Hypomethylating agents-venetoclax as salvage therapy for relapse of AML and MDS after allogeneic HCT

Relapse after allogeneic hematopoietic cell transplantation (alloHCT) remains a challenge for patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS), and salvage therapy in this setting is not standardized. Given the efficacy of hypomethylating agents and venetoclax (HMA-VEN) in the frontline and relapsed settings, we evaluated the use of this therapy for post-alloHCT relapse. Eighty-three patients with AML (n = 69) or MDS (n = 14) who relapsed after alloHCT were included in this retrospective analysis. The median time to relapse after alloHCT was 7.0 months. Most patients (55%) had prior VEN exposure, and 28% of these patients had previously experienced treatment failure with a VEN-based regimen. HMA-VEN treatment-emergent toxicities were predominantly neutropenia and thrombocytopenia; however, the 30-day mortality was only 3.6%. There were 3 deaths within 30 days because of infectious complications. HMA-VEN led to a complete response (CR) or CR with incomplete hematological recovery in 48% of the patients, with 58% of these patients achieving minimal residual disease negativity. In multivariable analysis, European LeukemiaNet 2024 genetic risk stratification was a predictor of survival outcome. Additionally, prior VEN failure was not a predictor of overall survival. In conclusion, HMA-VEN provides an efficacious and well-tolerated option for post-alloHCT AML or MDS relapse regardless of their prior therapy and may allow responders to undergo a second alloHCT with curative intent.