May 26, 2024

Third global summit on human genome editing: Moving on after the He experiment

The much anticipated Third International Summit on Human Genome Editing was held in London earlier this month to explore the advances of the science, challenges and opportunities in research, regulation and equitable access to human genome editing technologies and treatments. It was organised by the World Academy of Sciences, Royal Society (UK), Academy of Medical Sciences (UK) and the National Academies of Sciences and Medicine (US).

Five years ago, at the second summit on human genome editing in Hong Kong, scientists responded with shock to  Dr He Jiankui’s announcement of the world’s first births of genome modified babies. His work raised serious concerns about scientific practice and ethical accountability.

Heritable genome editing involves making changes to embryos or gametes (sperm and eggs) that are passed down to subsequent generations. There are unpredictable effects and unintended consequences. While genome editing on human embryos for research purposes has significant potential and has been promoted by research groups, it is universally agreed that it is premature to pursue this technology for clinical applications (as opposed to research purposes).

The summit focussed on several crucial issues including the updates on the advances of the technology, equitable access to “somatic” treatment and ethics. Ethical aspects of the technology did not seem to be focus of the summit.

On the first day of the summit), there were updates on China’s regulation following Dr He’s controversial experiment. New regulations, Measures for the Ethical Review of Life Science and Medical Research Involving Humans, cover research institutions including work on human tissues, organs and embryonic cells. While these extensive legal developments were mostly positive, one of the speakers, Dr Joy Zhang of Kent University, in the UK, an expert on the governance of genome editing in China, expressed concerns that the laws do not apply to private organisations.    

On the third day, Professor Leigh Turner, a bioethicist from University California, Irvine, warned about unscrupulous clinics proffering untested interventions in the guise of established therapies. Turner drew from scholarship on the global marketplace for unproven and unapproved stem cell interventions to suggest that comparable businesses might advertise gene therapies that are not backed by convincing evidence of safety and efficacy.

Contacted following his presentation, Turner stated,

“Many regulatory bodies are understaffed, underfunded, and struggle to offer robust responses when businesses sell interventions without first testing them in clinical trials and generating meaningful evidence in support of their clinical use and regulatory approval. I’m concerned we might see clinics take advantage of hyperbole and enthusiasm surrounding genome editing and market purported ‘gene therapies.’ Countries need to provide sufficient resources for their regulatory agencies. In addition, to avoid the emergence of regulatory gaps and grey zones in the global marketplace, efforts to promote regulatory harmonization should continue.”   

At the conclusion of the summit, the organising committee issued a statement. First, it was encouraging that there have been significant advances made in somatic human genome editing, signifying it could treat incurable illnesses. Somatic genome are non-reproductive cells (cells other than sperm, eggs and embryos). Modifications made in these somatic cells affect only the patient who receives the editing. There are several clinical trials using somatic genome editing with preliminary positive results. To realise its therapeutic potential, the committee stated that it is necessary to conduct further research to increase the range of diseases it can treat and also to better understand the risks as well as unintended effects. Moreover, long-term follow-up of the patients is crucial to appreciate the effects of edit and to ascertain unintended consequences.

But the astronomical costs of somatic gene therapies are not sustainable. Thus, there is a need for an international commitment to affordable and equitable access to these medical treatments. The expenses and infrastructure need of gene treatments are not manageable for either patients or healthcare systems. Thorough planning is needed from the earliest phases of the research and development for each potential application.

Furthermore, there is a need to ensure that studies involve genetically diverse communities and diverse researchers. This will play a crucial role in achieving equitable outcomes.

There is a huge proportion of patients who live in developing nations with inadequate infrastructure. To set up sustainable access to safe interventions for research participants and patients, knowledge transfer between countries, improved clinics and research resources and stringent oversight are necessary.

Health care systems and the international health community should prepare to provide patients with affordable and evidence-based therapies. Treatments based on somatic genome editing that could help meet these needs was recommended as a priority for research investment.

The controversial heritable human genome editing remains unacceptable at present. This raises the possibility of making permanent changes to a person’s genetic make-up that will be passed down to their offspring. Preclinical evidence for both safety and efficacy of heritable genome editing has not been established. Moreover, community debate has not been determined. Thus, public debates should be ongoing in order to resolve whether this technology should be used. The current regulatory frameworks and ethical use of heritable genome editing are not in place. Regulatory measures for human genome editing need to protect ongoing, legitimate studies.

However, studies on genome editing in human embryos have continued with the objective of understanding early human development as well as determining the effective techniques to modify gene variants. Also, there have been improvements in research on deriving gametes (sperm and eggs) from stem cells and the committee encouraged research in this area.  

Compared to the second summit, this one is less scandalous and indeed the focus has moved on.

Patrick Foong