Single Cell Analysis of Response to Neoadjuvant Immunotherapy in Head and Neck Squamous Cell Carcinoma

Subjects were treated on clinical trial protocol NCT02296684, a phase 2 multicenter trial involving preoperative (neoadjuvant) and postoperative (adjuvant) administration of pembrolizumab, an anti-programmed cell death protein-1 (anti-PD-1) inhibitor, in addition to standard of care therapy, for patients with surgically resectable locally advanced head and neck squamous cell carcinoma (HNSCC).Tumor biopsies were collected at baseline (pre-treatment) and again after two doses of neoadjuvant pembrolizumab (post-treatment) at the time of definitive surgical resection to examine changes in the tumor immune microenvironment or features that correlate with response.Tumor specimens were dissociated, sorted using CD3+ or CD45+ microbeads as indicated and mixed in a 1:2 ratio of positive to negative cells to capture both immune and malignant/stromal populations, and submitted for single-cell sequencing (10X Genomics) of T cell receptor (TCR) expression and gene expression analysis.