Nivolumab + Docetaxel + ADT in mHSPC Patients With DDRD or Inflamed Tumors

This research study is studying a combination of hormonal therapy, chemotherapy, and immunotherapy as a possible treatment for metastatic hormone-sensitive prostate cancer. The names of the study drugs involved in this study are: * Androgen deprivation therapy (ADT) with a drug of your physician's choice. This may include leuprolide (Lupron), goserelin acetate (Zoladex), or degarelix (Firmagon). * Docetaxel * Nivolumab

This research study is a Phase 2 clinical trial. Phase 2 clinical trials test the safety and effectiveness of investigational drug(s) to learn whether the drug(s) work in treating a specific disease. "Investigational" means that the drug(s) are being studied. The U.S. Food and Drug Administration (FDA) has not approved nivolumab for hormone sensitive prostate cancer. However, nivolumab has been approved for other uses, including for advanced melanoma, lung cancer, head and neck cancer, kidney cancer, and bladder cancer. The U.S. FDA has not approved docetaxel as a treatment option for hormone sensitive prostate cancer. However, docetaxel is approved for advanced hormone resistant prostate cancer and other cancers. There is also evidence from a high quality, phase 3 randomized clinical trial supporting the use of docetaxel in metastatic hormone sensitive prostate cancer patients who have a high burden of metastasis. Docetaxel is an off-label indication for hormone sensitive prostate cancer. The U.S. FDA has approved androgen deprivation therapy (ADT) agents, including leuprolide (Lupron), goserelin acetate (Zoladex), or degarelix (Firmagon), as a treatment option for hormone sensitive prostate cancer. The combination of ADT, also called hormonal therapy, with docetaxel chemotherapy and nivolumab immunotherapy is considered investigational. ADT cuts off the supply of testosterone and is the standard of care for hormone sensitive prostate cancer. The addition of docetaxel chemotherapy has been found to prolong life for prostate cancer patients starting hormonal therapy for the first time for metastatic disease, who also have a large volume of cancer. Another anti-cancer treatment modality is called immunotherapy. The immune system can kill cells that are recognized as different or dangerous, such as infected cells and cancer cells. Nivolumab is an antibody (a type of human protein) that work to stimulate the body's immune system to recognize and fight cancer cells. Hormonal therapy and chemotherapy may make cancer cells more recognizable to the immune system, and make cancer cells more susceptible to immunotherapy. The goal of this study is to examine the activity and safety of hormonal therapy combined with docetaxel chemotherapy and nivolumab immunotherapy for hormone sensitive prostate cancer. The study is designed to enrich for patients whose tumors may be more most responsive to this treatment strategy. All patients will receive the same treatment of ADT combined with docetaxel chemotherapy and nivolumab immunotherapy.