Correlation Of Anti-Tumor Adaptive Immunity With Clinical Response In A Phase Ii "Window" Trial Of Neoadjuvant Cetuximab In Patients With Resectable Stage Iii-Iv Head And Neck Squamous Carcinoma (Hnscc).

6060Background: Despite near universal EGFR expression in HNSCC, the anti-EGFR antibody, cetuximab, improves survival in only 15% of patients. Activation of immune cell subsets might contribute to anti-tumor responses. We investigated the association of cetuximab response with FcγR polymorphism, hypothesized to influence the potency of cetuximab-FcγR binding and NK cell-mediated cytotoxicity, and peripheral EGFR-specific T cells, markers of tumor-antigen specific cellular immunity. Methods: We conducted a prospective phase II “window” trial in patients with previously untreated, resectable stage III-IVA HNSCC (n = 40) using cetuximab (400 mg/m2 then 250mg/m2/week) for 3-4 weeks preoperatively, followed by adjuvant chemoradiation with or without cetuximab. Biomarkers in peripheral blood (PBL) and tumor infiltrating lymphocytes (TIL) were correlated with clinical response and acneiform rash. In the brief window setting,, response was measured using changes in pre/post tumor diameter on CT scans as a continu...