Multicenter phase 1 trial of dual CTLA-4 checkpoint blockade with PD-1 checkpoint blockade for advanced solid tumors

CS1002 is a novel anti-CTLA-4 monoclonal antibody and CS1003 (aka nofazinlimab) is a novel anti-PD-1 monoclonal antibody. A first-in-human phase 1 study at nine centers in Australia and China evaluated CS1002 with or without CS1003 in patients with advanced solid tumors. There were nod dose-limiting toxicities, and no maximum tolerated doses were established. In dose expansion (n=61), treatment-related adverse events were seen in 75%, and grade ≥3 TRAEs in 18.3%. Among patients evaluable for efficacy, objective responses were seen in 37.7% of patients. The authors conclude that CS1002, as monotherapy and in combination with CS1003, had a manageable safety profile and promising antitumor activity. These results support further evaluation of this combination for solid tumors.