Patient description: The patient is a 63-year-old man presenting to the Emergency Department with a history of acute urinary retention in the past 2 days. Abdominopelvic CT scan revealed a large prostate and a bladder filled with urine. He is a candidate for urethral catheterization and TURP. Further evaluation revealed: Post-void residual: 71 mL Prostate volume (TRUS): 63 mL Prostate-specific antigen (PSA) level: 3.5 ng/mL His recent blood chemistry (3 days ago) was normal: Hgb: 13.6 g/dl WBC: 133000 /mm3 Plt: 370000 /ml PT: 12 second PTT: 34 second INR: 0.9 Creatinine: 0.5 mg/dl BUN: 10 mg/dl U/A: Color: yellow Appearance: cloudy PH: 5.3 Specific gravity: 1.010 Glc: 100 Nitrite: negative Ketone: none Leukocyte esterase: negative RBC: negative WBC: 2 WBCs/hpf U/C: negative

Clinical trial eligibility criteria: eligible ages (years): 18.0-999.0,  Metastatic Prostate Cancer Written informed consent and Health Insurance Portability and Accountability Act (HIPAA) authorization for release of personal health information. NOTE: HIPAA authorization may be included in the informed consent or obtained separately Age ≥ 18 years at the time of consent Eastern Cooperative Oncology Group (ECOG) Performance Status of 0-1 within 14 days prior to registration Men who are not surgically sterile (vasectomy) must agree to use an acceptable method of contraception. Male subjects with female sexual partners who are pregnant, possibly pregnant, or who could become pregnant during the study must agree to use condoms from the first dose of study drug through at least 120 days after the last dose of study drug. Total abstinence for the same study period is an acceptable alternative Documented histologically or cytologically confirmed adenocarcinoma of the prostate Ongoing androgen deprivation therapy with a Gonadotropin Releasing Hormone (GnRH) analogue or bilateral orchiectomy. Subjects who have not undergone orchiectomy must plan to continue GnRH analogue therapy for the duration of the trial All subjects on oral anti-androgen therapy must have been off therapy for at least 4 weeks prior to registration (6 weeks for bicalutamide) to an anti-androgen withdrawal response. Patients who received secondary anti-androgen therapy and did not exhibit a >50% PSA decline, or subjects with any rise in PSA, objective or symptomatic progression following anti-androgen withdrawal will not be required to meet this withdrawal requirement Documented metastatic disease with prostate-specific antigen (PSA) progression, radiographic progression, or both, despite receiving luteinizing hormone releasing hormone (LHRH) analogue therapy or orchiectomy with a serum testosterone level of 50 ng/dL or less PSA progression is defined as three successive rising PSA values with an interval of at least one week between determinations Radiographic progression is defined by Response Evaluation in Solid Tumors (RECIST) 1.1 or at least two new lesions on bone scan  Prior enzalutamide or other next-generation androgen receptor (AR) targeting therapy Prior PARP-inhibitor therapy History of or active central nervous system (CNS) metastases. Subjects with neurological symptoms must undergo a head computed tomography (CT) scan or brain magnetic resonance imaging (MRI) to brain metastasis Radioisotope or external beam radiation exposure in the last 4 weeks. Exposure to strontium, regardless of when exposure occurred Prior radiation to 25% or more of the bone marrow Treatment with any investigational agent within 28 days prior to registration Known significant immunodeficiency as determined by the site investigator Prior malignancy except for adequately treated basal cell or squamous cell skin cancer, or other cancer for which the subject has been disease-free or stable for at least one year Prolonged QTc over 470 ms