Testing the Effects of Low Dose Apalutamide on Prostate-Specific Antigen (PSA) Levels in Men Scheduled for Removal of the Prostate Gland

Inclusion Criteria

• Histologically confirmed organ-confined adenocarcinoma of the prostate (PCa) suitable for prostatectomy
• Gleason score =< (4+4), however no Gleason pattern 5
• Current serum PSA =< 20 ng/ml
• Age > 18 years
• Karnofsky >= 70%
• Leukocytes >= 3,000/uL
• Absolute neutrophil count >= 1,500/uL
• Platelets >= 100,000/uL
• Total bilirubin =< 1.5 x institutional upper limit of normal (ULN) (note: in subjects with Gilbert's syndrome, if total bilirubin is > 1.5 x ULN, measure direct and indirect bilirubin and if direct bilirubin is =< 1.5 x ULN, subject may be eligible)
• Aspartate aminotransferase (AST) (serum glutamic oxaloacetic transaminase [SGOT])/alanine aminotransferase (ALT) (serum glutamic pyruvic transaminase [SGPT]) < 2.5 x institutional ULN
• Creatinine < 2 x institutional ULN
• Thyroid stimulating hormone (TSH) within the institutional normal range
• Willing to use adequate contraception (barrier method; abstinence; subject has had a vasectomy; or partner is using effective birth control or is postmenopausal) for the duration of study participation
• Ability to understand and the willingness to sign a written informed consent document

Exclusion Criteria

• Prior or ongoing hormonal treatment for prostate cancer including, but not limited to orchiectomy, antiandrogens, abiraterone, ketoconazole, or estrogens, or luteinizing hormone-releasing hormone (LHRH) agonists/antagonists. Men on stable doses of 5-alpha reductase inhibitors (e.g., finasteride, dutasteride) are eligible as long as there is no planned dose change while on study
• Patients who have prostate cancer with distant metastases
• Presence of neuroendocrine differentiation in the prostate biopsies
• Serum testosterone (blood collected between 7-10 AM for men < 45 years of age and prior to 2 PM for men >= 45 years of age) < 200 ng/dL
• Have a history of prior malignancies other than prostate cancer within the past 2 years, excluding non-melanoma skin cancer
• Severe or unstable angina, myocardial infarction, symptomatic congestive heart failure, arterial or venous thromboembolic events (e.g., pulmonary embolism, cerebrovascular accident including transient ischemic attacks), or clinically significant ventricular arrhythmias within 6 months prior to registration
• History of seizure or known condition that may pre-dispose to seizure (including but not limited to prior stroke, transient ischemic attack, loss of consciousness within 1 year prior to registration, brain arteriovenous malformation; or intracranial masses such as schwannomas and meningiomas that are causing edema or mass effect)
• Use of drugs known to lower the seizure threshold, including: atypical antipsychotics (e.g. clozapine, olanzapine, risperidone, ziprasidone), bupropion, lithium, meperidine, pethidine, phenothiazine antipsychotics (e.g. chlorpromazine, mesoridazine, thioridazine), and tricyclic antidepressants (e.g. amitriptyline, desipramine, doxepin, imipramine, maprotiline, mirtazapine)
• Concurrent use of drugs in category X drug interactions with apalutamide
• Participants may not be receiving any other investigational agents
• History of allergic reactions attributed to compounds of similar chemical composition of apalutamide
• Uncontrolled intermittent illnesses or medical conditions which, in the opinion of the treating physician, would make this protocol unreasonably hazardous for the patient. Such illnesses/conditions may include, but are not limited to, hypertension, ongoing or active infection, or psychiatric illness/social situations