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.