Shares of Repros Therapeutics (RPRX) are cruising higher in Thursday trading following the Woodland, Texas-based drug maker reporting on Wednesday that top-line results from the first phase 3 clinical trial of Androxal, ZA-301, an oral therapy for hypogonadism hit both its primary endpoints. Hypogonadism is a condition in which the testes don’t produce enough testosterone. Androxal works by blocking estrogen production, allowing the body to produce more testosterone.
The clinical trial included 151 patients, consisting of 38 on placebo and 113 receiving Androxal.
Repros said that initial results showed its drug candidate helped restore testosterone levels into a normal range in 79 percent of the Intent-to-Treat patients. This meets requirements of the Food and Drug Administration stipulating that 75 percent of the subjects in the drug arm exhibit a 24-hour average total testosterone in the normal range (300–1040 ng/dL) at the end of 12 weeks of treatment.
The results included some “carry-through” data of a handful of patients that didn’t complete the trial. A more complete analysis showed 83 percent of the men that completed the study were in the normal range. Only six men dropped-out of the study, but none cited adverse effects as the reason for discontinuation.
Throughout the study, Androxal was shown to be well tolerated, with no serious adverse events reported.
The FDA also stipulated required results on sperm concentration compared to the placebo as a co-primary endpoint, which Androxal met by demonstrating that the drug maintains or increases sperm count.
“We are obviously pleased with these results. As we expect full enrollment in the sister pivotal study ZA-302 by the end of May, today’s outcome encourages us that a similar outcome will be realized,” said Joseph S. Podolski, president and chief executive at Repros.
Shares of RPRX have been volatile in recent trading as biotech traders are keenly aware of the potential revenue of an oral drug for low testosterone compared to FDA-approved gel treatment should Androxal make it to market.
Repros stock had been steadily climbing leading into the pivotal trials, rising as high as $19.12 per share before reports that results could be delayed until the second half of the year sent the stock plummeting in January to lows of $8.42 last week.
The meeting of the primary endpoints has shares galloping ahead on Thursday, launching more than 70 percent to as high as $16.15 by midday trading.