A Selective Androgen Receptor Modulator (OPK-88004) in Prostate Cancer Survivors: A Randomized Trial.

BACKGROUND Androgen deficiency is common among prostate cancer survivors, but many guidelines consider history of prostate cancer a contraindication for testosterone replacement. We determined the safety and efficacy of a selective androgen receptor modulator (OPK-88004) in symptomatic, testosterone-deficient men who had undergone radical prostatectomy for low grade, organ-confined prostate cancer. METHODS In this placebo-controlled, randomized, double-blind trial, 114 men, >19 years, who had undergone radical prostatectomy for low grade, organ-localized prostate cancer, undetectable PSA ( 2 years after radical prostatectomy and testosterone deficiency were randomized in stages to placebo or 1, 5 or 15 mg OPK-88004 daily for 12-weeks. Outcomes included PSA recurrence, sexual activity, sexual desire, erectile function, body composition, muscle strength and physical function measures, mood, fatigue and bone markers. RESULTS Participants were on average 67.5-years and had severe sexual dysfunction (mean erectile function and sexual desire domain scores 7.3, and 14.6, respectively). No participant experienced PSA recurrence or erythrocytosis. OPK-88004 was associated with a dose-related increase in whole body (P<0.001) and appendicular (P<0.001) lean mass and a significantly greater decrease in percent body fat (p<0.001) and serum alkaline phosphatase (p<0.001) than placebo. Changes in sexual activity, sexual desire, erectile function, mood, fatigue, physical performance, and bone markers did not differ among groups (p=0.73). CONCLUSIONS Administration of OPK-8804 was safe and not associated with PSA recurrence in androgen-deficient men who had undergone radical prostatectomy for organ-confined prostate cancer. OPK-88004 increased lean body mass and decreased fat mass, but did not improve sexual symptoms or physical performance.