Immunotherapy in Patients With Metastatic Cancers and CDK12 Mutations

Inclusion Criteria: * Be ≥18 years of age as of date of signing informed consent. * Be willing and able to provide written informed consent for the study. * ECOG Performance Status of 0, 1 or 2 (Eastern Cooperative Oncology Group scoring system used to quantify general well-being and activities of daily life; scores range from 0 to 5 where 0 represents perfect health and 5 represents death. * Subjects must have a histologic or cytologic diagnosis of metastatic adenocarcinoma of the prostate without small cell histology OR another type of metastatic carcinoma. * All subjects, regardless of cancer type, must have a documented CDK12 aberration in tumor tissue. * Subjects with prostate cancer must have documented prostate cancer progression within six months prior to screening with PSA progression defined as a minimum of three rising PSA levels ≥ 1; 1 week between each assessment with a baseline PSA value at screening of ≥ 2 ng/mL. * Subjects with prostate cancer must have ongoing androgen deprivation with total serum testosterone \< 50 ng/dL (or ≤ 0.50 ng/mL or 1.73 nmol/L)). If the subject is currently being treated with LHRH agonists (subjects who have not undergone an orchiectomy), this therapy must have been initiated at least 4 weeks prior to registration. This treatment must be continued throughout the study. * Subjects with non-prostate histologies must have RECIST 1.1-measurable cancer on computed tomography (CT) or magnetic resonance imaging (MRI) scans. * Subjects must have recovered to baseline or ≤ grade 1 toxicities related to any prior treatments unless AE(s) are clinically non-significant and/or stable. * Patients must be ≥ 2 weeks from most recent systemic therapy or most recent radiation therapy. * Women of childbearing potential must have a negative serum or urine pregnancy test within 28 days prior to registration. * Female and male subjects of reproductive potential must agree to use an adequate method of contraception starting with the first dose of study therapy through 5 months (for women) and 7 months (for men) after the last dose of study therapy. * Adequate organ and marrow function Exclusion Criteria: * Prior treatment with anti-PD-1/PD-L1 and anti-CTLA-4 is NOT allowed. Prior intravesical BCG therapy is allowed. * Treatment with any investigational agent or on an interventional clinical trial within 28 days prior to registration. * Prior or concurrent malignancy except for: adequately treated basal cell or squamous cell skin cancer, in situ cervical cancer, localized or locally advanced prostate cancer definitively treated without recurrence or with biochemical recurrence only, or any other cancer fully treated or from which the subject has been disease-free for at least 2 years. * Autoimmune diseases such as rheumatoid arthritis. Vitiligo, mild psoriasis (topical therapy only) or hypothyroidism are allowed. * Need for systemic corticosteroids \>10mg prednisone daily or equivalent alternative steroid (except physiologic dose for adrenal replacement therapy) or other immunosuppressive agents (such as cyclosporine or methotrexate) Topical and inhaled corticosteroids are allowed if medically needed. * Any history of organ allografts * Any history of HIV, hepatitis B or hepatitis C infection