Real-World Treatment Patterns and Outcomes of Cemiplimab in Patients with Advanced Cutaneous Squamous Cell Carcinoma Treated in US Oncology Practices.

Background: Prior to the Food and Drug Administration approval of cemiplimab in 2018, the median overall survival (OS) for adult patients with advanced CSCC receiving systemic therapy was approximately 8 to 15 months. Limited real-world data are available on cemiplimab for this indication in the US. Patients and Methods: This retrospective cohort study included US patients with advanced CSCC initiating cemiplimab monotherapy in a real-world database (2018-2021). A clinical trial-like sub-cohort was identified using select criteria. Time to treatment discontinuation (TTD), time to next treatment (TTNT), and OS were estimated using Kaplan-Meier methods. Cox proportional hazard models were used to examine prognostic factors associated with OS in the main cohort. Results: The main cohort included 622 patients (n = 240 in the trial-like cohort). In the main cohort, the median age was 78 years, 77.8% were male, 21.4% were immunocompromised/immunosuppressed, and 63.8% had metastatic CSCC. Median (95% CI) TTD and TTNT were 8.0 (6.6-9.0) months and 16.4 (13.3-21.0) months, respectively, in the main cohort. Median (95% CI) OS was 24.8 (21.8-29.1) months in the main cohort (not reached in the trial-like cohort). In multivariable analyses, age <60 years (hazard ratio [HR], 0.37), Eastern Cooperative Oncology Group performance status <3-4 (HR range, 0.13-0.57), and primary CSCC location in the head and neck only versus extremities only (HR, 0.59) were associated with better OS. Similar OS was observed between patients who had immunosuppressing/immunocompromising conditions and those without. Conclusion: These findings confirm the effectiveness of cemiplimab among a heterogenous, real-world advanced CSCC patient population and substantiate the efficacy of cemiplimab observed in clinical trials.