Testosterone Therapy With or Without Finasteride After Spinal Cord Injury: TRT-SCI Trial

Inclusion Criteria: * Veterans eligible for care within the Veterans Health Administration (VHA) * Diagnosis of motor incomplete SCI (AIS C-D) for \>24-months involving spinal segment lumbar (L)1 or above from trauma, vascular, or orthopedic pathology * Low total testosterone (\<300 nanograms/decilliter \[ng/dL\]) and/or low free testosterone (\<4.6 ng/dL) * Presence of one or more sign of low testosterone, defined as: * decreased energy * motivation * initiative or self-confidence * increased fatigue or tiredness * reduced sexual desire or activity * decreased spontaneous (e.g., morning) erections or erectile dysfunction * loss of body hair or reduced shaving * feeling sad or blue or having a depressed mood or a persistent low-grade depressive disorder (defined as a score of \>3 on the Patient Health Questionnaire \[PHQ\]-2) * hot flashes * fatigue or irritability * poor concentration or memory * mild unexplained (normocytic-normochromic) anemia, defined as hematocrit (HCT) \<40%, hemoglobin \<13.6 grams/deciliter (g/dL), or red blood cell count \<4.5 million/microliter (mcL) * sleep disturbances or increased sleepiness * reduced muscle bulk, strength, or physical function * increased body fat or body mass index * Presence of motor impairment, defined as self-selected walking pace ≤1.0 meters/second (m/s) on a 10-meter walk test (10mWT), with or without gait devices or braces and with or without assistance from another person, or as self-selected walking pace \>1.0 m/s with reliance on a gait device or brace or with highly compensated movement impairment identified by a trained observer * Medically stable condition asymptomatic for bladder infection, major decubiti, cardiopulmonary disease, or other significant condition that will interfere with the study * Documented approval from a physician verifying medical status Exclusion Criteria: * Involvement in another research study that may influence outcomes * Mental state that precludes understanding the protocol * Life expectancy \<12 months * History of or current congenital spinal cord injury (SCI) (e.g., Chiari malformation, myelomeningocele, intraspinal neoplasm, Friedreich's ataxia) or degenerative spinal disorder (e.g., spinocerebellar degeneration) that may complicate procedures * Amyotrophic lateral sclerosis, multiple sclerosis, or other neurologic injury / impairment that may complicate procedures * Current cancer diagnosis * History of prostate or breast cancer * Any diagnosed or treated cancer in the past 24 months, except basal or squamous cell carcinoma of the skin that has been successfully treated * Any major lower-limb fracture in the past 12 months * Unevaluated circulating prostate-specific antigen (PSA) \>4.0 nanograms/milliliter (ng/mL) or \>3.0 ng/mL in men with prostate cancer risk factors, including agent orange exposure, first degree relative with prostate cancer, or African American background * Currently seeking fertility or expected during the study * Diagnosed gynecomastia * Hematocrit (HCT) \>48% * Any major cardiovascular event in the last 6 months, defined as: * an acute myocardial infarction * any cardiac revascularization procedure including stenting * angioplasty or coronary artery bypass grafting * revascularization of the carotid or middle cerebral artery or procedure to treat critical limb ischemia * hospitalization due to unstable angina * transient ischemic attack * stroke * peripheral vascular disease * Any angina that is not controlled on a current medical regimen (Canadian class II, III, or IV) * Poorly compensated congestive heart failure (New York Heart Association \[NYHA\] class III or IV) * Poorly controlled hypertension when on medication (consistent systolic BP ≥160 mmHg or diastolic BP ≥100 mmHg) * Poorly controlled arrhythmia of any type * Severe valvular heart disease * Baseline electrocardiogram findings such as left bundle branch block or marked abnormality that precludes serial screening for occult ischemic events * History of unprovoked deep venous thrombosis, unprovoked pulmonary embolism, history of recurrent deep venous thrombosis or known thrombophilia * Major non-cardiovascular surgery (e.g., major abdominal or thoracic procedure) within 90 days before screening or a major surgery scheduled at the time of screening * Liver enzymes (aspartate aminotransferase \[AST\] or alanine aminotransferase \[ALT\]) \>1.5 times the normal upper limit * Severe or end-stage chronic kidney disease defined as eGFR \<30 milliliters/minute (mL/min) * Diagnosed, but untreated severe obstructive sleep apnea * Use of an agent that alters sex-steroid metabolism in the past 90 days, such as: testosterone therapy (TRT), compounded or over-the-counter androgenic hormone or androgen precursor, 5-alpha reductase (5AR) inhibitors, growth hormone, clomiphene, aromatase inhibitors, anti-estrogen or estrogen treatment, or others * Use of anti-resorptive or bone anabolic drug therapy in the past 180 days * Acute use (\>5 days) of any opioid (e.g., oxycodone, hydrocodone) or systemic glucocorticoids \>7.5 milligrams (mg)/day prednisone equivalent (e.g., hydrocortisone 30 mg, methylprednisolone 6 mg, or dexamethasone 1.2 mg) in the week before screening, except for men who are taking these for a chronic condition and who are anticipated to continue these for the study duration * Known allergy to any TRT component (e.g., cottonseed oil or other) * Any other condition, lab abnormality, therapy, medical or psychiatric condition, or reason that might pose a risk to the participant, make participation not in the person's best interest, confound the study results (e.g., inability to comply with study requirements), make the participant unsuitable to receive a study intervention, or interfere with their ability to participate for the full study duration