Study of Cabozantinib and Nivolumab in Metastatic Castration Resistant Prostate Cancer

Inclusion Criteria: Subjects must meet all of the following applicable inclusion criteria to participate in this study: * Willing and able to provide, or have a legally authorized representative provide, written informed consent and HIPAA authorization for the release of personal health information. A signed informed consent must be obtained before screening procedures are performed. NOTE: HIPAA authorization may be either included in the informed consent or obtained separately. * Males 18 years of age and above. * Histological or cytological proof of prostate adenocarcinoma or mixed adenocarcinoma/neuroendocrine tumors. Pure small cell of the prostate is not allowed. * ECOG status of ≤ 2 * Progressive mCRPC as defined: 1) castrate levels of serum testosterone \< 50 ng/dL AND 2) progressive disease as defined by PSA or radiographic progression. Subjects with measurable and non-measurable disease (i.e., bone only metastases) are allowed. NOTE: ENROLLMENT of subjects with non-measurable disease (i.e., bone only metastases) will be capped at 50% of enrollment target (n=25). * Must have exposure to one prior taxane (or be taxane ineligible or refuse taxane) AND one prior AR-targeting agent (for example, abiraterone, enzalutamide, apalutamide, darolutamide). Receipt of taxane or AR-targeting agent may be in the hormone sensitive or castration resistant setting. Subjects may have received more than 1 prior Androgen receptor signaling inhibitors (ARSI). Subjects may have had prior…