A Study of Cemiplimab and Fianlimab in People With Nasopharyngeal Carcinoma

The purpose of this study is to find out whether cemiplimab, with or without fianlimab, is an effective treatment for advanced nasopharyngeal carcinoma (NPC), when given with standard chemotherapy drugs gemcitabine and cisplatin before standard chemoradiation.

Inclusion Criteria: * Age ≥ 18 * Pathologically (histologically or cytologically) proven (from primary lesion and/or lymph node) diagnosis of non-keratinizing nasopharynx carcinoma * Pathologic confirmation of EBV status in biopsy sample. EBER (Epstein-Barr virus-encoded RNA) detection via immunohistochemistry or in situ hybridization or polymerase chain reaction, collected as routine clinical standard to determine EBV status. * Patient must be seen by head and neck surgery, radiation oncology, medical oncology, as standard of care which includes standard nasopharyngoscopy. All three disciplines need to agree that the patient is eligible. Note: Nasopharyngoscopy does not need to be repeated by all three disciplines. This test is often only performed by head and neck surgery and/or radiation oncology. * AJCC 8th edition: T1N1, T2N0-1, T1-T2N2 nasopharynx carcinoma * ECOG performance status 0-1 * Adequate organ and bone marrow function documented by: * Hemoglobin \> 9.0 g/dL * Absolute neutrophil count (ANC) \>1.5 x 109 /L * Platelet count \>100 x 109 /L * Adequate renal function: Serum creatinine \