Sellas Reports Preclinical Evidence for CDK9 Inhibitor SLS009 in Pancreatic Cancer

Sellas Life Sciences Group Inc. (NASDAQ: SLS) presented preclinical findings at the American Association for Cancer Research Conference on Pancreatic Cancer, suggesting that its CDK9 inhibitor SLS009 may enhance treatment efficacy when combined with RAS inhibitors in MYC-amplified pancreatic ductal adenocarcinoma. The study focused on patient-derived organoid models resistant to daraxonrasib, a recently approved RAS inhibitor, demonstrating that SLS009 alone induced modest apoptosis (17.9%) and necrosis (14.5%) at 200 nanomolar concentration after 72 hours. When paired with daraxonrasib at 100 nanomolar, the combination yielded significantly higher rates of cell death—36.5% apoptosis and 30.6% necrosis—compared to either agent alone. Additionally, combining SLS009 with ZEN3694, a BET inhibitor, further amplified cytotoxic effects, while also sustaining suppression of MYC RNA and reducing protein expression of MYC and MCL-1, markers linked to cancer progression. Dragan Cicic, Senior Vice President of Clinical Development at Sellas, noted that these results offer ‘encouraging preclinical evidence’ that CDK9 inhibition could improve outcomes for patients with RAS-resistant pancreatic cancer, where MYC amplification is a known mechanism of resistance.