Discontinuing treatment following 2-year consolidation therapy with nilotinib leads to durable treatment-free remission (TFR) among patients with chronic myeloid leukemia (CML) who achieved a deep molecular response (DMR), according to a study published in Haematologica.1
As treatment efficacy and outcomes improve among patients with CML, TFR is becoming the primary goal for therapy. Previous studies have shown that among patients who receive 1 year of consolidation therapy with the second-generation – tyrosine kinase inhibitor (2G-TKI) nilotinib and achieve DMR have comparable TFR rates as the rates associated with 2 years of therapy with imatinib, a first-generation TKI.
For the single-treatment STAT2 phase 2 study, researchers enrolled 96 Japanese patients with CML-chronic phase (CML-CP) who had achieved DMR — defined as BCR-ABL1IS ≤ 0.0032% or MR4.5—with imatinib or a 2G-TKI following imatinib. Patients received nilotinib 300 mg twice daily for 2 years during the consolidation phase; patients who maintained DMR during the consolidation phase progressed to the TFR phase and were able to stop nilotinib therapy.
Of the 96 patients, 78 maintained DMR and entered the TFR phase. Results showed that 53 patients (67.9%) did not experience molecular recurrence within the first 12 months, and the estimated 3-year treatment-free survival (TFS) was 62.8%.
Nilotinib was re-initiated among 29 patients who experienced disease recurrence and 25 of these participants (86.2%) regained DMR, with 50% of patients achieving DMR in 3.5 months.
Further analysis revealed that the TFS curve was significantly improved among patients with undetectable molecular residual disease with a 3-year TFS of 75.6% compared with 48.6% among patients with detectable levels (P = .0126). No significant differences in TFS were observed among patients regardless of treatment prior to nilotinib consolidation, among patients who had TKI-withdrawal syndrome (11 of 78 patients during early TFS phase), or in the absolute number of natural killer cells in patients across both cohorts.
The authors concluded that 2-year consolidation therapy with nilotinib “may be an effective strategy for achieving successful TFR in large numbers of CML patients.”
- Takahashi N, Nishiwaki K, Nakaseko C, et al. Treatment-free remission after two-year consolidation therapy with nilotinib in patients with chronic myeloid leukemia: STAT2 trial in Japan [published online July 5, 2018]. Haematologica. doi: 10.3324/haematol.2018.194894