THE WOODLANDS, Texas, March 16, 2011 (GLOBE NEWSWIRE) -- Repros Therapeutics Inc. ® (Nasdaq:RPRX)today announced it has commenced dosing the 6 mg cohort in the Company's low dose study of Proellex ® following a safety review of data from women that have completed 8 weeks of treatment at a 3 mg dose. No signals of liver toxicity were detected to date in the 3 mg group. Increased levels of drug activity were detected in this second cohort. The Company previously noted that it has observed signals of clinically relevant activity at even the lowest dose, 1 mg. Proellex is an oral therapy in development for the treatment of uterine fibroids and endometriosis. Large Phase III clinical studies exhibited severe liver toxicity in a small percentage of subjects that were exposed to a 50 mg dose. As a result of these observations, the program was placed on full clinical hold until the phenomenon could be better understood. After an analysis of all the subjects that had been exposed to Proellex, Repros petitioned the FDA to allow the Company to conduct a low dose trial to assess impact on the liver and signals of efficacy. In the summer of 2010 the FDA moved Proellex to partial hold status to allow for the low dose study. The trial is enrolling up to 12 subjects per cohort. There are five cohorts; 1, 3, 6, 9 and 12 mg administered per day over the dosing period. The next higher dose cohort is not allowed to commence until the Chairman of the outside drug safety monitoring board, a hepatologist, reviews the liver safety data from a minimum of 8 subjects from the current cohort that were dosed for a minimum of 8 weeks. One of the first signals of efficacy for Proellex is induction of amenorrhea. This has profound effects on symptoms of both uterine fibroids and endometriosis. The 3 mg cohort has 10 women currently on study with 8 women reaching at least the 8 week dosing point. Of those 8 women, 7 have appeared to cease menstruating based on their daily diaries. In the final analysis of the 1 mg group 5 out of 11 women stopped menstruating while taking the drug.