Study summary

Immunotherapy after surgery and radiation cut the risk of recurrence by two-thirds

C-POST trial · 415 people, phase 3 · Published May 2025, New England Journal of Medicine; FDA approved October 2025

87.1%disease-free at 24 months, vs 64.1% with placebo

What was tested

Cemiplimab, a PD-1 immunotherapy, for up to 48 weeks after surgery and radiation, against placebo, for cutaneous squamous cell carcinoma at high risk of coming back.

What they found

24-month disease-free survival was 87.1% vs 64.1% (hazard ratio 0.32).
Local recurrence fell sharply (9 vs 40 events) and distant recurrence was also lower.
Severe side effects were more common (23.9% vs 14.2%).

What it means

The first immunotherapy approved after surgery for skin squamous cell cancer.

N Engl J Med, via PubMed ↗ ← Back to the outlook

Last reviewed 2026-11-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.