A pill for infertility

Oxolife, the female fertility biotech focused on enhancing embryo implantation in women undergoing assisted reproductive technology (ART) fertility treatment, recently presented successful phase 2 clinical data on its fertility pill OXO-001 at the European Society of Human Reproduction and Embryology (ESHRE) 40th Annual Meeting held in Amsterdam.

OXO-001 is a first-in-class, non-hormonal drug that acts directly on the endometrium – the inner lining of the uterus – to make it more conducive to embryo implantation. Failure of viable embryosto implant is a major reason why so many rounds of in-vitro fertilisation (IVF) and intracytoplasmic sperm injection (ICSI) do not result in pregnancy, and consequently a major cause of heartache among those trying for a baby. Taken twice daily, starting one menstrual cycle before embryo transfer and then for five weeks after transfer, OXO-001 is designed to reduce that distressing possibility.

Recently, Oxolife presented highly promising new data at ESHRE from its proof-of-concept Phase 2 double-blinded, randomised controlled trial of OXO-001, in which it was tested against a placebo pill.

An exploratory subset analysing 96 women up to 40 years of age, who all underwent single embryo transfer using donor eggs, found OXO-001 resulted in a large and statistically significant improvement in the biochemical pregnancy rate (early detection of pregnancy). While 52.4% of those who received the placebo (22 of 42) had a biochemically confirmed pregnancy, among those who received OXO-001
the rate was 75.9% (41 of 54).

There were also clinically meaningful improvements in:

• the clinically confirmed pregnancy rate (foetal heartbeat five weeks after embryo transfer) –
  50.0% for OXO-001 vs. 35.7% for placebo;
• the ongoing pregnancy rate (10 weeks post-embryo transfer) – 46.3% vs. 35.7%;
• the live birth rate – 42.6% for OXO-001 vs. 35.7% for placebo.

The Phase 2 trial was not powered to confirm that the differences for these outcomes were statistically significant. However, the data generated strongly supports advancement to Phase 3 confirmatory trial. Results of the Phase 2 trial are due to be published soon in the highly-regarded journal Human Reproduction.

Agnès Arbat, Chief Executive Officer, Oxolife, said: “Most rounds of IVF or ICSI still end in failure – many, because a viable embryo does not implant. A simple-to-take pill that materially improves the chance of success would therefore be of huge benefit to those who want a baby. This proof-of-concept phase 2 study shows that hope is now a step closer. Physicians and patients tell us that they consider a five percentage-point improvement in the ongoing pregnancy rate after IVF / ICSI to be clinically meaningful, so to achieve double that is amazing. This study was purposefully designed to include only women who used donor eggs so it could single out the true effect of OXO-001 on the endometrium.

“However, we believe OXO-001 has the potential to work equally well in those using their own eggs, and we are already planning a pivotal Phase 3 clinical trial in this more extensive group to support product registration.”

Professor Dr Karen Sermon, Chair of ESHRE, who was not involved in the study, commented: “Despite continuous developments in ovarian stimulation, embryo manipulation and culture, improving live birth rates in medically assisted reproduction has been incremental at best. A jump of nearly seven percentage points is very good news for our patients, and hopefully this can be confirmed in larger patient groups.”

OXO-001 works directly on the endometrium to encourage the embryo to stop rolling, to invade endometrial tissue, and to complete implantation. Extensive preclinical testing, plus clinical testing in 300 women to date, has shown it has an excellent safety profile. It is rapidly absorbed and expelled by the woman’s body within 24 hours after administration. In follow-up of babies six months after birth, all demonstrated normal development with no differences compared to placebo.

About one in six women of childbearing age has trouble conceiving [1], while use of fertility treatment is increasing worldwide as couples delay childbearing. Latest figures compiled by ESHRE[2] indicate around four million ART cycles are now performed globally each year, resulting in about one million babies. However, recurrent embryo implantation failure remains a significant challenge[3].

References:

1 https://www.cdc.gov/nchs/fastats/infertility.htm
2 ESHRE ART fact sheet 10, November 2023
3 Cimadomo, D., Craciunas, L., Vermeulen, N., Vomstein, K., & Toth, B. (2020). Definition, diagnostic and
therapeutic options in recurrent implantation failure: An international survey of clinicians and embryologists.
Human Reproduction, 36(2), 305–317. https://doi.org/10.1093/humrep/deaa317

Staff Writer