Impact of fitness categorization according to SIE/SIES/GITMO criteria in therapy-related and AML-MRC receiving CPX-351

CPX-351, a novel liposomal formulation of cytarabine and daunorubicin, represents the standard of care in fit patients with acute myeloid leukemia with myelodysplasia-related changes (AML-MRC) and therapy-related AML (t-AML). Considering its better safety profile than conventional intensive chemotherapy, we investigated its cost-to-benefit ratio, in terms of overall survival and of mortality, in a large multicentric series of AML-MRC and t-AML receiving CPX-351 outside clinical trials between 2019 and 2022. Patients were classified as fit or unfit for intensive chemotherapy through a comprehensive evaluation of age, comorbidities, and performance status by adopting Italian Society of Hematology/Italian Society of Experimental Hematology/Gruppo Italiano per il Trapianto di Midollo Osseo (SIE/SIES/GITMO) criteria. Disease risk was defined according to the European LeukemiaNet 2017 classification. Before treatment start, 328 of 403 (81.4%) patients were classified as fit and 75 of 403 (18.6%) as unfit. Three hundred and ninety-six had a full genetic/cytogenetic profile, with 17 (4%) being categorized as favorable risk, 162 (41%) intermediate risk, and 217 (55%) adverse risk according to European LeukemiaNet 2017. After induction, 230 of 403 (57.1%) patients achieved complete remission, with no differences between fit (57.3%) and unfit (56%) patients. However, the 2 groups significantly differed in terms of survival (median overall survival, 18 months vs 8 months for fit and unfit patients, respectively) and of 28- and 100-day mortality (4.6% vs 10.7% at 28 days and 14.3% vs 32% at 100 days for fit and unfit patients, respectively). In conclusion, the SIE/SIES/GITMO criteria distinguished patient subgroups with different short- and long-term outcomes after treatment with CPX-351. The update or design of dedicated fitness criteria could represent a future and valid strategy to optimize the use of this specific treatment.