A retrospective study evaluating the efficacy of pembrolizumab for metastatic or locally recurrent head and neck cancer: A real-world experience.

Abstract

e18018 Background: Metastatic and locally recurrent head and neck cancer is an unfortunate occurrence and is associated with a historically poor prognosis. The KEYNOTE 048 trial reported an overall response rate (ORR) of 17% in this patient population after treatment with pembrolizumab. The purpose of our study is to evaluate the real-world outcomes in patients with metastatic or recurrent head and neck cancers treated with pembrolizumab or pembrolizumab containing regimens at our NCI designated comprehensive cancer center. Methods: We reviewed the medical records of 39 patients with advanced head and neck cancers treated with pembrolizumab or pembrolizumab containing regimens between 9/1/2017 and 12/31/2021. Patients with a diagnosis of cutaneous squamous cell carcinoma in the head and neck region and nasopharyngeal cancers were excluded. Results: Thirty-seven patients were included in the final analysis with a median age of 67. The median time to last follow-up was 12 months with a median time on therapy of 3.2 months. The most common location was oropharynx (87%), and 59% of the study population had documented CPS scores greater than 1. Approximately 60% of patients had distant metastatic disease at the time of initiation of pembrolizumab including one patient with symptomatic brain metastases prior to initiation of therapy. The most common site of metastatic disease was the lungs (51%). The ORR was 11.7%, while the median OS and median PFS were 10 and 2.9 months, respectively. Three patients experienced a complete response (CR), including one patient with a lasting, durable response of 50.9 months. The six-month and one-year PFS were 100% in those who responded or had stable disease (five patients). Ten patients (27%) required hospitalization due to treatment related adverse effects. Conclusions: The role of pembrolizumab in the setting of advanced head and neck cancer is well-established based on findings from large clinical trials. We report an ORR of 11.7% and median PFS of 2.9 months in patients treated with pembrolizumab containing regimens. Although the findings of our small retrospective study suggest a lower response rate than previously reported, the progression free survival in responders at six and twelve months was 100%. Identification of potential responders to immunotherapy has been an active area of research and our study suggests that a subset of patients with metastatic and/or locally recurrent head and neck cancer may experience long and durable responses to pembrolizumab containing regimens. [Table: see text]