# PD-1 inhibitor treatment outcomes for cutaneous squamous cell carcinoma in patients over 85: a comparative analysis

## TL;DR

PD-1 inhibitors like cemiplimab are effective and safe for treating skin cancer in patients over 85, though they have shorter overall survival due to other health issues.

## Contribution

This study provides evidence on the efficacy and safety of PD-1 inhibitors in very elderly patients with cutaneous squamous cell carcinoma.

## Key findings

- Patients over 85 had similar response and disease control rates to younger patients.
- Progression-free and cancer-specific survival were comparable across age groups.
- Overall survival was shorter in patients over 85, likely due to non-cancer causes.

## Abstract

Programmed-cell death protein 1 (PD-1) inhibitors have become standard of care in the treatment of advanced or metastatic cutaneous squamous cell carcinoma (cSCC). However, insufficient data exists regarding treatment outcomes and safety among elderly patients, including patients aged >85.

We retrospectively reviewed patients aged >85 (n = 52) and compared them with two control groups: 46 patients aged 71-84 and 32 patients <70, treated with cemiplimab for cSCC. Demographics, treatment characteristics, outcomes and toxicity were evaluated. Inverse probability of treatment weighting (IPTW) was applied when comparing survival outcomes.

Although patients >85 had worse ECOG scores and less inclined to undergo surgery, no significant differences were noted in the overall response rates (68.8% and 76.1% for <70 and 71-84, respectively vs. 73.1% for >85, P = .744) or disease control rates (75% and 82.6% for <70 and 71-84, respectively vs. 75% for >85, P = .627). After IPTW adjustment, progression-free survival (PFS) did not differ between groups (HR = 1.08, 95% CI 0.55-2.13, P = .82). Cancer specific survival (CSS) also did not differ between groups (HR = 1.05, 95% CI 0.22-4.87, P = .955). However, overall survival (OS) was shorter among patients >85 (HR = 2.64, 95% CI 1.43-4.86, P = .002). Toxicity profiles were similar, although toxicity-related deaths occurred more frequently in the >85 cohort.

Cemiplimab showed comparable efficacy and tolerability across age groups, with no significant difference in PFS and CSS, but shorter OS among very elderly patients with cSCC, reflecting competing non-cancer mortality rather than reduced treatment efficacy.