A trial of a new fertility drug has shown it can improve the implantation rate of embryos during IVF and lead to a 7% increase in live births.
The pill, called OXO-001, is designed to work directly on the lining of the uterus to make it more receptive to an implanted embryo. The results offer hope to patients who have experienced repeated implantation failure during successive IVF cycles.
“We are delighted with the results of this trial, which highlight the potential of OXO-001 to become the first treatment to increase the success of embryo implantation, with a non-hormonal drug that uses a novel mechanism of action, acting directly on the endometrium,” said Dr Ignasi Canals, chief scientific officer of Oxolife, the Spanish biotech company behind the trial, whose results were presented at the 40th annual meeting of the European Society of Human Reproduction and Embryology in Amsterdam on Monday.
Success rates for IVF have steadily improved thanks to advances in egg collection, embryo culture and selection of embryos most likely to result in a successful pregnancy. But there has been less progress in ensuring that pregnancy progresses once the embryo has been transferred.
Implantation is a critical stage in pregnancy and involves a complex sequence of signals between the embryo and the uterine lining.
Oxolife has not disclosed how OXO-001 works, saying only that it “enables the expression of key molecules that allow the embryo to stop rolling across the surface of the uterus, invade and complete the implantation process.”
The latest study, conducted at 28 centers in Europe, included 96 women up to 40 years old who underwent a single embryo transfer during fertility treatment.
The trials were randomized and double-blind, with 42 women receiving a placebo and 54 women receiving a daily dose of OXO-001.
Treatment begins one month before embryo transfer and continues for up to five weeks after.
Those who took the new drug had significantly higher rates of chemical pregnancy than the placebo group (76% vs. 52%). The benefits continued to be seen in heart rates detected after 10 weeks (46% for OXO-001 vs. 36% for placebo) and live birth rates (43% vs. 36%).
The drug did not appear to have any negative side effects, and at the six-month follow-up period, the children had healthy growth and showed no differences with the placebo.
Professor Richard Anderson, head of obstetrics and gynaecology at the University of Edinburgh, who was not involved in the trial, said the results were impressive. He said: "It is very significant to get a 7% difference in live birth rate with a simple oral drug in the live birth rate. It is very exciting and raises the question of whether it will help in natural conception."
The company is investigating the possibility of using the same drug as a treatment for polycystic ovary syndrome (a hormonal disorder common among women of reproductive age).