Efficacy and safety of venetoclax in combination therapy for relapsed acute myeloid leukemia after allogeneic hematopoietic stem cell transplantation

OBJECTIVE : To evaluate the efficacy of the B-cell lymphoma 2 (BCL2)-inhibitor venetoclax in combination therapy for relapsed acute myeloid leukemia (AML) patients after allogeneic hematopoietic stem cell transplantation (allo-HSCT). METHODS : We retrospectively analyzed 7 adults with relapsed AML who failed at least one prior therapy and were treated with venetoclax in combination with decitabine and/or low-dose cytarabine at the Beijing Boren hospital between March 2019 and March 2020. Four patients (57.1%) had adverse cytogenetic findings. Four patients (57.1%) had undergone a donor lymphocyte infusion (DLI) prior to venetoclax therapy, while four patients (57.1%) had leukemia and failed prior hypomethylating agent (HMA) therapy. RESULTS : The objective response rate (ORR) was 71.4% (5 patients achieved morphological complete remission with incomplete hematologic recovery, CRi). At the end of the follow-up period, 3/5 cases (60%) in the CRi group achieved minimal residual disease (MRD) negativity by flow cytometry. One patient (14.3%) successfully underwent allo-HSCT. The median follow-up time was 140 (120, 354) d. Among the seven patients, one died of relapse after remission, with an overall survival rate of 85.7% and a disease-free survival rate of 57.1% (4/7). Five of these patients (71.4%) had an identifiable infection, including septicemia (one patient), herpes zoster (two patients), and pneumonia (two patients). One patient had a tumor lysis syndrome. CONCLUSION : The venetoclax-based combinations demonstrated efficacy in treating adult patients with AML relapsing after allo-HSCT.