By Fineline Cube 
Regeneron Pharmaceuticals, Inc. (NASDAQ: REGN) announced the European Commission (EC) approved Libtayo (cemiplimab) as adjuvant therapy for adult patients with high‑risk cutaneous squamous cell carcinoma (CSCC) post‑surgery and radiation, expanding the EU indication to include recurrence‑risk patients following the same FDA approval in October 2025.
Regulatory Milestone
| Item | Detail |
|---|---|
| Product | Libtayo (cemiplimab) |
| Company | Regeneron Pharmaceuticals (NASDAQ: REGN) |
| Agency | European Commission (EC) |
| Approval Type | Adjuvant indication expansion |
| Indication | Adult patients with CSCC at high risk of recurrence after surgery and radiation |
| Previous Approval | U.S. FDA approved same indication, Oct 2025 |
| Trial Basis | Phase III C‑POST study |
Clinical Evidence – C‑POST Phase 3 Trial
| Endpoint | Result vs Placebo |
|---|---|
| Primary: Disease recurrence or death | 68% risk reduction (HR 0.32; 95% CI: 0.20‑0.51; p<0.0001) |
| Population | CSCC patients at high risk post‑surgery/radiation |
| Safety Profile | Consistent with prior Libtayo reports; no new safety signals |
Commercial & Strategic Impact
- Market Expansion: Adjuvant CSCC represents a ~15,000‑20,000 patient opportunity annually in the EU5, where Libtayo is now positioned as the first PD‑1 inhibitor approved in this setting.
- Revenue Boost: Analysts project adjuvant CSCC could add $200‑350 million to Libtayo’s peak global sales, complementing its ~$1.5 billion run‑rate in advanced CSCC and other indications.
- Competitive Moat: First‑mover advantage in adjuvant CSCC creates barrier for Keytruda and Opdivo, which lack pivotal data in this niche.
- Execution: Regeneron will leverage existing EU commercial infrastructure; launch expected Q1 2026 with focused oncology outreach.
Forward‑Looking Statements
This brief contains forward‑looking statements regarding Libtayo’s commercial performance, market penetration, and regulatory status. Actual results may differ due to competitive dynamics, reimbursement negotiations, and patient adoption rates.-Fineline Info & Tech