Fludarabine, cytarabine, and idarubicin with or without venetoclax in patients with relapsed/refractory acute myeloid leukemia

Treatment options for relapsed and refractory acute myeloid leukemia patients (R/R AML) are limited. This retrospective cohort study compares safety and efficacy of fludarabine, cytarabine, and idarubicin (FLA-IDA) with or without venetoclax in patients with R/R AML. Thirty-seven and 81 patients received one course FLA-IDA with or without a 7-day course of venetoclax, respectively. The overall response rate (ORR) was significantly higher in FLAVIDA compared to FLA-IDA treated patients (78% vs. 47%; P=0.001), while MRD was negative at a similar proportion in responding patients (50% vs. 57%), respectively. Eightyone percent and 79% of patients proceeded to allogeneic hematopoietic cell transplantation (alloHCT) or donor lymphocyte infusion (DLI) after FLAVIDA and FLA-IDA, respectively. Event-free and overall survival were similar in FLAVIDA and FLA-IDA treated patients. Refractory patients could be salvaged more successfully after FLA-IDA compared to FLAVIDA pretreatment. Neutrophil and platelet recovery times were similar in the venetoclax and the control group. In conclusion, short-term venetoclax in combination with FLA-IDA represents an effective treatment regimen in R/R AML identifying chemosensitive patients rapidly and inducing MRD negative remission in a high proportion of R/R AML patients.