Regeneron's Libtayo Secures FDA Approval for Adjuvant Treatment of High-Risk Cutaneous Squamous Cell Carcinoma

Regeneron Pharmaceuticals has achieved a significant milestone as its cancer immunotherapy drug Libtayo (cemiplimab) received FDA approval for the adjuvant treatment of patients with cutaneous squamous cell carcinoma (CSCC) who are at high risk of recurrence following surgery and radiation. This latest development marks Libtayo as the first immunotherapy to receive such an indication, potentially changing the treatment landscape for this common form of skin cancer.

Expanding Libtayo's Reach in CSCC

Libtayo, a PD-1 inhibitor, initially gained FDA approval in 2018 for the treatment of patients with metastatic or locally advanced CSCC who are not candidates for curative surgery or radiation. The recent label expansion now allows for its use in the adjuvant setting, addressing a critical need for patients at high risk of disease recurrence.

Dr. Vishal Patel, professor of dermatology at George Washington University, emphasized the significance of this approval, stating, "Until now, we lacked options to help prevent a devastating recurrence and immunotherapy was only available for patients with advanced CSCC, who were no longer candidates for curative surgery or curative radiation." Dr. Patel described the label expansion as "practice-changing" for high-risk patients.

Clinical Trial Success and Market Implications

The FDA's decision was based on compelling results from a phase 3 trial, which demonstrated that Libtayo reduced the risk of disease recurrence or death by 68% compared to placebo at a median follow-up of 24 weeks. This success is particularly noteworthy given that Merck's competing PD-1 inhibitor, Keytruda, failed in a similar trial for adjuvant CSCC treatment last year.

Libtayo's latest approval is expected to further boost its market position. The drug achieved blockbuster status in 2024, with sales reaching $1.22 billion. In the second quarter of 2025, worldwide sales increased by 27% year-over-year to $377 million, indicating strong growth momentum.

Regeneron's Strategic Moves and Future Prospects

Regeneron's decision to acquire full rights to Libtayo from Sanofi for $900 million in 2022 appears to be paying dividends. The company is actively exploring Libtayo's potential in other indications, including a combination therapy with fianlimab for first-line melanoma treatment.

George Yancopoulos, M.D., Ph.D., Regeneron's Chief Scientific Officer, expressed optimism about ongoing studies, stating, "If these data confirm best-in-class activity in melanoma, it will increase our confidence for this combination in other cancer settings."

With approximately 1.8 million CSCC diagnoses annually in the U.S., accounting for about 20% of skin cancer cases, Libtayo's expanded label presents a significant market opportunity. Regeneron is also pursuing approval for this indication in Europe, with a decision expected in the first half of 2026.