Real-world Therapeutic Outcomes of the Pembrolizumab Regimen as First-line Therapy for Recurrent/Metastatic Squamous Cell Carcinoma of the Head and Neck: A Single-center Retrospective Cohort Study in Japan

Abstract

Background/aim: This Japanese single-center retrospective cohort study aimed to evaluate the real-world therapeutic outcomes of pembrolizumab or pembrolizumab plus chemotherapy (pembrolizumab regimen) as first-line therapy for patients with recurrent/metastatic squamous cell carcinoma of the head and neck (R/M SCCHN).

Patients and methods: Thirty-two Japanese patients with R/M SCCHN treated with the pembrolizumab regimen between January 2020 and January 2022 were analyzed. The primary endpoint of the study was overall survival.

Results: The median follow-up duration was 9.8 months (range=1.6-25.1 months). Fourteen patients received pembrolizumab alone, whereas the others received pembrolizumab with chemotherapy. The 1-year overall and progression-free survival rates were 64.5% (95% CI=38.9-81.6) and 54.9% (95% CI=33.9-71.8), respectively. The objective response rate was 56.2%. The Kaplan-Meier analysis showed that patients with favorable objective responses and an Eastern Cooperative Oncology Group performance status of 0 had longer survival. Immune-related adverse events (irAEs) occurred in 16 out of 32 patients (50.0%) during treatment; however, there were no irAEs greater than grade 4.

Conclusion: The observed therapeutic efficacy and safety of pembrolizumab in real-world clinical practice was consistent with the data of the KEYNOTE-048 trial.

Keywords: Recurrent/metastatic squamous cell carcinoma; head and neck; pembrolizumab; programmed cell death protein 1.