Androxal enclomiphene: Completed Phase III enrollment

Repros completed enrollment of 500 patients in the 6-month, open-label, dose-escalation, U.S. Phase III ZA-300 trial comparing once-daily, oral 12.5 mg Androxal vs. topical Axiron testosterone. The company said the trial is part of FDA's requirement for the total number of patients to be exposed to Androxal for 6 months. The company is also evaluating Androxal in a pair of identical 12-week, double-blind, U.S. Phase III trials - ZA-301 and ZA-302.

Additionally, Repros said it submitted a "request for guidance" to FDA related to the identification of a patient population from 1 trial site in ZA-301 that was "markedly different" from the other 16 sites. The company proposed enrolling an additional 40 patients in each of the ZA-301 and ZA-302 trials to allow for subset analyses while retaining the statistical power of the original protocols and proposed moving 2 sites in ZA-302 to ZA-301. Under the trials' SPA, the trials would demonstrate sperm concentration efficacy, an FDA-required endpoint, if >=75% of patients in the Androxal group achieved mean sperm concentrations in the normal range of 300 ng/dL-1,040 ng/dL, with the lower bound of the 95% CI not below 67%. ZA-302 was expected to complete enrollment in May, while ZA-301 has already completed enrollment of 151 patients. Data from ZA-301 are still expected in 3Q13. Repros, which has an SPA from FDA for both trials, said an NDA submission is planned for June 2014 (see BioCentury, Feb. 4). ...