SELLAS Exceeds Target ORR in Trial, Surpasses Survival Benchmark for AML Patients.

SELLAS Life Sciences Group announced positive results from its Trial Exceeded Target Overall Response Rate (ORR) of 20%, with 44% response rate among patients with acute myeloid leukemia-myelodysplasia-related changes (AML MR) treated at the optimal dose of 30 mg twice a week. Median overall survival (mOS) of 8.9 months in patients with AML MR and 8.8 mOS in relapsed or refractory to venetoclax-based regimens exceeded the historical benchmark of 2.4 months. The FDA recommends advancing the trial to include newly diagnosed first-line AML patient cohorts, with enrollment expected to begin by Q1 2026.

Title: SELLAS Life Sciences Group Announces Positive Phase 2 Trial Results for SLS009 in AML

SELLAS Life Sciences Group, Inc. (NASDAQ: SLS) has reported positive results from its Phase 2 trial of SLS009 (tambiciclib), a highly selective CDK9 inhibitor, in relapsed/refractory acute myeloid leukemia (r/r AML). The trial exceeded the target overall response rate (ORR) of 20%, with a 44% response rate among patients with acute myeloid leukemia-myelodysplasia-related changes (AML MR) treated at the optimal dose of 30 mg twice a week (BIW). The median overall survival (mOS) of 8.9 months in patients with AML MR and 8.8 mOS in relapsed or refractory to venetoclax-based regimens exceeded the historical benchmark of 2.4 months.

The FDA has recommended advancing the trial to include newly diagnosed first-line AML patient cohorts, with enrollment expected to begin by Q1 2026. The trial preparation is underway, and the study will include two groups: a predictive biomarker cohort for newly diagnosed patients unlikely to benefit from standard aza/ven therapy based on molecular profiling, and an early resistance cohort for patients who initiate treatment with aza/ven but demonstrate confirmed lack of any response after two treatment cycles.

SELLAS' Chief Development Officer, Dragan Cicic, MD, stated, "Following constructive FDA guidance, we are preparing the trial focused on newly diagnosed AML patients as well as those early refractory to venetoclax and azacitidine. The study will include two groups – one comprising patients predicted not to benefit from standard aza/ven, based on cytogenetic risk factors, and a second comprising patients who begin aza/ven treatment but demonstrate confirmed resistance after two cycles. We believe earlier intervention with SLS009 may offer greater clinical benefit before patients’ bone marrow reserve is depleted by disease or prior therapies, and before the disease evolves into more resistant and aggressive forms."

SELLAS' President and Chief Executive Officer, Angelos Stergiou, MD, ScD h.c., commented, "AML remains an area of urgent unmet medical need, particularly for patients with relapsed or refractory disease, where standard treatments are often ineffective and poorly tolerated. What sets SLS009 apart is its consistent efficacy across a broad range of molecular subtypes. The remarkable response rates of 44% among AML MR patients, 50% among ASXL1-mutated AML MR, and 50% among M4/M5 patients at the optimal 30 mg BIW dose far exceed the targeted 20% benchmark. We saw a clear survival benefit with median OS reaching 8.8 months in patients refractory to venetoclax-based regimens in the cohort of patients with median 1 prior line of therapy, surpassing the historical median of 2.4 months and 4.1 months in cohorts with median 2 lines of prior therapy, versus 1.8 months reported in similar patient population. The treatment was also well-tolerated, with no dose-limiting toxicities across any treatment arm, validating both the biological selectivity and safety profile of our approach. We believe these data strongly support the potential of SLS009 to meaningfully extend life in patients with otherwise limited options, and we look forward to sharing these findings in more detail in the future."

References
[1] https://www.globenewswire.com/news-release/2025/07/15/3115485/0/en/SELLAS-Meets-All-Primary-Endpoints-in-Phase-2-Trial-of-SLS009-in-r-r-AML-and-Receives-FDA-Guidance-to-Advance-into-First-Line-Therapy-Study.html