Neoadjuvant Cemiplimab for Stage II to IV Cutaneous Squamous-Cell Carcinoma

N Engl J Med. 2022 Oct 27;387(17):1557-1568. doi: 10.1056/NEJMoa2209813. Epub 2022 Sep 12.


Background: In a pilot study involving patients with cutaneous squamous-cell carcinoma, a high percentage of patients had a pathological complete response with the use of two doses of neoadjuvant cemiplimab before surgery. Data from a phase 2 study are needed to confirm these findings.

Methods: We conducted a phase 2, confirmatory, multicenter, nonrandomized study to evaluate cemiplimab as neoadjuvant therapy in patients with resectable stage II, III, or IV (M0) cutaneous squamous-cell carcinoma. Patients received cemiplimab, administered at a dose of 350 mg every 3 weeks for up to four doses, before undergoing surgery with curative intent. The primary end point was a pathological complete response (the absence of viable tumor cells in the surgical specimen) on independent review at a central laboratory, with a null hypothesis that a pathological complete response would be observed in 25% of patients. Key secondary end points included a pathological major response (the presence of viable tumor cells that constitute ≤10% of the surgical specimen) on independent review, a pathological complete response and a pathological major response on investigator assessment at a local laboratory, an objective response on imaging, and adverse events.

Results: A total of 79 patients were enrolled and received neoadjuvant cemiplimab. On independent review, a pathological complete response was observed in 40 patients (51%; 95% confidence interval [CI], 39 to 62) and a pathological major response in 10 patients (13%; 95% CI, 6 to 22). These results were consistent with the pathological responses determined on investigator assessment. An objective response on imaging was observed in 54 patients (68%; 95% CI, 57 to 78). Adverse events of any grade that occurred during the study period, regardless of whether they were attributed to the study treatment, were observed in 69 patients (87%). Grade 3 or higher adverse events that occurred during the study period were observed in 14 patients (18%).

Conclusions: Neoadjuvant therapy with cemiplimab was associated with a pathological complete response in a high percentage of patients with resectable cutaneous squamous-cell carcinoma. (Funded by Regeneron Pharmaceuticals and Sanofi; number, NCT04154943.).

Publication types

  • Clinical Trial, Phase II
  • Multicenter Study

MeSH terms

  • Antineoplastic Agents, Immunological / administration & dosage
  • Antineoplastic Agents, Immunological / adverse effects
  • Antineoplastic Agents, Immunological / therapeutic use
  • Antineoplastic Combined Chemotherapy Protocols / administration & dosage
  • Antineoplastic Combined Chemotherapy Protocols / adverse effects
  • Antineoplastic Combined Chemotherapy Protocols / therapeutic use
  • Carcinoma, Squamous Cell* / drug therapy
  • Carcinoma, Squamous Cell* / pathology
  • Carcinoma, Squamous Cell* / surgery
  • Humans
  • Neoadjuvant Therapy*
  • Neoplasm Staging
  • Pilot Projects
  • Remission Induction
  • Skin Neoplasms* / drug therapy
  • Skin Neoplasms* / pathology
  • Skin Neoplasms* / surgery


  • cemiplimab
  • Antineoplastic Agents, Immunological

Associated data