Benefit of haploidentical hematopoietic stem cell transplantation for elderly patients with acute myeloid leukemia in first complete remission: A clinical observational study with in-depth time-dependent analysis

Abstract

The efficacy of haploidentical hematopoietic stem cell transplantation (haplo-HSCT) in elderly patients with acute myeloid leukemia (AML) remains poorly defined. This study aimed to assess the survival benefit of haplo-HSCT among elderly AML patients compared to chemotherapy. AML patients more than 60 years achieve first complete remission (CR1) following induction chemotherapy and eligible for haplo-HSCT between 2020 and 2023 were included in this retrospective study. A total of 110 AML patients were divided into two groups according to the treatments after CR1: haplo-HSCT ( n = 32) and no haplo-HSCT ( n = 78; receiving hypomethylating agents-based therapy or chemotherapy) groups. The impact of haplo-HSCT was evaluated using three statistical approaches: (1) a time-dependent Cox proportional hazards model, (2) a multistate model for dynamic prediction, and (3) a super landmark analysis. The median age of enrolled AML patients was 64 years (range, 60 – 71 years). Multivariate time-dependent analysis showed that haplo-HSCT significantly improved overall survival (OS; HR = 0.300, 95%CI 0.103 – 0.879; P = 0.028) and relapse-free survival (RFS; HR = 0.269, 95%CI 0.104 – 0.695; P = 0.007). According to the multistate model, patients who did not undergo haplo-HSCT had only a 7.1% probability of maintaining CR for four years after CR1, with a 57.7% probability of disease recurrence. Furthermore, the super-landmark analysis demonstrated that haplo-HSCT significantly improved both OS (HR = 0.249, 95%CI 0.072 – 0.867; P = 0.029) and RFS (HR = 0.258, 95%CI 0.077 – 0.861; P = 0.028). Haplo-HSCT significantly improves survival and reduces relapse in elderly AML patients who achieve CR1, establishing it as a viable and effective consolidative treatment strategy.