Genome editing in medicine - where are we?

By Laura Blackburn

14 March 2017


As we discussed in a recent blog, the House of Commons Science and Technology Committee's ambitious and wide-reaching inquiry into genomics and genome editing is examining the role that genomic technologies can play in health, agriculture and the environment. The PHG Foundation's written response to the inquiry was one of many sent, and the variety of organisations and individuals responding resulted in an in-depth treasure trove of opinion. These responses also provide a valuable insight into what the external community currently think about a range of topics, in particular queries and concerns surrounding the use of genome editing in healthcare. 

Support for research, drug discovery and innovative therapies

There was general support for the use of genome editing as a research tool, not least in drug discovery; in many cases technologies such as CRISPR-Cas9 have increased the speed at which research can be carried out. The use of genome editing in medicine – to edit somatic (i.e. non germline) human cells either inside or outside of the body for therapeutic use was also broadly supported, subject to appropriate safeguards being in place.

Genome editing is not exceptional and we can make use of the work that has already been done in understanding the issues such as safety and ethics surrounding the use of innovative therapies.

A few respondents pointed out that many of the safety and ethical challenges facing genome editing are the same as for other innovative technologies, such as any form of gene therapy. As such, they noted, genome editing is not exceptional and we can make use of the work that has already been done in understanding the issues such as safety and ethics surrounding the use of innovative therapies.

Regulatory concerns and opportunities

It was clear that respondents are concerned about regulation: how innovative therapies will be regulated and whether current guidelines are fit for purpose. Many highlighted the need for dialogue between all stakeholders and the regulators, and also the uncertainty about where to get the most up to date advice and what the impact of personalisation of therapy will have on clinical trial design. Novel approaches to trial design and flexible regulatory frameworks were a recurring theme; a few responders pointed out that Brexit could be an opportunity for the UK to become more nimble in terms of developing strong and proportionate regulation that focuses on the end product and its use, rather than the process used to make it. The issue equity of access was also raised; a national commissioning framework was proposed as one way to ensure access not only to molecular diagnostics, but also to innovative medicines. 

Resistance to germline editing

As expected, many of the responses focused on the use of germline editing – of eggs, sperm or embryos – and concerns about the ethics of this approach. Many highlighted the importance of distinguishing between somatic genome editing and germline genome editing. While there was broad support for the former in an appropriately regulated environment to treat diseases with unmet clinical need, there was a lack of support for clinical germline editing. 

Some responders thought that genome editing of embryos was appropriate in a research context (as has already been approved by the Human Fertilisation and Embryology Authority (HFEA)), whilst others want the practice banned outright. Regardless of their stance, most organisations who submitted an opinion on this issue to the Inquiry highlighted the importance of public debate, with many mentioning the HFEA engagement process on mitochondrial donation as a model to follow for the future. 

US National Academies support germline editing

Resistance to the use of germline genome editing in human embryos stands in marked contrast to the recent report on the same issue from the US National Academies of Sciences, Engineering and Medicine. In an apparent about-turn from earlier policy positions, the report recommended that human germline editing should be permitted 'under stringent oversight' to treat genetic diseases for which there is no other known cure. These conclusions are surprising, given that the summit on human gene editing held in December 2015 concluded that clinical germline gene editing should not be permitted, but that the topic should be revisited as scientific knowledge and societies' views evolve. The current recommendation is quite a leap, given that this meeting was only 15 months ago. 

By saying that germline editing is theoretically permissible, they are starting the conversation on if, how or why it should be permitted

By arriving at this decision, the National Academies state that they are providing guidance for everyone, including those countries that do not currently have any regulations in place. There is an element of pragmatism to this approach, given that germline editing might be available in the future in countries without safeguards, and patients may travel to access them regardless. By saying that germline editing is theoretically permissible, they are starting the conversation on if, how or why it should be permitted, and gives us a head-start in developing appropriate laws and regulations. 

However, they do say that germline editing should only be used when there is 'no reasonable alternative'. In many cases, we have reasonable alternatives to help people have children e.g. pre-natal screening, preimplantation diagnosis and other reproductive technologies to select healthy embryos. Ethical issues notwithstanding, given other techniques at our disposal, for many conditions the question is less 'should we?' but 'why would we?' Despite this, the report authors believe that we should start talking about this, while this type of editing is still not technically possible and we have time to fully consider the potential consequences.  

Preparing for primetime

It is vital at this stage that we both continue the public debate about the use of genome editing technologies, and get our regulatory house in order, so that there are not unnecessary delays in trialling innovative therapies and making them available to patients when appropriate. As the PHG Foundation consultation response noted, 'the relative ease of using these technologies makes effective regulation challenging', but innovative therapies are already in clinical trials with more planned, so we must be ready. Maintaining public confidence in innovative science and healthcare means that we must pay careful attention to safety issues, ethical and societal concerns, ensuring public dialogue forms part of this process, alongside rapid scientific and clinical development.  This is a big enough ask at the national level; efforts to achieve harmonised international regulation will be even harder but, again – now is the time to be talking about it.

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