Back in November of 2013, BioNews Texas reported on how Woodlands-based Repros Therapeutics had received guidance from the United States Food and Drug Administration for its clinical trial on Proellex, a drug candidate for the treatment of uterine fibroids, with regard to endpoints that the company believed to be acceptable for the treatment. Since that time, Repros is now reporting that the company has made marked progress in the company’s bid to further develop and successfully commercialize their lead product Proellex. In a recent press release, Repros announced that it has received clearance and guidance from the FDA to begin a new round of clinical studies for oral Proellex in order to further test and develop the product.
Now that the FDA has offered guidance for Prollex, Repros will proceed to the next steps in the clinical process, which will include Phase 1 and 2 studies of oral Proellex® under two separate indications — endometriosis and uterine fibroids. During this time, the drug will still be designation on partial clinical hold.
Specified in the guidance by the FDA is that the highest allowed dose of oral Prollex in the upcoming trials will be 12 mg daily. In addition to the upcoming trials for the above mentioned INDs, Repros is also currently conducting a Phase 2 study for the use of Proellex in severe endometriosis. There are also plans to submit a Phase 2 protocol to test Prollex in the treatment of symptomatic fibroids.
Regarding the proposed uterine fibroid Phase 2 protocol, the guidance from the FDA specifically concerned appropriate inclusion and exclusion criteria for study subjects who will participate in the clinical trial, as well as the preferred efficacy endpoint to measure the drug’s success in the trial. With respect to uterine fibroids, the FDA-preferred efficacy endpoint will be the reduction in excessive menstrual bleeding among trial participants, with specific preferences in how researchers will determine changes in bleeding.
For their part, Repros intends to comply with the guidance from the FDA, and will also seek to collecting additional efficacy outcomes as the trials progress, which will include tumor size and relief in symptoms. The company also noted that, based on prior trial results with Proellex at 6 and 12 mg daily dosages, it “plans to enroll fewer than 75 women in a three arm, parallel design double blind trial,” according to a press release. “The study is sized to provide greater than 90% power in demonstrating efficacy associated with reducing subject bleeding.”