Adjuvant Cemiplimab: New Standard for High-Risk CSCC Recurrence

The C-POST phase 3 clinical trial (NCT03969004) has demonstrated that adjuvant cemiplimab (Libtayo) significantly reduces disease recurrence in patients with high-risk cutaneous squamous cell carcinoma (CSCC) following definitive local therapy consisting of surgery and postoperative radiation therapy). In an interview with Targeted Oncology, Danny Rischin, MD, MBBS, FRACP, director of Medical Oncology at the Peter MacCallum Cancer Center in Melbourne, Australia, discusses the findings and implications.

Cemiplimab is already the standard of care for advanced CSCC, but this trial marks its first successful demonstration as an adjuvant systemic treatment for patients at high risk of recurrence. The treatment showed a statistically significant and clinically meaningful improvement in disease-free survival (DFS) and freedom from locoregional and distant recurrence, with an acceptable safety profile consistent with its known monotherapy profile. These findings suggest a new standard of care for this specific high-risk patient population, aiming to prevent recurrences and reduce associated morbidity.

Prior to this trial, there was no approved systemic treatment for patients with CSCC at high risk of recurrence after definitive local therapy. Patients in this group face a very high risk of recurrence with risk of considerable disfigurement and morbidity from locoregional recurrences.

The improvements seen in C-POST are considered statistically significant and clinically meaningful, promising to prevent these recurrences and help patients avoid having to go through experience of further treatment later.

This article was generated with assistance from NotebookLM. It was edited and reviewed by Targeted Oncology staff. If you have any questions about the use of AI, please contact us.

REFERENCE:

Rischin D, Porceddu SV, Day F, et al. Phase 3 trial of adjuvant cemiplimab (cemi) versus placebo (pbo) for high-risk cutaneous squamous cell carcinoma (CSCC). J Clin Oncol. 43,16_suppl. doi:10.1200/JCO.2025.43.16_suppl.6001