Phase 3 study of nilotinib vs imatinib in Chinese patients with newly diagnosed chronic myeloid leukemia in chronic phase: ENESTchina

Abstract

Treatment with a tyrosine kinase inhibitor (TKI) targeting BCR-ABL1 is currently the standard of care for patients with chronic myeloid leukemia (CML) in chronic phase (CML-CP). In this study, we present results of the ENESTchina (Evaluating Nilotinib Efficacy and Safety in Clinical Trials-China) that was conducted to investigate nilotinib 300 mg twice daily vs imatinib 400 mg once daily in a Chinese population. ENESTchina met its primary end point with a statistically significant higher rate of major molecular response (MMR; BCR-ABL1 ≤0.1% on the International Scale) at 12 months in the nilotinib arm vs the imatinib arm (52.2% vs 27.8%; P < .0001), and MMR rates remained higher with nilotinib vs imatinib throughout the follow-up period. Rates of complete cytogenetic response (0% Philadelphia chromosome-positive [Ph+] metaphases by standard cytogenetics) were comparable and ≥80% by 24 months in both arms. The estimated rate of freedom from progression to accelerated phase/blast crisis at 24 months was 95.4% in each arm. The safety profiles of both drugs were similar to those from previous studies. In conclusion, rates of MMR at 12 months were superior with nilotinib vs imatinib in Chinese patients with newly diagnosed Ph+ CML-CP. This trial was registered at www.clinicaltrials.gov as #NCT01275196.

Figure 1

CONSORT diagram.

Figure 2

Cumulative incidence of MMR. * indicates patients with atypical transcripts at baseline or missing molecular assessments by the indicated time point were considered nonresponders. Absolute difference between rates of MMR in the nilotinib arm vs the imatinib arm: by 12 months, 25.1% (95% CI, 13.6%-36.6%); by 24 months, 15.3% (95% CI, 3.7%-26.9%). †, P value is nominal. ‡, Response rates consider each month to consist of one 28-day cycle.

Figure 3

Rates of CCyR. * indicates that patients with missing cytogenetic assessments by the indicated time point were considered nonresponders. †, Response rates consider each month to consist of one 28-day cycle. ‡, Percentages may not add up to 100 due to rounding. (A) Cumulative incidence of CCyR by 6, 12, and 24 months. (B) Cytogenetic responses at 6, 12, and 24 months.