-  INCLUSION CRITERIA:

        Participants must have histologically or cytologically confirmed any solid tumor (Cohort 1)
        or castration-resistant prostate cancer (CRPC, Cohorts 2A, 2D and 2R). No prior treatment
        other than testosterone lowering therapy for CRPC is required.

        For the Cohort 1, eligible participants must have a histologically, cytologically or
        radiographically proven metastatic or locally advanced solid tumor of any type, for which
        there is no curative standard therapy or standard therapy has failed.

        Castrate testosterone level (less than 50ng/dl or 1.7nmol /L). (Participants with a
        malignancy other than prostate cancer are excluded from this criterion).

        Radiological confirmation of metastatic disease, or

        Progressive disease at study entry defined as one or more of the following criteria
        occurring in the setting of castrate levels of testosterone:

        --Radiographic progression defined as any new or enlarging bone lesions or growing lymph
        node disease, consistent with prostate cancer

        OR

        --PSA progression defined by sequence of rising values separated by greater than 1 week (2
        separate increasing values over a minimum of 1 ng/ml (PCWG3 PSA eligibility criteria). If
        participants had been on flutamide, PSA progression is documented 4 weeks or more after
        withdrawal. For participants on bicalutamide or nilutamide disease progression is
        documented 6 or more weeks after withdrawal. The requirement for a 4-6 week withdrawal
        period following discontinuation of flutamide, nilutamide or bicalutamide only applies to
        participants who have been on these drugs for at least the prior 6 months. For all other
        participants they must stop bicalutamide, nilutamide or flutamide the day prior to
        enrollment.

        Asymptomatic or mildly symptomatic form prostate cancer; no use of regularly scheduled
        opiate analgesics for prostate cancer-related pain. (Participants with a malignancy other
        than prostate cancer are excluded from this criterion).

        Participants must agree to continuation of androgen deprivation therapy (ADT) with a
        gonadotropin-releasing hormone analogue/antagonist or bilateral orchiectomy.

        (Participants with a malignancy other than prostate cancer are excluded from this
        criterion).

        Age greater than or equal to 18 years.

        ECOG performance status less than or equal to 1

        Participants must have adequate organ and marrow function as defined below:

          -  Absolute neutrophil count greater than or equal to 1000/mcL

          -  Platelets greater than or equal to 100,000/mcL

          -  Hemoglobin greater than or equal to 9.0 g/dL

          -  Total bilirubin within normal institutional limits; in participants with Gilbert s,
             less than or equal to 3.0 mg/dL

          -  AST (AGOT)/ALT (AGPT) less than or equal to 2.5X upper limit of normal. For subjects
             with liver involvement in their tumor, AST less than or equal to 3.5. (SqrRoot) ULN,
             ALT less than or equal to 3.5 (SqrRoot) ULN, and bilirubin less than or equal to 3.0
             is acceptable

          -  Creatinine within 1.5X upper limit of normal institutional limits

        The effects of BN-Brachyury, M7824, N-803, and Epacadostat on the developing human fetus
        are unknown. For this reason, men and women must agree to use adequate contraception
        (hormonal or barrier method of birth control; abstinence) prior to study entry, during the
        study and maintain such contraception until 4 months following the last dose of any study
        agent. Should a woman become pregnant or suspect she is pregnant while she or her partner
        is participating in this study, she should inform her partner s treating physician
        immediately.

        Ability of subject to understand and the willingness to sign a written informed consent
        document.

        Participants with successfully treated HCV are eligible if HCV viral load is undetectable.

        EXCLUSION CRITERIA:

        Participants who are immunocompromised as follows:

          -  Human immunodeficiency virus positivity due to the potential for decreased tolerance,
             and potential to be at risk for severe side effects with immunotherapies. These
             concerns are relevant to all drugs, as drug-drug interactions among antiretrovirals
             and immunotherapies are yet uncharacterized.

          -  Chronic administration (defined as daily or every other day for continued use greater
             than 14 days) of systemic corticosteroids or other immune suppressive drugs, within 28
             days before treatment on study. Nasal, or inhaled steroid, topical steroid creams and
             eye drops for small body areas are allowed.

          -  Participants who have undergone allogeneic peripheral stem cell transplantation, or
             solid organ transplantation requiring immunosuppression

               -  Active autoimmune disease, except participants with type 1 diabetes mellitus,
                  vitiligo, psoriasis, hypo- or hyperthyroid disease not requiring current
                  immunosuppression, or with other endocrine disorders on replacement hormones or
                  are not excluded if the condition is well controlled.

        Prostate cancer participants with a history of brain/leptomeningeal metastasis, since these
        participants have a very poor prognosis and immunotherapy may take time to lead to
        beneficial clinical effects. Participants with brain or CNS metastases enrolling to arm 1.1
        are eligible if they are status post definitive radiotherapy or surgery, and are
        asymptomatic

        History of allergic reactions attributed to compounds of similar chemical or biologic
        composition to study agents to be used in the cohort the subject will be enrolled into.

        Known allergy to eggs, egg products, aminoglycoside antibiotics (for example, gentamicin or
        tobramycin).

        Any condition which, in the opinion of the investigator, would prevent full participation
        in this trial (including the long-term follow-up), or would interfere with the evaluation
        of the trial endpoints.

        Participants with prior investigational drug, chemotherapy, immunotherapy or any prior
        radiotherapy (except for palliative bone directed therapy) within the past 28 days prior to
        enrollment, except if the investigator has assessed that all residual treatment-related
        toxicities have resolved or are minimal and feel the participant is otherwise suitable for
        enrollment.

        Uncontrolled intercurrent acute or chronic illness including, but not limited to, ongoing
        or active infection, symptomatic congestive heart failure (>New York Heart Association
        Class I), hepatic disease, unstable angina pectoris, serious cardiac arrhythmia, requiring
        medication, uncontrolled hypertension (SBP>170/ DBP>105) or psychiatric illness/social
        situations within 12 months that would limit compliance with study requirements.

        Use of herbal products that may decrease PSA levels (e.g. saw palmetto)

        Participants who have had cytotoxic chemotherapy for metastatic castration-resistant
        prostate cancer within the past year. (Participants who have had docetaxel for metastatic
        castration sensitive per CHAARTED data may enroll as long as they did not have progressive
        disease while on docetaxel and are 3 months removed from treatment, with all treatment
        related toxicities resolving to at least grade 1.)

        Participants who have undergone major surgery within 4 weeks of enrollment. A biopsy will
        not preclude a participant from starting study.

        Participants with a history of hepatitis B (HBV) are excluded due to potential risk for
        viral reactivation and resulting liver injury in persons with latent HBV

        For participants enrolling in Arm 2.3A and for participants who may be randomized to Arm
        2.3B, the following additional exclusion criteria will apply:

          -  Subjects receiving Monoamine Oxidase Inhibitors (MAOIs) or a drug which has
             significant MAOI activity (meperidine, linezolid, methylene blue) within the 21 days
             before initiation of study therapy are excluded.

          -  Since epacadostat s metabolism may be altered by drugs that inhibit UDP-
             glucuronosyltransferase UGT1A9 (see Appendix D), Participants receiving such drugs
             within 21 days of initiation of study therapy are excluded.

          -  Participants receiving agents that are substrates of CYP1A2, CYP2C8, and CYP2C19 or
             affected by OATP1B1 or OATP1B3 within 21 days of initiation of study therapy or 5 half
             lives of the agent (whichever is shorter) are excluded. Participants receiving
             medications that are substrates of these enzymes/transporters but are not listed in
             the appendix or participants receiving substrates of CYP2B6 and CYP3A will be
             evaluated on a case-by-case basis prior to enrollment. Participants who consume
             caffeine are eligible but must agree to moderate consumption.

          -  Subjects receiving coumarin-based anticoagulants (e. Coumadin) are excluded.

          -  Subjects having any history of Serotonin Syndrome (SS) after receiving serotonergic
             drugs are excluded.

             --Participants with a QTcF interval > 480 milliseconds at the screening are excluded.
             In the event that a single QTcF is > 480 milliseconds, the subject may enroll if the
             average QTcF for the 3 ECGs is < 480 milliseconds. For subjects with an
             intraventricular conduction delay (QRS interval > 120 milliseconds), the JTc interval
             may be used in place of the QTc. The JTc must be < 340 milliseconds if JTc is used in
             place of the QTc. QTc prolongation due to pacemaker may enroll if the JTc is normal.

          -  Subjects with left bundle branch block are excluded.

          -  Pregnant women are excluded from this study because investigational agents used in
             this study (BN-Brachyury, M7824, N-803, and/or Epacadostat) could have teratogenic or
             abortifacient effects. Because there is an unknown but potential risk for adverse
             events in nursing infants secondary to treatment of the mother with these
             investigational agen s, breastfeeding should be discontinued if the mother is treated
             with either of them.