Post-transplant sorafenib effectively prevents relapse in FLT3-mutated acute myeloid leukemia

Almost 50% of patients with FLT3-ITD AML relapse despite undergoing allogeneic hematopoietic stem cell transplantation (HSCT). FLT-3 inhibitors (FLT3i) can be used in a post-HSCT setting as a relapse prevention.

We retrospectively compared 24 FLT3-mutated AML patients receiving post-HSCT SORA with a control group of 24 FLT3-mutated AML SORA-free individuals. SORA was initiated at a median of 2.9 months after transplantation. Median dosage was 600 mg daily with median treatment duration of 8.8 months. Due to toxicities, 16/24 patients required dose modifications with 6 early SORA withdrawals. After median follow-up of 20.7 months, 1 patient relapsed in SORA-group whereas 9 relapses were observed in the control group (p=0.004).

SORA maintenance significantly improved OS and RFS probability when compared to the control group (36.3 vs 11.6 months; p = 0.01 and 95.5% and 66.7%; p = 0.004; respectively). SORA maintenance effectively reduced the risk of death by 93.6% for patients in complete remission with detectable measurable residual disease (p = 0.001). At the last follow-up, 4.2% of patients died in SORA-group when compared with 50% in the control group (p < 0.001).

SORA maintenance after HSCT diminishes the cumulative incidence of relapse as well as prolongs OS and RFS in FLT3-mutated AML.