Pembrolizumab in Treating Patients With High Risk Oral Intraepithelial Neoplasia

PRIMARY OBJECTIVE: I. To determine oral cancer-free survival of patients with high risk oral intra-epithelial neoplasias (IEN) treated with pembrolizumab versus observation. SECONDARY OBJECTIVES: I. To determine the safety and tolerability of pembrolizumab for patients with oral IEN. OUTLINE: Patients are randomized to 1 of 2 arms. ARM A: Patients undergo observation. ARM B: Patients receive pembrolizumab intravenously (IV) over 30 minutes on day 1. Treatment repeats every 21 days for up to 4 courses in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up at 6, 9, 12, 18, 24, 30, and 36 months and then periodically thereafter.