Real-World Experience With Cemiplimab in Advanced Cutaneous Squamous Cell Carcinoma.

Background: Cutaneous squamous cell carcinoma (cSCC) is the second most common nonmelanoma skin cancer in Canada. However, few real-world reports exist on the treatment of refractory locally advanced (LA) and metastatic cSCC with cemiplimab to date.

Objectives: The objective of this study was to characterize the demographic and clinical outcomes of advanced cSCC patients on cemiplimab in a real-world setting.

Methods: Retrospective analysis of adult patients with refractory LA and metastatic cSCC treated with cemiplimab at the London Regional Cancer Program in Canada. Patient demographics and treatment characteristics were reported, as well as Kaplan-Meier estimates of progression-free survival (PFS) and overall survival (OS).

Results: Forty patients were included in this study. Sixteen (40%) had LA disease and 24 (60%) had metastatic disease. Median treatment duration was 3.5 months (range: 0.6-29.4 months). Kaplan-Meier analyses of the entire study population revealed that the median OS was not reached [NR; 95% confidence interval (CI) 9.1 months-NR], but median PFS was 11.5 months (95% CI 7.0 months-NR). A total of 25% of patients experienced at least one adverse event from cemiplimab. Reasons for treatment discontinuation were death from any cause (25%), disease progression (15%), cemiplimab adverse events (5%), and other causes (15%).

Discussion: The 12 month estimates of OS and PFS were lower than pivotal phase I and II clinical trials. However, toxicity was tolerable. Cemiplimab remains a safe and effective therapy in patients with refractory LA and metastatic cSCC disease.