# Prolonged Responses to Cemiplimab in Advanced Cutaneous Squamous Cell Carcinoma: A Case Series

## TL;DR

This case series shows that cemiplimab can lead to long-lasting responses in older patients with advanced skin cancer, even after treatment stops.

## Contribution

The study demonstrates prolonged responses and potential rechallenge success with cemiplimab in advanced cutaneous squamous cell carcinoma.

## Key findings

- Four patients with advanced CSCC achieved complete responses to cemiplimab with time to response ranging from 6 to 24 months.
- Only one patient experienced a local relapse after treatment discontinuation, and cemiplimab rechallenge controlled the disease.
- Immune-related adverse events occurred in two patients but were effectively managed.

## Abstract

Cutaneous squamous cell carcinoma (CSCC) is a common skin malignancy with a subset of cases presenting as locally advanced or metastatic disease, often in elderly or comorbid patients. Cemiplimab, an anti-PD-1 antibody, has emerged as a standard treatment for advanced CSCC. This case series presents real-world outcomes of four patients (aged 75 to 83) with advanced CSCC treated with cemiplimab. Two patients had previous disease progression on first-line chemotherapy treatment. All four achieved complete responses, with time to response ranging from 6 to 24 months. Immune-related adverse events occurred in two cases, but were effectively managed. Cemiplimab was discontinued in all patients after sustained responses. Only one patient presented with a local relapse within 2 years after stopping treatment, after which cemiplimab was rechallenged with subsequent disease control. This case series highlights the significant and lasting responses that can be achieved with cemiplimab in advanced CSCC, even in older patients with comorbidities or prior treatment failure. Sustained disease control after treatment discontinuation favors time-limited immunotherapy and, in selected patients, cemiplimab rechallenge may represent a viable therapeutic option upon relapse.