5-Azacytidine and/or Nivolumab in Resectable HPV-Associated HNSCC

This study is being done because both 5-azacytidine and nivolumab can influence the immune system's response to HPV-associated head and neck cancer, and we wish to evaluate whether taking 5-azacytidine will make HPV-associated head and neck cancer more sensitive to treatment with nivolumab. 5-Azacytidine (5-AZA) is a chemotherapy, and nivolumab is an immunotherapy. Both drugs are approved for use in the US by the Food and Drug Administration (FDA) for use in the treatment of different types of cancer, and nivolumab is approved for use in head and neck cancer that has previously been treated with chemotherapy. Because they are not approved to be used together in HPV-associated head and neck cancer, these drugs are considered experimental in this study. For this study, the drugs will be used either together or separately.