Inclusion Criteria:

          -  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.

          -  Histologically confirmed prostate cancer.

          -  High volume metastatic disease (defined as the presence of visceral metastases or ≥3
             bone lesions).

          -  ADT for ≤3 months by day 1 of study chemotherapy; Prior episodes of ADT are allowed
             (i.e. ADT used previously in courses of radiation).

          -  Testosterone <50 ng/dL. Patients must continue primary ADT with an LHRH analogue if
             they have not undergone orchiectomy.

          -  ECOG Performance Status 0 or 1 (see Appendix A)

          -  Patient has adequate bone marrow and organ function as defined by the following
             laboratory values:

               -  Absolute neutrophil count ≥ 1.5 × 10^9/L

               -  Platelets ≥ 100 × 10^9/L

               -  Hemoglobin ≥ 9 g/dl

               -  Serum creatinine ≤ 1.5mg/dL or estimated creatinine clearance ≥ 50 ml/min

               -  In the absence of liver metastases, alanine aminotransferase (ALT) and aspartate
                  aminotransferase (AST) <2.5 x ULN. If the patient has liver metastases, ALT and
                  AST <5 x ULN

               -  Total bilirubin < ULN; or total bilirubin ≤3.0 x ULN or direct bilirubin ≤1.5 x
                  ULN in patients with well-documented Gilbert's Syndrome.

          -  Sexually active males must use a condom during intercourse while taking study drugs
             and for 30 days after stopping treatment and should not father a child in this period.
             A condom is required to be used also by vasectomized men in order to prevent delivery
             of the drug via seminal fluid. Fertile males must use a condom with spermicide (double
             barrier method).

          -  Age ≥ 18 years

        Exclusion Criteria:

          -  Prior exposure to any chemotherapy, PARPi, or immunotherapy for prostate cancer.

          -  Prior abiraterone or enzalutamide, unless therapy was for < 2 weeks

          -  Radiation therapy (including palliative radiotherapy to a metastatic lesion) within 14
             days or major surgery (e.g., open abdominal, pelvic, thoracic, orthopedic or
             neurosurgery) within 28 days of the date of the first dose.

          -  Other systemic therapies for prostate cancer within 28 days or 5 half-lives, whichever
             is shorter, prior to day 1 of chemotherapy (with the exception of anti-androgens like
             bicalutamide).

          -  PSA <2.0 ng/mL at diagnosis.

          -  If present, peripheral neuropathy must be ≤ Grade 1

          -  Patients with an active second malignancy that could, in the investigator's opinion,
             potentially interfere with the patient's ability to participate and/or complete this
             trial.

          -  Patients with central nervous system (CNS) involvement unless they meet ALL of the
             following criteria:

               -  At least 4 weeks from prior therapy completion (including radiation and/or
                  surgery) prior to starting the study treatment

               -  Clinically stable CNS tumor at the time of screening.

               -  Baseline screening for CNS metastases is not required unless presence of signs
                  and/or symptoms of involvement

          -  Patients with severe psychiatric illness/social situations that would limit compliance
             with study requirements in the judgment of treating investigator.

          -  Patient has a history of non-compliance to medical regimen or inability to grant
             consent.