ObSeva has abandoned its Phase III trial evaluating nolasiban (IMPLANT 4) in women undergoing embryo transfer (ET) following in-vitro fertilisation (IVF).

The treatment fell short of its primary endpoint, which was an increase in ongoing pregnancy rate at 10 weeks, but all subjects will continue to be followed up to delivery and infant development will be assessed up to six months.

The randomised, double blind, placebo controlled clinical trial included 807 patients from more than 40 fertility clinics across nine European countries, and administered either a single 900 mg dose of nolasiban or placebo (1:1) four hours prior to ET.

The company is “extremely disappointed with these unexpected results, not in the least for the millions of women hoping to have a baby through IVF.”

Ernest Loumaye, chief executive officer and co-founder of ObsEva explained: “Based on these results, we have decided to discontinue the current nolasiban IVF program and will explore potential repositioning of the product candidate. We remain more committed than ever to developing our innovative pipeline of late-stage products aimed at unmet needs in uterine fibroids, endometriosis and preterm labor and will focus our resources on these programs immediately.”

The drug is question is an oral oxytocin receptor antagonist which was licensed from Merck KGaA in 2013. It’s a novel, orally administered GnRH receptor antagonist with a potentially best-in-class profile in late-stage clinical development for the treatment of heavy menstrual bleeding associated with uterine fibroids and pain associated with endometriosis.