Treatment of therapy-related acute myeloid leukemia and acute myeloid leukemia with myelodysplasia-related changes: a comparative analysis of higher-dose intensive 7+3 induction chemotherapy versus liposomal cytarabine and daunorubicin.

Therapy-related acute myeloid leukemia (t-AML) and AML with myelodysplasia-related changes (AML-MRC) are associated with poor outcomes. The liposomal formulation of cytarabine and daunorubicin (CPX-351) improved complete remission (CR) and CR with incomplete hematologic recovery (CRi) rates and overall survival (OS) compared with 'standard' induction (7+3) chemotherapy in a phase-III trial for patients aged 60-75 years. However, 7+3 dosing varies among trials and in clinical practice and it remains unknown whether CPX-351 is superior to 7+3 double-induction regimens including intermediate-dose cytarabine, as the one employed in the HOVON-SAKK-Nordic clinical trials. To address this question, we conducted a post-hoc analysis on t-AML/AML-MRC patients aged ≥60 years enrolled in three HOVON-SAKK-Nordic trials and defined a subset of patients that met the eligibility criteria of the CPX-351 trial and compared their outcomes with those of the CPX-351 arm using reconstructed survival data. CR/CRi rates were higher in the higher-intensity 7+3 cohort (67.8%) compared with CPX-351 (47.7%) with similar median OS between the two cohorts (10.1 months versus 8.9 months respectively, HR = 0.99; 95% CI 0.78-1.26, p=0.95). Thirty-day mortality (4.4% for higher-intensity 7+3 versus 5.9% for CPX-351) and adverse events, including febrile neutropenia (61% for higher-intensity 7+3 versus 68% for CPX-351), were comparable. The data suggest that obligatory double-induction may achieve outcomes similar to CPX-351 in these patients and provide a strong rationale for ongoing clinical trials comparing these regimens.