Intensity-Modulated Radiation Therapy & Nivolumab for Recurrent or Second Primary Head & Neck Squamous Cell Cancer

PRIMARY OBJECTIVE: I. To assess the 1-year progression-free survival (PFS) for patients with recurrent or second primary head and neck squamous cancer treated with intensity-modulated radiation therapy (IMRT) re-irradiation with concurrent and adjuvant nivolumab. SECONDARY OBJECTIVES: I. Evaluate the 1-year (yr) overall survival (OS) of patients treated with re-irradiation and nivolumab. II. Evaluate patient quality of life (QOL). III. Evaluate patterns of failure including local, regional and distant failure rates at 1 yr. IV. Identify and estimate the incidence rate of acute and late toxicities associated with combined re-irradiation and concurrent and adjuvant nivolumab. TERTIARY OBJECTIVE: I. To identify potential biomarkers related to clinical benefit to concurrent and adjuvant nivolumab and re-irradiation in patients with recurrent or second primary (RSP) head and neck squamous cell carcinoma (HNSCC). OUTLINE: Patients receive nivolumab intravenously (IV) over 30 minutes on weeks -2, 0, 2, 4, and 6 and undergo IMRT once daily beginning on week 0 for up to 6-6.5 weeks. Beginning week 10, patients receive nivolumab IV over 30 minutes every 4 weeks for up to 10 courses in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up for 2 years from the beginning of radiation therapy.