Shares of thinly-traded Repros Therapeutics (NASDAQ:RPRX) are up 14% premarket on healthy volume in response to its report of successful results in a Phase 3 clinical trial comparing its secondary hypogonadism treatment Androxal (single isomer of clomiphene citrate) to Abbvie's (NYSE:ABBV) Androgel (testosterone gel) and placebo.
In the study, called ZA-305, Androxal demonstrated superiority in the two co-primary endpoints of percent change from baseline in average sperm concentration and percent of subjects considered to be responders.
23.8% of topical testosterone (Topical T) subjects were below 10M sperm/mL at the end of the study compared to 2.3% for Androxal and 2.4% for placebo. Baseline sperm concentration increased 5.9% for Androxal versus a reduction of 33.3% from baseline for the Topical T group. Androxal responder rate was 65.9% compared to 33.3% for Topical T.
Mean change in sperm concentration from baseline was +14% for Androxal, -30% for Androgel and +7% for placebo.