Cosibelimab: A Novel Therapeutic for Advanced Cutaneous Squamous Cell Carcinoma.

Cutaneous squamous cell carcinoma (cSCC) is the second most common skin cancer worldwide. Treatments of locally advanced cSCC (laCSCC) and metastatic cSCC (mCSCC) have been evolving with the introduction of immunotherapies, which target the programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1) pathway. Recently, cosibelimab was the first PD-L1 antibody approved by the United States Food and Drug Administration for the treatment of patients with laCSCC or mCSCC who are not candidates for curative surgery or radiation. Cosibelimab not only offers blockade of PD-L1 but also induces antibody-dependent cellular cytotoxicity. In its pivotal clinical trial, the objective response rate for patients with mCSCC treated with cosibelimab was 47.4%. Due to the different mechanisms of action, differences have been noted in the safety between PD-1 inhibitors and PD-L1 inhibitors, with PD-L1 inhibitors having a lower occurrence of Grade 3 or higher treatment-related adverse events, including immune-related adverse events. Additional real-world studies are needed to further evaluate its efficacy and safety. Cosibelimab is a novel immune checkpoint inhibitor and represents a promising therapeutic option for patients with advanced cSCC.