The Phase 2 ZP-204 study is a five arm dose escalation study in which up to 12 women with diagnosed endometriosis or uterine fibroids were randomized to 1, 3, 6, 9 and 12 mg doses of oral Proellex.
In the trial, a 24 hour pharmacokinetic assessment was made on the first day of dosing, and then women were assessed weekly in a single blind placebo run-in for up to 6 weeks in order to record their weekly changes in liver enzyme as well as their menstrual bleeding events and intensity.
The previous Phase 2 studies demonstrated that daily oral doses of 12.5 to 50 mg Proellex resulted in a dose dependent reduction in fibroid size, while 25 and 50 mg daily oral doses of Proellex showed changes in the pain endpoints of endometriosis.
The company intends to re-enter Phase 3 with low dose oral Proellex, based on the positive current data and the efficacy signal in its previous Phase 2 studies.