Biopharmaceutical firm ObsEva will end the current clinical development programme of nolasiban IVF after the drug failed in the Phase III IMPLANT 4 clinical trial in Europe.

Nolasiban is an oxytocin receptor antagonist intended to increase the pregnancy rate in women receiving embryo transfer (ET) following in-vitro fertilisation (IVF).

ObsEva licensed the drug from Merck in 2013 and holds the exclusive global commercialisation rights.

The randomised, double-blind, placebo-controlled IMPLANT4 trial was performed in 807 patients from more than 40 fertility clinics in nine European countries.

A single dose of 900mg nolasiban or placebo was given four hours before ET in women receiving a day-five transfer of a single, fresh embryo. The primary endpoint was ongoing pregnancy, determined using ultrasound at ten weeks following ET.

The trial failed to meet the primary endpoint of a rise in ongoing pregnancy rate at ten weeks, with 40.5% of participants on nolasiban experiencing an ongoing pregnancy versus 39.1% of those on placebo.

Data showed that the drug was well-tolerated. ObsEva said that all participants will be followed up to delivery and infant development will be monitored up to six months.

ObsEva CEO and co-founder Ernest Loumaye said: “Based on these results, we have decided to discontinue the current nolasiban IVF programme 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 labour and will focus our resources on these programmes immediately.”

ObsEva initiated the IMPLANT 4 trial in Europe, Canada and Russia in November last year. The trial was conducted in a total of 49 clinical sites across ten countries.

The company secured US Food and Drug Administration (FDA) clearance last month to conduct the Phase III IMPLANT 3 trial of nolasiban in the US.