Final analysis of a phase 2 study of neoadjuvant cemiplimab for stage II to IV cutaneous squamous cell carcinoma

A multinational phase 2 trial evaluated neoadjuvant cemiplimab for resectable stage II to IV cutaneous squamous cell carcinoma (CSCC). A total of 79 patients received up to 4 doses of neoadjuvant cemiplimab 350 mg intravenously ever 3 weeks, followed by curative-intent surgery. Primary analysis of the trial found a pathologic complete response (pCR) rate of 51%, and a 12-months event-free survival (EFS) rate of 89%, with 11 EFS events. Final analysis of the trial has now been reported. At a median follow-up of 54 months, 16 EFS events had occurred. The five new EFS events were all comorbidity-related deaths without CSCC recurrence. The estimated 54-month EFS rate was 76.2%. Among 40 patients with pCR, none had experienced disease recurrence. Overall estimated 54-months overall survival (OS) rate was 79.4%. No new grade ≥ 3 treatment-emergent adverse events occurred. The authors conclude that this final analysis demonstrates durable EFS and OS, no late recurrences, and no new safety signals with neoadjuvant cemiplimab for CSCC.