Repros Therapeutics (RPRX) surged in after-hours trading on Wednesday after the company announced positive results from a Phase 2 study evaluating Proellex (telapristone acetate) for the treatment of premenopausal women with pelvic pain associated with endometriosis. The primary endpoint was the change from baseline in pelvic pain as measured by a scale called Biberoglu and Behrman Symptom Score (BBSS) over the treatment period. 70% of the patients treated with Proellex became amenorrheic, which was associated with a substantial reduction in pain and analgesic use. Responses were similar between the two doses of Proellex so the reported results are pooled. The median percent change from baseline in BBSS score related to menstrual pain was a reduction of 85.4% compared to -37.5% for placebo (p=0.0008). Reductions in non-menstrual pain were also observed but they were similar between the treatment groups.