Real-World Response of Cemiplimab Immunotherapy for Treating Locally Advanced or Metastatic Cutaneous Squamous Cell Carcinoma in a Tertiary UK Oncology Centre.

Introduction: Cemiplimab has been licensed for use in the United Kingdom as the sole immunotherapy agent for first-line use in advanced cutaneous squamous cell carcinoma (a-cSCC). Given that previous clinical trials leading to the approval of cemiplimab had relatively small patient cohorts with relatively short follow-up periods, with a large proportion of patients who had received prior systemic treatment, this retrospective real-world study sought to add further insight into survival and toxicity in patients who exclusively had received first-line use of cemiplimab, as well as comparing response rates (RRs) based on primary site location. Methods: This retrospective study identified patients diagnosed with a-cSCC between 01/08/2019 and 31/03/2024 who received cemiplimab as first-line treatment at our institution. Data to enable response assessment and toxicity were collected and analyzed. Results: 50 patients were identified with a mean age of 75 years (range: 44-94). 78% ( Discussion: The use of cemiplimab as first-line treatment in a-cSCC demonstrates high efficacy and low rates of serious toxicity, which is especially reassuring in a patient cohort comprising of more elderly patients. The high complete RR seen in our patient cohort may reflect the exclusive first-line use of cemiplimab in our study, as per now established real-world practice in a-cSCC. Higher RRs and PFS are seen in patients with head/neck primary site of disease vs. non head/neck primary site, which should be evaluated further in future clinical trials.