New drug increases biochemical pregnancy rate following IVF

Women undergoing IVF using donor eggs had a higher biochemical pregnancy rate after using a new drug designed to act directly on the endometrium in the uterus.

Twenty eight centres across Europe took part in the clinical trial to test the efficacy of the novel drug OXO-001 on improving embryo implantation and pregnancy rates. Researchers found that while biochemical pregnancy rates, where a positive pregnancy test is obtained, increased significantly, the study did not show a statistically significant increase in the live birth rate. Results were presented on 7 July in Amsterdam at the 40th annual meeting of the European Society of Human Reproduction and Embryology.

Dr Ippokratis Sarris, director and consultant in reproductive medicine at King's Fertility who was not involved in the research told BioNews: 'This is a fascinating proof-of-concept study of a novel therapeutic option, which is well designed and conducted by a wide collaboration of reputable clinics with a track record of good research. 

'In an era where fertility innovations have only produced marginal gains, any novel therapeutic intervention that might deliver such a large increase in live birth rate from cycle started will be staggering. Nevertheless, exciting as this might be, the current data is still preliminary and needs to be viewed with a healthy dose of restraint.'

A total of 96 women took part in the trial, undergoing embryo transfer, either after being given a placebo, or the new non-hormonal oral drug. Patients took the drug for one menstrual cycle before the cycle in which embryo transfer took place and continued until five weeks after embryo transfer. Women under the age of 40, with infertility, who had fewer than two embryo transfers that did not result in pregnancy previously, were eligible for the study.

Researchers showed that 75.9 percent of women who took the drug experienced a biochemical pregnancy, compared to 52.4 percent in the placebo group, and this was statistically significant. However, while an overall higher clinical pregnancy rate, (confirmation of pregnancy via ultrasound at six weeks), ongoing pregnancy rate (confirmation of pregnancy via ultrasound at 20 weeks), and live birth rate was observed in women who took the drug, these differences were not significant.  

The results presented showed that 42.6 percent of women who underwent a single embryo transfer experienced a live birth after using the drug, a 6.9 percent increase compared to 35.7 percent who took the placebo. Authors argued this was a clinically significant finding. They explained the trial had been designed to measure the effect of drug on embryo implantation success, and further research was needed to determine if it could affect live birth rate. The results of this study have not yet been peer-reviewed. 

Professor Nick Macklon, medical director of London Women's Clinic, who was not involved in the research told BioNews: 'Effective interventions to improve endometrial receptivity in IVF are still awaited and while these are preliminary data, they indicate that the intervention tested could help some women to conceive with IVF. It will be important to understand whether the treatment may also encourage poorly viable embryos to implant, leading to miscarriage. Future studies will clarify its effectiveness and the patients who may benefit.'