Prospective Phase II Trial of Definitive Chemoradiation and Concurrent Nivolumab in Locally Advanced p16+ Oropharynx Cancer. (2025)

[PURPOSE] We conducted a prospective, single-institution phase II trial to test the hypothesis that the addition of nivolumab to definitive chemoradiation would improve the progression-free survival (PFS) among patients with high-risk p16+ oropharyngeal squamous cell carcinoma (OPSCC).

[METHODS AND MATERIALS] Patients with previously-untreated locoregionally advanced, p16+ OPSCC (clinical T4/N3, matted lymph nodes, and/or retropharyngeal lymphadenopathy) were enrolled. Patients received a priming dose of nivolumab, concurrent nivolumab and chemoradiation (70 Gy to PTVhigh, 56 Gy to PTVlow, weekly carboplatin/paclitaxel), and 4 cycles of adjuvant nivolumab over 12 weeks. The primary endpoint was 2-year PFS compared to an institutional historic control of 68%. Exploratory endpoints included