Immunotherapy With Chemotherapy and Chemoradiation for Advanced Squamous Cancer of Nasal Cavity / Paranasal Sinuses (I-NAPA)

Primary Objective -Increase overall response rate (ORR), following pembrolizumab combined with induction chemotherapy prior to radiation, from historical 60% with induction chemotherapy alone to 80%. Secondary Objective * Improve the following efficacy endpoints relative to historical results with chemotherapy alone: progression free survival (PFS), overall survival (OS), organ \[orbital, maxillary, cranial\] preservation rate (OPR), and locoregional failure (LRF). * To determine safety and tolerability of pembrolizumab combined with induction chemotherapy and chemoradiation in patients with PNS SCC. * Correlate immune phenotype in tumors and blood, including T cell infiltration and PD-L1 status, with treatment outcomes.