BACKGROUND

Despite the poor prognosis for patients with relapsed/refractory (R/R) acute myeloid leukemia (AML), an optimal treatment strategy remains undefined. Mitoxantrone (MIT) is widely used to treat R/R AML.

METHODS

This prospective, single-center, open-label study assessed the efficacy and toxicity of mitoxantrone hydrochloride liposome (Lipo-MIT)-containing regimen therapy, intensified by adding cytarabine (Ara-C), cyclophosphamide (CTX) or other agents. The primary endpoint was composite complete remission (CRc), including complete remission (CR), complete remission with incomplete count recovery (CRi), and morphologic leukemia-free state (MLFS). The secondary endpoints included overall response rate (ORR), event-free survival (EFS), overall survival (OS), and safety.

RESULTS

We enrolled 20 patients (median, 38.50 years; range, 20.00-53.00 years) and treated them with a Lipo-MIT-containing regimen from April 29, 2022, to July 11, 2023. Twelve patients (60.00%) achieved CRc after one course of induction therapy, of which MAC (Lipo-MIT, Ara-C, CTX)-based regimen was the most commonly used (12/20, 60.00%) with a CRc rate of 66.67% (8/12). Additionally, 13 patients relapsed after allogeneic stem cell transplantation (allo-HSCT) with a CRc of 69.20% (9/13). The median follow-up time was 6.64 months, with a median OS of 9.99 months (range, 1.64-19.61; 95% confidence interval [CI], 2.05-17.92). Moreover, 95% patients experienced grade 3/4 hematologic treatment-related adverse events (TRAEs), including anemia (60.0%), thrombocytopenia (60.0%), leukopenia (65.0%), and neutropenia (55.0%). All patients experienced nonhematologic TRAEs, with 14 patients showing grade 3/4 toxicity.

CONCLUSION

The Lipo-MIT-based regimens demonstrate preliminary efficacy in R/R AML, particularly in those who relapsed after allo-HSCT, though hematologic toxicity warrants careful monitoring.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov Identifier: NCT04645199 in November 27, 2020.