This study is being done to answer the following question:
Does maintenance nivolumab following definitive therapy with radiation and chemotherapy (cisplatin) result in significant improvement in overall survival (OS) (time being alive) for patients with your type of cancer (intermediate risk HPV positive oropharynx cancer).
We are doing this study because we want to find out if this approach is better or worse than the usual approach for your HPV positive oropharynx cancer. The usual approach is defined as care most people get for HPV positive oropharynx cancer.
- ECOG performance status of 0 or 1.
- Patients must have tumor measurements with CT of neck and CT of chest (or CT of neck and FDG PET/CT if standard of care) within 4 weeks prior to Step 1 randomization)
- Patients must not have known hypersensitivity to nivolumab or compounds of similar chemical or biologic composition.
- Participants with a history of allergic reactions attributed to platinum-based chemotherapy agents are excluded.
- Participants must not have received previous irradiation for head and neck tumor, skull base, or brain tumors.
Participants will get chemotherapy weekly for up to 7 weeks and radiation daily excluding weekends, for up to 7 weeks. Then they will either get nivolumab for up to 12 months and be monitored and observed, or they will be monitored and observed without getting nivolumab. If the cancer grows during observation, participants will then be offered nivolumab for up to 12 months.
After treatment, the doctor and study team will watch participants for side effects. They will check on participants every 3-6 months for 3 years after treatment. After that, they may check participants every year.