Nilotinib combined with multiagent chemotherapy for newly diagnosed Philadelphia-positive acute lymphoblastic leukemia

Abstract

We investigated the effects of nilotinib plus multiagent chemotherapy, followed by consolidation/maintenance or allogeneic hematopoietic cell transplantation (allo-HCT) for adult patients with newly diagnosed Philadelphia-positive (Ph-pos) acute lymphoblastic leukemia (ALL). Study subjects received induction treatment that comprised concurrent vincristine, daunorubicin, prednisolone, and nilotinib. After achieving complete hematologic remission (HCR), subjects received either 5 courses of consolidation, followed by 2-year maintenance with nilotinib, or allo-HCT. Minimal residual disease (MRD) was assessed at HCR, and every 3 months thereafter. The molecular responses (MRs) were defined as MR3 for BCR-ABL1/G6PDH ratios ≤10(-3) and MR5 for ratios <10(-5). Ninety evaluable subjects, ages 17 to 71 years, were enrolled in 17 centers. The HCR rate was 91%; 57 subjects received allo-HCT. The cumulative MR5 rate was 94%; the 2-year hematologic relapse-free survival (HRFS) rate was 72% for 82 subjects that achieved HCR, and the 2-year overall survival rate was 72%. Subjects that failed to achieve MR3 or MR5 were 9.1 times (P = .004) or 6.3 times (P = .001) more prone to hematologic relapse, respectively, than those that achieved MR3 or MR5. MRD statuses just before allo-HCT and at 3 months after allo-HCT were predictive of 2-year HRFS. Adverse events occurred mainly during induction, and most were reversible with dose reduction or transient interruption of nilotinib. The combination of nilotinib with high-dose cytotoxic drugs was feasible, and it effectively achieved high cumulative complete molecular remission and HRFS rates. The MRD status at early postremission time was predictive of the HRFS. This trial was registered at www.clinicaltrials.gov as #NCT00844298.