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A good companion for the long journey - companion diagnostics in the UK

on Thursday, 15 February 2024.

In the consultation concerning the reform of UK medical device regulation and the Government's published response to it, there are suggestions that the conspicuous absence of regulation and guidance on companion diagnostics will be fixed.

Thinking about the drive for personalised medicines (nutcrackers rather than sledgehammers), and given the increasing prevalence of advanced therapy medicinal products, companion diagnostic medical devices are likely to make an appearance in the care pathways of an increasing proportion of patients. It is therefore a bit weird (sorry, not a legal term) that the current UK regulations governing medicines and medical devices do not mention companion diagnostics.

The consultation on changes to UK medical device regulation contained specific questions on companion diagnostics, and the Government's published response to that consultation provided some useful indications about what is coming. Having reviewed the response to the consultation, the Government has pointed towards the following:

  • On the question of whether companion diagnostics should be treated differently to other in vitro diagnostic medical devices, the response was not a strong one, but the respondents gave the MHRA some food for thought. It is unlikely that the reforms will involve major new regulations specific to companion diagnostics, but some specific issues will be dealt with.
  • The regulations (Medical Devices Regulations 2002) will be amended to introduce classification rules that apply specifically to companion diagnostics. The MHRA will take into account the classification approaches of the EU (meaning the In Vitro Diagnostics Regulation 2017/746 (IVDR)) and the International Medical Device Regulators Forum (IMDRF).
  • The amended classification rules will reflect a risk-based approach to the clinical evidence requirements relating to companion diagnostics. It is expected that the MHRA will provide guidance on each classification, which will be intended to help clarify the applicable clinical evidence requirements and give sponsors a better understanding of what proportionate approaches are acceptable. The Government's response suggests that the MHRA understands that this will require more than a simple differentiation between devices that predict treatment benefit and those that predict toxicity.
  • In general, performance studies involving companion diagnostics will remain subject to the same requirements as all other performance studies.
  • Performance studies involving companion diagnostics using only left-over samples will need to be notified to the MHRA.

The Government's responses relating to IVDs indicate some reform themes that will be relevant to companion diagnostics and other IVDs, including:

  • Performance study roles, conditions and requirements, and accompanying guidance
  • Clinical and analytical performance study reports
  • Bias, inclusion and ethical review
  • Invasive sampling
  • Subject withdrawal rights

The Government has said it will look at the EU IVDR. It has also generally proposed to take international approaches and standards into account. However, reading between the lines, it has been reluctant to commit to aligning to anything or any territory in particular. The Government's response shows a general preference for making the requirements clear in robust legislation rather than leaving too much either too rigid standards or to more flexible (but perhaps less predictable) regulatory guidance. To date, the MHRA has published precious little on companion diagnostics, so, at the very least, we can expect some legislation and some guidance.

For a product that is a combination of a medicinal product and a medical device in one item, the regulations in the UK and EU have some provisions that attempt to clarify what requirements apply and remove the full application of both regimes. This would not work for companion diagnostics because the diagnostic and its related medicine are separate items. But, the indication from the MHRA is that a risk-based proportionate approach should become the norm.

There are moving parts in the UK regulatory environment, but if you put them together, the direction of travel is clear. The Government and NHS believe in the power of diagnostics to improve healthcare in the UK; major reforms are in progress, some of which will have a significant impact on companion diagnostics; and, although the UK will look to the EU and international approaches, it is keen to stand out.

The next thing to look out for is the 'IVD Roadmap' and the stakeholder discussions on the anticipated future core regulations. If the Government's roadmap is anything to go by, 2024 will be a full and exciting year.


Are you developing a companion diagnostic medical device and planning the commercialisation of that device and the medicine to which it relates? Please contact Harry Hamilton Jennings in our Pharmaceuticals and Life Sciences team on 07789 533 122, or complete the form below.