How can we regulate embryo model research without stifling it?

While the science is currently in its infancy, there is future potential for these models to be increasingly similar to human embryos. Embryo model research offers exciting opportunities to better understand early human development, causes of infertility, miscarriage and diseases with developmental origins. However, we are also confronted by a regulatory lacuna because at present, it is widely accepted that these models do not fall within the legislative definitions of ‘embryo’. And as such, they fall outside the licensing regime governed by the Human Fertilisation and Embryology Authority (HFEA), and the requirement to cease growing an embryo beyond 14 days in the lab.

UK laws allow research on human embryos when there is benefit to patients and science, but it is subject to strict controls. Should these controls apply to embryo models, or does their lab-based origin or other features mean they should be subject to different protections? And if they are to be treated differently, what should that look like?

These are some of the questions I am working through as part of a project with the Nuffield Council on Bioethics (NCOB). As Chair of the project working group, I can say that our task is being made difficult by four main factors – first, the matter of language. What should we be calling these models? ‘Human stem cell-based embryo models’ is a mouthful, but many argue that other possibilities such as ‘synthetic embryo’ can be misleading.

Second, the science is still emerging, meaning developing hard laws for its governance could risk disproportionately inhibiting research that could bring significant benefits. This is a reason why current approaches have focused on forming soft laws. In 2021, the International Society for Stem Cell Research recommended that research using embryo models be subject to review, approval and monitoring through a specialised oversight process. And earlier this year, a new Code of Practice was published in the UK, which also advised that all embryo models be subject to ethical review by an Oversight Committee. While there are benefits to soft law regulation as it offers more flexibility and tends to have sector buy-in because it is developed bottom-up, it is not binding so, the question of adherence lingers.

Third, there are a range of embryo models that stem cells are being used to create. Categorising them is very difficult because there is a strong likelihood that new classifications will make better sense as the science develops. However, it is fair to say that some of these models are more complex than others and so regulating them all equally could be disproportionate and prevent society benefiting from the research.

And one final complicating factor is that there is a range of UK regulators that may have an interest in aspects of embryo model research, their development and future application. For example, the HFEA regulate embryo research and may by extension feel like a natural fit. However, the Steering Committee of the UK Stem Cell Bank oversees stem cell lines originating from embryonic stem cells and the Human Tissue Authority regulates tissue and cells. So, there could be a case of overlap here, warranting a more collaborative regulatory approach to embryo models.

As the summer reaches its end and our November publication date approaches, my team and I will continue to analyse the evidence and insights available, and to stress-test our draft recommendations. We will be considering the merits of both soft and hard law initiatives and what structures might be needed in future as the science advances. Our hope is to provide ethical insights that can assist those who have difficult decisions ahead of them.