Phenelzine Sulfate in Treating Patients With Non-metastatic Recurrent Prostate Cancer

Inclusion Criteria:

Histologically confirmed adenocarcinoma of the prostate

Recurrent prostate cancer following primary therapy as defined by:

Post-radical prostatectomy: Any PSA >= 0.4 ng/ml
Post-primary radiotherapy: PSA >= 2 ng/ml above a post-radiotherapy nadir
Post-primary androgen-deprivation therapy: A confirmed rise of PSA >= 2 ng/ml above a post-therapy nadir

For patients with non-castrate levels of circulating androgen levels (testosterone >= 50 g/dl)

PSA levels should be increasing on at least two occasions >= 1 week apart
Patients should not be considered candidates for radiation therapy

For patients with castrate levels of circulating androgen levels (testosterone < 50 ng/dl):

PSA levels must be >= 0.4 ng/ml (if history of radical prostatectomy) or >= 2 ng/ml (if history of non-surgical primary treatment) and found to be increasing on at least two occasions >= 1 week apart
At least 4 weeks must have elapsed since any changes to hormonal therapy, including at least 4 weeks since flutamide and at least 6 weeks since bicalutamide, nilutamide, or enzalutamide
No evidence of metastatic cancer on imaging including a bone scan and computed tomography (CT) scan of chest/abdomen/pelvis
Able to understand and adhere to dietary and medication restrictions as recommended for the safe use of phenelzine
Men with child bearing potential are required to use an effective means of contraception
Leukocytes >= 3,000/mcL
Absolute neutrophil count >= 1,500/mcL
Platelets >= 100,000/mcL
Total bilirubin =< 1.5 x upper limit of normal (ULN) except in cases of benign isolated hyperbilirubinemia such as Gilbert's syndrome.
Aspartate aminotransferase (AST) (serum glutamic oxaloacetic transaminase [SGOT])/alanine aminotransferase (ALT) (serum glutamate pyruvate transaminase [SPGT]) =< 2.5 x ULN
Creatinine =< 1.5 x ULN

Exclusion Criteria:

Uncontrolled hypertension despite appropriate medical therapy (blood pressure [BP] greater than 160 mmHg systolic and 90 mmHg diastolic at 2 separate measurements no more than 60 minutes apart during the screening visit); Note: patients may be rescreened after adjustment of antihypertensive medications
Known prior history of mania or major psychiatric illness (schizophrenia, bipolar disorder, severe major depression requiring hospitalization, etc.)
Concurrent use of medications contra-indicated due to potential interactions with phenelzine
Inability to comply with dietary restrictions for foods, supplements, and medications with potential for adverse interactions with phenelzine or to otherwise cooperate fully with the investigator and study personnel
History of allergic reactions attributed to compounds of similar chemical or biologic composition to phenelzine or other monoamine oxidase inhibitors
Patients may not be receiving any other investigational agents
Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements