Background: Treatment options for patients (pts) with R/M NPC are limited to palliative chemotherapy. NPC is often associated with the Epstein–Barr virus (EBV), a potential antigen for immune recognition, and high expression levels of the immune checkpoint receptor programmed death-1 (PD-1) and its major ligand PD-L1. Nivolumab disrupts PD-1–mediated signaling, restoring T-cell antitumor function. Methods: In CheckMate 358 (NCT02488759), PD-L1–unselected adults with R/M NPC, ECOG PS of 0–1, and ≤2 prior systemic therapies in the R/M setting were eligible to receive nivolumab 240 mg every 2 weeks until progression or unacceptable toxicity, as part of an ongoing multicohort study of 5 virus-associated cancers. Human papillomavirus-associated NPC and keratinizing squamous cell carcinoma (WHO Type 1) were excluded. Primary endpoints were objective response rate (ORR) and safety; secondary endpoints were duration of response (DoR), progression-free survival (PFS), and overall survival (OS). Results: Of 24 treated pts with R/M NPC, median age was 51 years, 88% were male, 62% were white, 88% were European, and 88% had EBV+ tumors. At a median follow-up of 26 weeks (range: 4–40), ORR was 20.8% and appeared to be higher in pts with no prior R/M therapy (Table). The disease control rate (ORR + SD) was 45.8%. Responses were observed regardless of PD-L1 or EBV status. Median PFS was 2.4 mo (95% CI: 1.5, NR); median OS was NR. Conclusions: Nivolumab demonstrated clinical activity and a manageable safety profile in R/M NPC, supporting ongoing research with nivolumab in this disease. Updated efficacy and biomarker data will be presented. Clinical trial information: NCT02488759

NR = not reached.