Repros Therapeutics Inc. ® (NasdaqCM:RPRX) today reported it has received Institutional Review Board (IRB) approval to commence the Phase IIb study of Androxal ® in men with secondary hypogonadism. The Company has submitted the protocol for FDA comment and plans to begin enrolling subjects in January. Depending on the rate of subject enrollment, Repros hopes to have the study completed before the end of 2011.
The study will be conducted at up to 20 US clinical sites. Two sites in Texas have been initiated already and have commenced screening subjects. At this time the Company is planning to have sites in Houston and San Antonio, Texas; the metropolitan area of New York City; and San Diego, Los Angeles and Sacramento, California. The Company is also considering sites in Las Vegas, Nevada.
The study will enroll up to 120 men with morning testosterone levels < 250 ng/dl. The men must be naïve to testosterone therapy or have not used testosterone for at least six months. The men will be equally randomized to four different groups, double blind Androxal 12.5 mg and 25 mg, matching placebo and open label Testim used per manufacturer’s recommendations. Men will be dosed for three months.
The primary efficacy endpoint of the study is change in morning testosterone levels comparing the baseline visit to the levels achieved after three months to those achieved for placebo. Changes in pituitary hormones that control testicular function will be assessed as secondary efficacy measures.Change in reproductive status as determined by semen analyses will be a safety endpoint as instructed by the FDA. Analyses of previously completed studies by independent statisticians suggest that this study is well powered to achieve statistical significance for the primary and secondary efficacy endpoints. Those completed studies comparing Androxal to topical testosterone preparations showed statistically significant suppression of pituitary hormones that regulate testicular function by the replacement therapies. These findings suggest that the topical preparations will be viewed negatively when assessed from the perspective of reproductive status.