Cutaneous squamous cell carcinoma (CSCC) is one of the most common human malignancies, and the incidence is increasing with time. High mutational loads, known infiltration with lymphocytes, and programmed death (PD)-ligand 1 (PD-L1) expression suggest that immune checkpoint inhibitors, such as PD-1 inhibitors, may show utility in treating CSCC, similar to response see in other solid tumor types. Recently, the robust responsiveness of CSCCs to the PD-1 inhibitor cemiplimab was revealed in the results of a combined phase I/II clinical trial, with an overall response rate of 50% and a durable response exceeding 6 months in 57% of responders. Compared to prior systemic therapies with scant data for efficacy and safety, cemiplimab is a breakthrough therapy, the first systemic drug approved for advanced CSCCs. Other immune checkpoint inhibitors have shown promise through case reports and series, and are currently in clinical development for CSCCs.
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No external funding was used in the preparation of this manuscript.
Conflict of interest
Anne Lynn S. Chang has received research grants from Regeneron and Merck, and was an advisory board member for Regeneron and Merck. Roma Patel declares that she has no conflicts of interest that might be relevant to the contents of this article.
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Patel, R., Chang, A.L.S. Immune Checkpoint Inhibitors for Treating Advanced Cutaneous Squamous Cell Carcinoma. Am J Clin Dermatol 20, 477–482 (2019). https://doi.org/10.1007/s40257-019-00426-w