Abstract
This study aimed to evaluate the efficacy and safety of programmed death receptor 1 (PD-1) antibody in patients with acute myeloid leukaemia (AML) or myelodysplastic syndrome (MDS) with minimal residual disease (MRD) after allogeneic haematopoietic stem cell transplantation (allo-HSCT). Six patients were retrospectively reviewed in this study, and all had failed prior treatment (donor lymphocyte infusion or interferon) before PD-1 antibody administration. Among these 6 patients, two received PD-1 alone while four received PD-1 plus azacitidine. The median treatment with the PD-1 antibody was four doses (range, 1-7 doses). Three patients developed > grade 3 toxicity, including 2 deaths. Among the five evaluable patients, four achieved negative MRD with a median time to response of 2 months (range: 1-3 months); and the median duration of response was 105 days (range: 26-211 days). The median survival time of the five patients was 320 days (range: 107-350 days). Our data suggest that anti-PD-1 antibody in AML/MDS patients with positive MRD following allo-HSCT may be a treatment option.