A trial of a new fertility drug has shown that it could improve the rate of embryo implantation during IVF and lead to a 7% increase in live births.
The pill, known as OXO-001, is designed to act directly on the lining of the womb to make it more receptive to the embryo being implanted. The findings raise hope for patients who have experienced repeated implantation failures during successive rounds of IVF.
“We are thrilled with the results of this trial, which highlight OXO-001’s potential to become the first therapeutic treatment to increase embryo implantation success, with a non-hormonal drug using a new mechanism of action, acting directly on the endometrium,” said Dr Ignasi Canals, chief scientific officer at Oxolife, the Spanish biotech company behind the trial, which is due to be presented at the European Society of Human Reproduction and Embryology’s 40th annual meeting in Amsterdam on Monday.
Success rates in IVF have steadily improved thanks to advances in egg collection, the cultivation of embryos and the selection of those most likely to yield a successful pregnancy. But there has been less progress in ensuring that the pregnancy progresses once the embryo is transferred.
Implantation is a crucial milestone in pregnancy and involves an intricate sequence of signalling between the embryo and the lining of the womb. Oxolife has not revealed how OXO-001 works beyond saying that it “enables the expression of key molecules that allow the embryo to stop rolling [across the womb’s surface], to invade and complete implantation”.
The latest study, performed across 28 centres in Europe, involved 96 women aged up to 40 who underwent a single embryo transfer during fertility treatment. The tests were randomised and double-blinded, with 42 women receiving placebo and 54 receiving a daily dose of OXO-001. Treatment began one menstrual cycle before the embryo transfer and continued until five weeks afterwards.
Those taking the drug had significantly higher rates of biochemical pregnancy compared with the placebo group (76% v 52%). The benefits continued to be seen in rates of heartbeat detected at10 weeks (46% for OXO-001, 36% for placebo) and for live birthrates (43% v 36%).
The drug did not appear to have negative side effects and, in the six-month follow-up, the babies had healthy development and showed no differences with the placebo.
Prof Richard Anderson, head of obstetrics and gynaecology at the University of Edinburgh, who was not involved in the trial, said the results were impressive. “It’s very meaningful to get a 7% difference in live birthrate with a simple oral medication in live birthrate,” he said. “It looks very exciting and it raises the question of whether it would help natural conception.”
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The company is also investigating the potential for the same drug as a treatment for polycystic ovary syndrome.
Prof Karen Sermon, chair of ESHRE, said: “Despite continuous developments in ovarian stimulation, embryo manipulation and culture, improving live birthrates in medically assisted reproduction has been incremental at best. A jump of nearly 7% is very good news for our patients, and hopefully this can be confirmed in larger patient groups.”
