Successful results for nolasiban from IMPLANT2 trial for improving pregnancy rate following in vitro fertilization.- ObsEva SA

ObsEva SA a clinical-stage biopharmaceutical company focused on the development and commercialization of novel therapeutics for serious conditions that compromise a woman�s reproductive health and pregnancy, reported positive top line results of the IMPLANT2 Phase III clinical trial of its oral oxytocin receptor antagonist, nolasiban, which is being developed for improving pregnancy rate following in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) procedures.

Importantly, infertility impacts approximately 10% of reproductive aged couples, and is influenced by the trend of pregnancy desired later in reproductive lives, with annual assisted reproduction technology (ART) cycles approximating 1.6 million worldwide. IMPLANT2 is a randomized, double blind, placebo controlled clinical trial that included 778 patients from 41 fertility clinics across 9 European countries. Patients received either a single 900 mg dose of nolasiban or placebo (1:1) orally on the day of embryo transfer (ET). Recruitment included patients undergoing single, fresh ET on day 3 (D3, n=388) or on day 5 (D5, n=390) after oocyte retrieval. The primary endpoint of the trial was ongoing pregnancy as determined by ultrasound at 10 weeks following ET. The pre-defined primary analysis was conducted on the pooled population of D3 and D5 ET. These top line results include efficacy and safety data up to week 10 of pregnancy following embryo transfer. Demographics and baseline characteristics were comparable between groups.

The primary endpoint of the clinical trial was met, with an absolute increase in ongoing pregnancy rate at 10 weeks of 7.1% (placebo 28.5% and nolasiban 35.6%, p = 0.031). This represents a relative increase of 25% in the ongoing pregnancy rate after administration of nolasiban compared to placebo. In the ET D5 subgroup, the absolute increase was 11.2% in favor of nolasiban (placebo 34.7% and nolasiban 45.9%, p = 0.034). This represents a relative increase in ongoing pregnancy rate of 32% after administration of nolasiban compared to placebo. In the ET D3 subgroup, there was a statistically non-significant 3.1% absolute increase in favor of nolasiban (placebo 22.2% and nolasiban 25.3%, p > 0.05), or a 14.0% relative increase in ongoing pregnancy rate after administration of nolasiban compared to placebo. In addition, nolasiban was well tolerated, with low rates of treatment discontinuation that were comparable between treatment and placebo. The safety profile of nolasiban was also similar to placebo, with a total of 9 (2.3%) serious adverse events (SAE�s) in the placebo group and 4 (1.0%) in the nolasiban group. None of these SAE�s were reported to be related to treatment.

Follow-up data from the IMPLANT2 study will include live birth rate, and 28-day neonatal safety, expected to be reported in the fourth quarter of 2018. Six-month infant follow-up is expected to be available in 2019.

Based upon the data, ObsEva intends to seek feedback from regulatory authorities in Europe and the United States on any necessary additional clinical requirements, and also solicit guidance on the regulatory registration path forward. ObsEva plans to provide an update on its expected nolasiban clinical and regulatory timelines following these discussions.