Administration of a Single Dose of Pembrolizumab, Docetaxel, and Cisplatin Leads to Complete Disappearance of a Locally Advanced Hypopharyngeal Squamous Cell Carcinoma: A Case Report.

INTRODUCTION: Immune-checkpoint inhibition has improved the outcomes of patients with a metastatic squamous cell carcinoma in the head and neck. The combination of pembrolizumab, platinum agent, and 5-fluorouracil had been shown to improve the survival of patients with a positive programmed death ligand 1 (PD-L1) test and had become the standard treatment. Patients with a high combined positive score (CPS) of >20 can be treated solely with pembrolizumab. The treatment is usually continued until disease progression. Induction immunotherapy has also shown benefits. CASE PRESENTATION: We present a case of a locally advanced hypopharyngeal squamous cell carcinoma in a 63-year-old Arabic man who was started on pembrolizumab, docetaxel, and cisplatin for the first treatment cycle, but he failed to show up for the subsequent cycles due to the coronavirus disease 2019 pandemic restrictions. He came back after 10 months with complete clinical and radiological response. CONCLUSION: The present report may possibly be the first to report a case of locally advanced squamous cell carcinoma of the hypopharynx that showed complete clinical and radiological response to a single dose of pembrolizumab, docetaxel, and cisplatin.