The U.S. Food and Drug Administration (FDA) has approved Regeneron Pharmaceuticals’ Libtayo® (cemiplimab-rwlc) as the first adjuvant immunotherapy for adult patients with cutaneous squamous cell carcinoma (CSCC) at high risk of recurrence following surgery and radiation. The approval marks a significant milestone in the treatment of CSCC, one of the most common forms of skin cancer in the U.S.
The decision followed a Priority Review by the FDA, reserved for therapies that offer substantial advances in treatment. Libtayo is now the only approved immunotherapy for patients in the adjuvant setting for CSCC—a group with historically poor outcomes and limited post-surgical treatment options.
“Patients whose CSCC is at a high risk of recurrence following surgery and radiation often have the poorest outcomes,” said Dr. Vishal A. Patel of George Washington University School of Medicine. “Until now, we lacked options to help prevent a devastating recurrence. As the first and only immunotherapy approved in this setting, Libtayo represents a practice-changing opportunity backed by compelling data.”
The FDA’s decision was supported by data from the pivotal Phase 3 C-POST trial, which evaluated Libtayo as an adjuvant therapy versus placebo. Results published in the New England Journal of Medicine and presented at the 2025 ASCO Annual Meeting showed that Libtayo reduced the risk of disease recurrence or death by 68% compared to placebo (hazard ratio: 0.32; 95% CI: 0.20–0.51; p<0.0001).
Libtayo’s safety profile in this new indication remains consistent with its established use in advanced cancers. Common side effects included rash, pruritus (itching), and hypothyroidism. Serious adverse events occurred in 18% of patients receiving the drug, with pneumonia, rash, and adrenal insufficiency reported in 1.5% or more of patients.
“This approval provides patients with CSCC at high risk of disease recurrence a much-needed option, as Libtayo is the only immunotherapy to demonstrate efficacy in this setting,” said Dr. George D. Yancopoulos, Regeneron’s President and Chief Scientific Officer. “Now with five FDA-approved indications, Libtayo is firmly established as a strong and versatile PD-1 inhibitor for patients with a variety of cancers.”
Samantha R. Guild, President of AIM at Skin Cancer Foundation, called the approval “wonderful news” for patients and praised Regeneron for its long-standing focus on non-melanoma skin cancer research.
To support patient access, Regeneron has also launched Libtayo Surround™, a program offering financial assistance and educational resources. Patients can learn more by calling 1-877-LIBTAYO.
A regulatory application for Libtayo in the same indication is currently under review in the European Union, with a decision expected in the first half of 2026.