Real World Study on the Best CPX-351 Treatment Duration and Timing for Allogeneic Stem Cell Transplantation.

In the registration clinical trial 301 (NCT01696084), CPX-351 has shown to be superior to conventional 3 + 7 in secondary AML (s-AML). However, the optimal duration of treatment, the best timing for allogeneic stem cell transplantation (allo-HSCT), and the activity of CPX-351 in specific s-AML subgroups are unclear. To evaluate these aspects, a total of 513 s-AML patients (median age 65.6 years, 19-79) treated with CPX-351 were retrospectively analyzed. Complete remission (CR) rate after induction was 297/513 (58%), increasing to 340/513 (66%) after cycle 2. Among the 340 responding patients, 118 (34.7%), 137 (40.3%), and 85 (25%) received none, one, or two consolidation cycles of CPX-351, respectively. Overall, 230/513 patients (48.8%) received allo-HSCT. Median follow up was 23.66 months and median overall survival (OS) was 16.23 months. Patients with mutated NPM1 or with ELN 2017 favorable risk (p < 0.05) had a significantly longer OS (p < 0.05). In a landmark analysis, receiving allo-HSCT was associated with a longer survival (Median OS not reached vs. 16.3 months for patients receiving or not receiving allo-HSCT, p < 0.05). Completion of all allowed CPX-351 cycles was beneficial only in patients not proceeding to transplant (p < 0.05), whereas in transplanted patients additional CPX-351 cycles did not improve outcome. Our analysis suggests that also s-AML patients with NPM1 mutations and those belonging to the ELN 2017 favorable risk category benefit from CPX-351. In eligible patients, allo-HSCT should be performed as soon as a CR is achieved, whereas patients not undergoing transplant benefit from a complete CPX-351 schedule.