Repros drops top dose for late-stage study

Repros Therapeutics is recalibrating clinical studies of its lead drug, dropping a 50 mg dose after researchers found that a small percentage of women in the studies of Proellex as a treatment for endometriosis demonstrated a dose-dependent increase in liver enzymes, a key marker of toxicity.

But Repros also noted that there was no difference in efficacy between patients taking a 25 mg dose and another group given a 50 mg dose in a clinical trial. Late-stage studies of a 12.5 mg dose and 25 mg dose are scheduled to launch later this year and in the first quarter of 2010 in Europe and the United States.

Repros shares were dinged by the news, sliding five percent. The developer says it will sit down with the FDA in September to review plans for a late-stage trial. It is also planning additional placebo-controlled studies of the 12.5 mg dose. But Repros adds that it does not expect that the new trial plans will delay a planned NDA in the second half of next year.

- check out the Repros release
- read the story from Reuters