Testosterone Therapy in Castration Resistant Prostate Cancer

Inclusion Criteria:

Provision to sign and date the consent form
Male and age > or = 18 years old
Stated willingness to comply with all study procedures and be available for the duration of the study
Histologically or cytologically proven adenocarcinoma of the prostate
Ongoing ADT for prostate cancer with a GnRH analogue/antagonist or bilateral orchiectomy for at least 6 months prior to day 1
Patients on a first generation anti-androgen (e.g. bicalutamide, flutamide, nilutamide) must have at least a 6-week washout prior to randomization and must show continued PSA progression
Serum testosterone level <50ng/dL at the screening visit

Progressive disease at screening as defined by one or more of the following criteria:

PSA progression: minimum of 2 rising values within an interval of >1 week between values. And a value at screening of >1ng/mL
Soft tissue progression on CT or MRI based on RECIST 1.1 criteria or progression of bone disease according to PCWG3 criteria
Patients worst pain in the last 24 hours must rank less than 4 on a 0-10 scale and patients cannot be on daily narcotic medications to treat cancer-related pain. This assessment must occur within the screening window and be documented in the patient's medical record.

Acceptable Clinical laboratory values at Screening Visit which include:

Absolute neutrophil count ≥ 1000/uL; platelet count ≥ 100,000/uL, hemoglobin ≥ 8g/dL
Total bilirubin ≤ 1.5xULN (unless documented Gilbert's); alanine aminotransferase or aspartate aminotransferase ≤ 2.5xULN
Creatinine ≤ 2mg/dL
Hemoglobin ≤ 17.5 g/dL
Evidence of metastatic disease at any time point on axial imaging or bone scan, or previous biopsy. Stage IV pelvic lymph node involvement is acceptable
Must use a condom if having sex with a pregnant woman
A male patient and his female partner who is of childbearing potential must use 2 acceptable methods of birth control (one of which must include a condom as a barrier method of contraception) starting at screening and continuing throughout the study period and for 3 months after final study drug administration
Patients may have received any number of lines of therapy for castration resistant disease

Exclusion Criteria:

Requires urinary catheterization for voiding due to obstruction secondary to prostatic enlargement that is well documented to be due to prostate cancer or benign prostatic hyperplasia
Evidence of disease in sites or extent that, in the opinion of the investigator, would put the patient at risk from therapy with testosterone due to a potential tumor flare (e.g. high-risk bone lesions which may result in fracture or spinal cord compression

Clinically significant cardiovascular disease as evidenced by any of the following:

Myocardial infarction with 6 months of screening
uncontrolled angina within 3 months of screening
NYHA class 3 or 4 congestive heart failure
clinically significant ventricular arrhythmia
Mobitz II/Second degree/or 3rd degree heart block without a pacemaker in place; uncontrolled HTN (systolic >180mmHg or diastolic >105mmHg at screening
Previous exposure to a second-generation anti-androgen i.e enzalutamide or apalutamide
Received investigational agent within 2 weeks of screening
Therapy with antineoplastic systemic chemotherapy or biological therapy within 2 weeks of screening
Radiation therapy within 2 weeks of screening
History of a prior malignancy (excluding an adequately treated basal or squamous cell skin cancer, superficial bladder cancer, or a cancer in situ) within 5 years prior to study enrollment
History of gastrointestinal disorders (medical disorders or extensive surgery) that may interfere with the absorption of the study agent
Known or suspected brain metastasis or active leptomeningeal disease
History of seizure at any time in the past. Also, history of loss of consciousness or transient ischemic attack within 12 months of Day 1 visit
Have any condition that, in the opinion of the investigator, would compromise the well-being of the subject or the study or prevent the subject from meeting or performing study requirements