Dr Gross on the Safety of Neoadjuvant Cemiplimab in Stage II/IV CSCC

Neil D. Gross, MD, FACS, surgeon-scientist, director, Clinical Research, the Department of Head and Neck Surgery, the University of Texas MD Anderson Cancer Center, discusses key safety data derived from additional follow-up of a phase 2 study (NCT04154943) evaluating neoadjuvant cemiplimab (Libtayo) in cutaneous squamous cell carcinoma (CSCC), as well as highlights the implications of these data for continued research.

The non-randomized, multicenter study, evaluated neoadjuvant cemiplimab followed by surgery with curative intent in patients with stage II-IV cutaneous CSCC. Subsequent treatment in part 2 of the study, which included up to 48 weeks of adjuvant cemiplimab, radiotherapy, or observation only, was determined by investigator discretion.

At a median follow-up of 18.7 months, the study revealed a 1-year event-free survival (EFS) rate with the cemiplimab regimen of 89.0% (95% CI, 79.1%-94.3%) in the overall population. Patients who achieved a pathologic complete response (pCR) following surgery had even more favorable outcomes, with a 12-month EFS of 94.9% (95% CI, 81.0%-98.7%) and no disease recurrence. Conversely, patients who did not undergo surgery or were non-responders demonstrated a lower estimated 12-month EFS of 72.0% (95% CI, 43.8%-87.7%).

Regarding safety, neoadjuvant cemiplimab was generally well tolerated, with 89% of patients experiencing a treatment-emergent adverse effect (TEAE) of any grade and 19% experiencing a TEAE of grade 3 or higher, Gross details. Among the 16 patients who received adjuvant cemiplimab per investigator discretion, there were 4 grade 3 TEAEs, including 2 grade 3 serious AEs of worsening cardiomyopathy and hypophysitis, he adds. Notably, no deaths related to the study drug occurred in this subgroup.

These findings, which were presented at the 2023 ESMO Annual Congress, suggest that the neoadjuvant approach with cemiplimab may be beneficial for patients with resectable CSCC, Gross states. The encouraging results warrant further investigation in a randomized phase 3 setting to establish its efficacy and safety as a standard treatment approach for this patient population, he concludes.