Arcus says new data demonstrated ‘best-in-class potential’ for casdatifan

Arcus Biosciences (RCUS) presented new data for casdatifan, a HIF-2a inhibitor with best-in-class potential, in an oral plenary session by Dr. Toni K. Choueiri, Dana-Farber Cancer Institute, at the 2025 American Society of Clinical Oncology Genitourinary Cancers Symposium. “ARC-20 is a Phase 1/1b dose-escalation and expansion study. New data include mPFS and ORR for the 50mg BID cohort, and ORR for the 50mg once-daily and 100mg QD cohorts, all of which evaluated casdatifan in patients with metastatic clear cell renal cell carcinoma, most of whom had progressed on at least two prior lines of therapy, including both an anti-PD-1 and a VEGFR tyrosine kinase inhibitor therapy. The patient population was heavily pretreated; more than half of subjects received at least three prior lines of therapy and approximately one quarter had received at least four prior lines of therapy. Most patients had an International Metastatic Renal Cell Carcinoma Database Consortium risk factor of intermediate or poor. Casdatifan showed improvement in primary progressive disease rate, ORR and mPFS relative to published data from studies with HIF-2a inhibitors to date. At the time of data cut off, January 3, 2025, most patients, 81-87%, experienced disease control with either a partial response or stable disease, and most were still on treatment. The median duration of response had not been reached, with all but two of the 26 responders across all three cohorts still on treatment. No unexpected safety signals were observed at the time of DCO, and casdatifan had an acceptable and manageable safety profile across all doses. Across all three cohorts, only one patient discontinued treatment as a result of anemia and only two due to hypoxia,” the company stated.