Efficacy of Cemiplimab as Adjuvant or Neoadjuvant Therapy in the Treatment of Cutaneous Squamous Cell Carcinoma

Introduction Cutaneous squamous cell carcinoma (cSCC) is the second most common skin cancer in the White population. Unfortunately, the prognosis of advanced cSCC is poor, and management can be challenging. Until recently, the choice of systemic medications was limited, and those that were available had modest efficacy. Cemiplimab is an anti–programmed cell-death protein 1 inhibitor and the first immunotherapeutic agent approved for the treatment of metastatic or locally advanced cSCC. The purpose of this study was to evaluate the efficacy of cemiplimab when used as adjuvant or neoadjuvant therapy in patients treated at our institution. Methods A retrospective review of patients with locally advanced or metastatic cSCC who were treated with cemiplimab as adjuvant or neoadjuvant therapy at a single institution between February 2019 and November 2022 was performed. Response to treatment was objectively assessed based on Response Evaluation Criteria in Solid Tumors, version 1.1, criteria. The primary end point was objective response rate. Secondary endpoints included time to observed response, disease-control rate, progression-free survival, overall survival, and adverse effects of therapy. Results A total of 6 patients were identified with a median age of 79 years (range, 51–90 years). Four patients had locally advanced cSCC, and 2 had distant metastasis. Cemiplimab was used as adjuvant therapy in 3 patients and neoadjuvant therapy in 2 patients. There was 1 patient in which it was used for limb salvage, who would have otherwise required an amputation. Objective response rate, complete response, and partial response were 66% (4 of 6), 33% (2 of 6), and 33% (2 pf 6), respectively. Average time to observed response was 2.9 months. Disease-control rate was 83% (5 of 6), and average progression-free survival was 10 months. Toxicity was reported in 2 patients, both of which were grade 1 severity. Conclusions Cemiplimab has established its utility in the treatment of advanced cSCC, demonstrating clinical efficacy while generally having a tolerable adverse effect profile. Our preliminary results suggest that cemiplimab has potential as an adjuvant or neoadjuvant therapy in combination with surgery for treatment of cSCC.