- Libtayo® (cemiplimab) Phase 3 trial shows 68% reduction in disease recurrence or death risk for high-risk CSCC after surgery.
- Trial reveals 87% disease-free survival at two years with Libtayo compared to 64% with placebo.
- Regulatory applications submitted in the U.S. and EU for adjuvant CSCC treatment with Libtayo.
Regeneron Pharmaceuticals, Inc. (REGN, Financial) has announced significant findings from its Phase 3 C-POST trial involving the drug Libtayo® (cemiplimab) for patients with high-risk cutaneous squamous cell carcinoma (CSCC) following surgery. The trial, presented at the 2025 American Society of Clinical Oncology Annual Meeting and published in the New England Journal of Medicine, showed Libtayo reduced the risk of disease recurrence or death by an impressive 68% compared to placebo (HR: 0.32; p
Patients treated with Libtayo exhibited an 87% rate of disease-free survival (DFS) after two years, significantly higher than the 64% seen in those given a placebo. The treatment also demonstrated an 80% reduction in locoregional recurrence and a 65% reduction in distant recurrence risk. These results suggest a potential paradigm shift in managing high-risk CSCC.
The safety profile of Libtayo was manageable, although 24% of those in the Libtayo group experienced Grade ≥3 adverse events, compared to 14% in the placebo group. Common side effects included fatigue, rash, and diarrhea, which were consistent with PD-1 inhibitor effects.
Regulatory submissions have been filed in both the United States and European Union, positioning Libtayo as the first immunotherapy to show a statistically significant benefit in the adjuvant setting for high-risk CSCC. While already approved for other indications such as advanced basal cell carcinoma and non-small cell lung cancer, Libtayo is pending approval specifically for adjuvant treatment in high-risk CSCC.
