Venetoclax-based salvage therapy in patients with relapsed/refractory acute myeloid leukemia previously treated with FLT3 or IDH1/2 inhibitors.

FLT3, IDH1 and IDH2 inhibitors as well as venetoclax in combination with hypomethylating agents or low-dose cytarabine have expanded treatment options for patients with acute myeloid leukemia (AML). However, little data exist on the efficacy of venetoclax-based therapies in AML patients previously treated with FLT3 or IDH1/2 inhibitors. In this multicenter, retrospective cohort study, we included 44 patients who received venetoclax-based therapy after FLT3, IDH1 or IDH2 inhibitors. The overall response rate (ORR; composite of complete remission [CR]/CR with incomplete count recovery, partial remission, and morphologic leukemia free state) was 56.8% (18.2% CR) and a median overall survival of 9.2 months. While 6 out of 7 patients with IDH1 mutations who had previously been treated with ivosidenib responded to venetoclax-based therapy, FLT3- ITD mutations were associated with a lower response rate. Our data suggest that venetoclax can be an effective salvage therapy in patients previously treated with IDH1/2 or FLT3 inhibitors.