Multinational phase 1 study of cosibelimab for metastatic cutaneous squamous cell carcinoma

PD-1 blocking antibodies are approved to treat metastatic cutaneous squamous cell carcinoma (mCSCC) in patients ineligible for curative surgery or radiation. Some patients experience inadequate responses or severe immune-related adverse event, indicating the need for improved therapies. Cosibelimab (CK-301) is an investigational high-affinity PD-L1 blocking antibody. A multinational phase 1 study found meaningful responses of mCSCC to cosibelimab. Median duration of response was not reached after median follow-up of 15.4 months, with response ongoing in 73.0% of responders. The safety profile was manageable.