Patients with high-risk resectable cSCC who have yet to undergo definitive surgery will be eligible to enroll. Patients with nodal and/or in-transit relapse including those who have received prior adjuvant RT are eligible to enroll. This trial excludes patients who have received either nivolumab or pembrolizumab or other anti-PD-(L)1 therapy. Suitable patients will be identified pre-operatively. Patients will undergo a 28-day screening evaluation consisting of systemic staging scans, tumor biopsy, and blood studies to confirm suitability. Once enrolled, patients will receive pembrolizumab peri-operatively for 6 weeks (200mg Q3Wq3; 2 cycles) prior to definitive surgery (Neoadjuvant Phase). Following peri-operative therapy, patients will undergo restaging scans and surgical evaluation followed by definitive surgical resection (Surgical Phase). Post-operatively, patients will receive 15 further cycles of pembrolizumab over a 45-week period (200mg q3Q3W) (Adjuvant Phase). In the post-operative period, if patients are deemed eligible for RT, this will be administered concurrently with pembrolizumab. The total duration of pembrolizumab therapy is 1 year (52 weeks).
This phase II single-arm two-stage neoadjuvant study of pembrolizumab in patients with PD-1 naïve high-risk resectable cutaneous squamous cell carcinoma (cSCC) will be conducted over a 52-week period. The study will include patients who have not undergone surgery to remove disease, to formally evaluate whether both biologically and clinically high-risk disease may benefit from neoadjuvant anti-PD-1 therapy. Response to neoadjuvant anti-PD-1 therapy will be evaluated for association with improved landmark Relapse-free Survival (RFS).