Real-world data on tolerability and clinical response of cemiplimab in patients with advanced cutaneous squamous cell carcinoma: A retrospective, multicentre cohort study from the Netherlands

AbstractBackground Cutaneous squamous cell carcinoma (CSCC) is the second most common cutaneous malignancy and patients with advanced disease have a poor prognosis. Phase I/II clinical studies have shown the efficacy of cemiplimab, a monoclonal anti-PD-1 antibody, for this disease. However, real-world data on tolerability and clinical outcome in larger patient populations is needed to aid clinical decision-making. Methods In this retrospective cohort study, patients treated with flat dose cemiplimab 350 mg Q3W intravenously for advanced CSCC (aCSCC) from three centers in the Netherlands were retrospectively investigated. Adverse events (AE), tumor response, progression-free survival (PFS) and overall survival (OS) were assessed. Results In total, 65 patients (median age 76; range 30–93 years) with locally advanced (29 patients 45%) or metastatic (36 patients 55%) CSCC were included. All but 8 patients (88%) had comorbidities and 58 patients (89%) did not receive any prior systemic therapy. Treatment was well-tolerated, with grade 3–4 AEs in 22% of patients. An objective response was seen in 34 patients (52%), of whom 14 (22%) reached a complete response. With a median follow-up of 21.5 months, the median PFS was 10.9 (95% CI, 1.8–20.0) and median OS was 26.1 months. Conclusions In this real-world cohort of aCSCC patients from the Netherlands, cemiplimab demonstrated to be well-tolerated, even in elderly patients with severe comorbidities, achieving an objective response in 52% of patients. This outcome was comparable to the results of prospective clinical trials.