January 9, 2026

expert reaction to OVO labs announcing efficacy data for its therapeutic (EmbryoProtect 1) to rejuvenate the human egg

An unpublished conference abstract and preprint from OVO labs claims to have rejuvenated the human egg. 

Prof Robin Lovell-Badge FRS FMedSci, Group Leader, Francis Crick Institute, said:

“If true, the claims made by Melina Schuh are obviously significant and of great importance to IVF for women with repeated problems of in vitro fertilisation failure and early miscarriage, but perhaps also generally as a means to improve IVF efficiency (which is generally around 30%). However, it is difficult to judge these claims on the rather limited data provided – none of which has been through peer-review as yet.

“The “Manuscript Preprint Abstract” from Melina Schuh states that: “ongoing transcription at centromeric and pericentromeric regions is required to maintain the cohesion protector Shugoshin 1 and the phosphatase PP2A at centromeres, thereby protecting centromeric cohesin during meiotic divisions.” The authors may have provided a novel link between two processes, both of which were known previously to be important for meiosis. If they have done this, the work is perhaps significant.

“But, centromeric transcription during meiosis in mice has been known to occur and to be important since at least 2021, e.g.:

https://pubmed.ncbi.nlm.nih.gov/34379093/

https://pubmed.ncbi.nlm.nih.gov/37035744/

And the roles of Shugosins and PP2A have been known for longer, but a clear link between Shugosin 2 (SGO2) and age-related aneuploidy is more recent:

“Age-dependent loss of cohesion protection in human oocytes: https://pubmed.ncbi.nlm.nih.gov/38134935/ (Adele Marston paper)

“The findings in this latter paper support a model where age-dependent decline in association of SGO2 with the pericentromere bridge makes pericentromeric cohesion vulnerable to premature loss, a major cause of age-related aneuploidy in humans. “It follows that the development of methods to preserve SGO2 may offer the potential to support fertility while reducing oocyte aneuploidy in women of older reproductive age.”

“However, this is where I get confused. It seems that SGO2 is relevant for meiosis whereas SGO1 is more important for mitosis (see below). It is unclear from the few details given in the Abstract and meeting notes and the press release why Melina Schuh’s lab focussed on the latter.

“As for the claims made in the conference abstract and press release about the efficacy of introducing their lead candidate EP1 into human oocytes, there is insufficient information for me to judge this. Moreover, a preclinical trial with only 100+ human eggs seems very minimal, especially as they were from women aged from 22-43, meaning on average only about 5 per year, and we are not given data on how success related to age. We are also not given any information about the types of fertility problem being experienced by the egg donors and whether the efficacy of the method varied among these. There is also no information provided about ‘safety’. Were embryos injected with EP1 all normal up to blastocyst stages? How would they assess safety beyond this? I assume that EP1 is based on Shugoshin 1 and PP2A, but no details are provided.”

Professor Richard Anderson, lsie Inglis Professor of Clinical Reproductive Science and Head of Section, Obstetrics and Gynaecology, University of Edinburgh, said:

“The most important factor in determining whether an IVF cycle results in a successful pregnancy is the ‘quality’ of the woman’s eggs, which is determined by her age. Over time, the bonds that hold chromosomes together loosen, so at the time of fertilisation the sorting then separation of chromosomes (known as segregation) gets less precise, resulting in failure of early embryo development through to miscarriage and fetal abnormalities, such as Down syndrome. Being able to treat eggs to make this process work better would be a huge advance, and is what Ovo Labs are claiming to be able to do. The details are rather sketchy, but their treatment targets a known protein involved in the process called Shugoshin 1, with apparently a large improvement in accurate chromosome segregation. This effect was even clearer in the eggs of older women.  While we await further details and confirmatory clinical trials, including addressing safety issues, these results have great potential for improving IVF success rates.”

The press release ‘Ovo Labs announces the first-ever rejuvenation of the human egg, aiming to address the high failure rate of IVF’ was under embargo until 00:01 Friday 9^th January 2025.

Declared interests

Prof Richard Anderson: “I have grant funding from the Wellcome trust to address cell division in the human oocyte.”

For all other experts, no replies to our request for DOIs was received.