Immunotherapy Approved for Preventing Recurrence of Certain Skin Cancers

The FDA approved cemiplimab-rwlc as an adjuvant therapy for patients with cutaneous squamous cell carcinoma at high risk of recurrence.

The U.S. Food and Drug Administration (FDA) has approved cemiplimab-rwlc (Libtayo) for use after surgery and adjuvant radiation in adult patients with cutaneous squamous cell carcinoma (CSCC) that has a high risk of recurring.

Cemiplimab-rwlc is a monoclonal antibody that belongs to a class of immunotherapies called immune checkpoint inhibitors. By binding to the human programmed death receptor-1 (PD-1) on T cells, cemiplimab-rwlc prevents suppression of T-cell activity by blocking PD-1 from binding to the PD-L1 and PD-L2 receptors on tumor and other cells.

The FDA first approved cemiplimab-rwlc in 2018 as a treatment for patients with CSCC who are not eligible for curative surgery and radiation, specifically those with metastatic disease or certain locally advanced cases. The latest approval allows cemiplimab-rwlc to be used in patients with earlier stages of CSCC who are eligible for curative surgery and radiation as a strategy to reduce the risk of the disease coming back. It is the first adjuvant immunotherapeutic approved to help prevent the recurrence of high-risk CSCC. Cemiplimab-rwlc was also previously approved to treat advanced non-small cell lung cancer and metastatic basal cell carcinoma, another non-melanoma form of skin cancer.

This new approval is based on results from the C-POST clinical trial. The randomized, double-blind, multicenter, placebo-controlled phase III trial evaluated 415 adult patients with CSCC who had a high risk of recurrence after surgery and adjuvant radiation. Patients were randomly assigned (1:1) to receive either cemiplimab-rwlc or a placebo.

Patients treated with the placebo were at 68% greater risk of cancer recurrence than patients treated with cemiplimab-rwlc. During the approximately 60 months of follow-up, 12% of patients in the cemiplimab-rwlc arm experienced disease progression or death, compared with 32% of those in the placebo arm.

The recommended dosage for cemiplimab-rwlc as an injectable adjuvant therapy for patients with high risk of CSCC recurrence after surgery and adjuvant radiation is as follows:

  • Either 350 mg once every three weeks for 12 weeks followed by 700 mg every six weeks until disease recurrence, unacceptable toxicity, or up to 48 weeks;

Or

  • 350 mg every three weeks until disease recurrence, unacceptable toxicity, or up to 48 weeks.

CSCC is one of the most common forms of skin cancer and is associated with a high rate of survival when detected early. While most early-stage CSCCs can be completely removed by surgical excision or ablation, a subset of these tumors recur after removal, with recurrence frequency ranging between 3% and 23%.

The FDA rendered its decision on October 8, 2025. Check this resource for updated information on all therapeutics regulated by the FDA.