ISSCR requires expanded oversight of embryo models, bans ectogenesis

The International Society for Stem Cell Research (ISSCR) has updated its Guidelines, expanding oversight requirements for research involving human stem-cell-based embryo models (SCBEMs) and prohibiting the use of human SCBEMs to achieve ectogenesis.

The update to to the Guidelines for Stem Cell Research and Clinical Translation implements recommendations published recently by the ISSCR's Embryo Models Working Group (see BioNews 1293), following a year of deliberation (see BioNews 1289). The update also adopts an approach consistent with the UK's Code of Practice for the Generation and Use of Human Stem-Cell-Based Embryo Models (the SCBEM Code of Practice) – a document published jointly by PET (the Progress Educational Trust) and Cambridge Reproduction (see BioNews 1246a, 1246b and 1247), which is cited in the Working Group recommendations.

Hideyuki Okano, president of the ISSCR, said: 'SCBEMs are transforming how we study early human development, and it is critical that this progress is supported by clear guidance, a strong sense of responsibility, and global consensus. I commend the ISSCR Embryo Models Working Group for their thoughtful and forward-looking leadership in ensuring our Guidelines evolve in step with this rapidly advancing field.'

Until now, the ISSCR has updated its Guidelines in their entirety every few years, with the previous update published in 2021 (see BioNews 1097 and 1098). However, this Iatest update is a 'targeted update', confined to those parts of the Guidelines that concern SCBEMs. The ISSCR explained: 'This focused approach enabled the ISSCR to respond thoughtfully to a defined scientific and oversight need, and to offer updated international guidance for researchers, journal editors, regulators, funders, and the public.'

Updated definitions in the Guidelines stipulate not only that a SCBEM 'models or recapitulates key stages of embryonic development', as was the case previously, but also that a SCBEM models or recapitulates 'in 3D' and is 'designed to model specific phenotypic features and developmental processes'. Meanwhile, the terms 'integrated' and 'non-integrated' – used previously in the Guidelines to distinguish between different types of SCBEM – have now been dispensed with, and are mentioned only as terms that were 'used by the scientific community to describe SCBEMs from 2021-2025'.

One consequence of these revisions is that the class of SCBEMs that requires dedicated oversight has been expanded. Previously, the ISSCR Guidelines required only research that involved 'integrated' SCBEMs to be 'reviewed by a specialised oversight process'. Now, the Guidelines require all research that involves SCBEMs (as they are now defined) to receive such specialised oversight.

An additional change is the inclusion of an explicit prohibition on using human SCBEMs to (seek to) achieve ectogenesis. Previously, the list of 'Prohibited research activities' in the Guidelines included 'Transfer of human SCBEMs to the uterus of either a human or animal host'. This wording has now been amended to refer specifically to a 'living' human or animal host, and to further prohibit 'culture in an artificial in vitro system designed to develop SCBEMs to viability (ie, ectogenesis)'.

'This thoughtful update to the ISSCR Guidelines helps to clarify what is required of researchers who work with SCBEMs,' said Sandy Starr, deputy director of PET and project consultant for the SCBEM Code of Practice. 'In the UK, funding is being sought to establish a SCBEM Oversight Committee and a SCBEM Register, as proposed in the SCBEM Code of Practice. These governance structures, once established, will be capable of meeting the updated ISSCR requirements in full.'