FDA Approves Libtayo for Adjuvant Treatment of High-Risk CSCC

The FDA has approved cemiplimab-rwlc (Libtayo, Regeneron) for the adjuvant treatment of adults with cutaneous squamous cell carcinoma (CSCC) at high risk of recurrence following surgery and radiation, according to a statement from the agency.

The October 8, 2025, approval marks the first immunotherapy authorized for use in this post-surgical setting. Data from the randomized, placebo-controlled C-POST trial supported the approval, which enrolled 415 patients with high-risk CSCC. Median disease-free survival (DFS) was not reached in the cemiplimab group, compared to 49.4 months in the placebo arm (HR, 0.32; 95% CI, 0.20–0.51; P < 0.0001).

Patients received 350 mg every three weeks for 12 weeks, followed by either 700 mg every six weeks or 350 mg every three weeks, for up to 48 weeks or until recurrence or toxicity. Safety labeling includes warnings for immune-mediated events and embryo-fetal toxicity.

Source: FDA statement. October 8, 2025.