ObsEva SA announced the publication of two peer-reviewed papers on nolasiban, an oxytocin receptor antagonist in development for improving live birth rates in women undergoing embryo transfer following in-vitro fertilization (IVF). The study reports the results from a meta-analysis of three randomized, placebo-controlled trials showing that nolasiban increased the likelihood of live birth following IVF. Participants were administered a single oral dose of nolasiban 900 mg (n=846) or placebo (n=864) and assigned to one of three trials (IMPLANT 1, IMPLANT 2 and IMPLANT 4) conducted in Europe and Canada between 2015 and 2019. Key outcomes of the study were as follows: The Phase 2 IMPLANT1 and Phase 3 IMPLANT 2 trials both demonstrated that administration of a single 900 mg dose of nolasiban administered before fresh single embryo transfer (SET) increased live birth rates compared to placebo. These results were not confirmed in a third trial, IMPLANT 4. A patient-level combined analysis of the three studies showed a 5% absolute increase (15% relative increase) in ongoing pregnancy rate, with an odds ratio for nolasiban versus placebo of 1.25 that was statistically significant (p=0.029). The analyses also showed that the effect size for nolasiban was similar for ongoing pregnancy rate and live birth rate. Population pharmacokinetic analyses indicated that higher exposures of nolasiban were associated with a higher probability of pregnancy. Nolasiban was well tolerated at a dose of 900 mg and there were few differences in maternal, obstetric and neonatal outcomes between the nolasiban and placebo treatment groups. The study focused on nolasiban’s impact on uterine contractions, endometrial perfusion and endometrial mRNA expression. Key outcomes of the study were as follows: Both doses of nolasiban showed trends of decreased contraction frequency and increased endometrial perfusion. At 1800 mg, 10 endometrial genes were significantly differentially expressed, including three genes (DPP4, CXCL12 and IDO2) believed to be associated with decidualization and endometrial receptivity. Nolasiban was well tolerated, supporting testing at higher doses in IVF patients.