Sellas Life Sciences Group Inc. announced positive results from its ongoing Phase 2 study evaluating SLS009, a selective CDK9 inhibitor, in combination with azacitidine (AZA) and venetoclax (VEN) for patients with relapsed or refractory acute myeloid leukemia with myelodysplastic syndrome-related changes (AML-MR) following prior VEN-based treatment. The results, presented at the 67th American Society of Hematology $(ASH)$ Annual Meeting in December 2025, showed a 46% overall response rate across all cohorts and a 58% overall response rate in patients with one prior line of therapy. The combination was reported to be safe and feasible, with no dose-limiting toxicities observed. The company plans to expand the study to evaluate SLS009 plus AZA/VEN in newly diagnosed AML with high-risk features in the first quarter of 2026.