, according to a study published in the Annals of Internal Medicine.

BCR-ABL1 tyrosine kinase inhibitors (TKIs) have improved survival outcomes for CML dramatically, increasing the focus of TFR as a therapeutic outcome.

For the ENESTop phase 2 study, researchers enrolled 163 patients with CML who received TKI therapy for at least 3 years, and achieved DMR (MR^4.5) after switching to nilotinib for 2 years or longer after first-line imatinib; these patients underwent consolidation for 1 year on nilotinib.

Of the 163 patients, 77% (126) were eligible to discontinue nilotinib and enter the TFR phase. After 48 weeks, 58% (73) of patients remained in TFR and by week 96 53% (67) of patients remained in TFR.

Fifty-six patients were unable to maintain TFR and reinitiated nilotinib therapy, but 52 regained MR⁴ and MR^4.5 by the 96-week cutoff date; 50% of patients regained MR⁴ or MR^4.5 by week 12.0 and 13.1, respectively. 

No patients progressed to the accelerated or blast crisis phases of CML.

The most frequently reported adverse events (AE) during the consolidation phase included hypertension, pain in extremities, and nasopharyngitis. Among patients who entered TFR, 42% of patients experienced musculoskeletal pain in the first 48 weeks vs 14% of patients during consolidation.

The authors concluded that “TFR can be maintained for 48 weeks or longer in most patients who have achieved sustained DMR with second-line nilotinib. For those who do not achieve sustained DMR with imatinib, switching to nilotinib may enable more patients to become eligible for TFR.”

Reference

Mahon FX, Boquimpani C, Kim DW, et al. Treatment-free remission after second-line nilotinib treatment in patients with chronic myeloid leukemia in chronic phase [published online February 20, 2018]. Ann Intern Med. doi: 10.7326/M17-1094