CME Part I: Immune checkpoint inhibitors to treat cutaneous malignancies.
As the incidence of cutaneous malignancies continue to rise and their treatment with immunotherapy expands, dermatologists and their patients are more likely to encounter these agents. While blockade of immune checkpoint target proteins (CTLA-4, PD-1, PD-L1) generates an anti-tumor response in a substantial fraction of patients, there is a critical need for reliable predictive biomarkers, as well as approaches to address refractory disease. This article reviews the indications, efficacy, safety profile and evidence supporting checkpoint inhibition as therapeutics for metastatic melanoma, cutaneous squamous cell carcinoma, and Merkel cell carcinoma. Pivotal studies resulting in the approval of ipilimumab, pembrolizumab, nivolumab, cemiplimab and avelumab by regulatory agencies for various cutaneous malignancies, as well as ongoing clinical research trials, are discussed.