The UK's medicine regulator, the Medicines and Healthcare products Regulatory Agency (MHRA), has published a new position paper clarifying the licensing route for "promising" new microbiome-based medicines.
The new paper also encourages developers to pursue UK licensing pathways.
No microbiome-based medicine currently holds a UK marketing authorisation, though some other countries have authorised a small number of donor-derived microbiota products for Clostridioides difficile (C. difficile) infection.
The news follows the EU's Substances of Human Origin (SoHO) Regulation becoming fully applicable in early August, replacing older directives and setting strict, unified quality and safety standards for intestinal microbiota interventions.
Microbiome-based medicinal products (MBMPs) contain microorganisms as the active product and treat disease through modulating, restoring or replacing the human microbiome.
The MHRA called them a "promising new category of therapies" with the potential to address areas of significant unmet clinical need — including antimicrobial resistance (AMR).
The MHRA's position paper outlines how this class of medicine can be made available to patients in the UK while maintaining the "same robust standards of quality, safety and efficacy that apply to all medicines in the UK."
The regulator said MBMPs fall within the scope of the existing UK medicines regulatory framework, set out in the Human Medicines Regulations 2012.
Depending on their characteristics, MBMPs may be regulated as biological medicinal products or, in some cases, may meet the criteria for advanced therapy medicinal products (ATMPs).
The new position paper sets out key scientific and regulatory steps developers should consider, including the following:
- product characterisation
- manufacturing consistency
- control of batch-to-batch variability
- safety assessment (including AMR risk)
- and generation of robust clinical evidence.
Julian Beach, Executive Director of Healthcare Quality and Access at the MHRA, called MBMPs "one of the most interesting and fast-moving areas in medicine today."
He added: "Our position paper gives developers the clarity they need to bring these innovations forward with confidence, while ensuring patients continue to be protected by the same rigorous standards that underpin all licensed medicines in the UK."
The UK's existing, proportionate and evidence-based licensing frameworks are ready to support this field. Early engagement with us is the best way for developers to navigate it successfully.
The MHRA also added that developers should use its Innovation Office and Scientific Advice services early to clarify the applicable regulatory framework, agree proportionate development strategies and de-risk investment decisions ahead of pivotal trials.
The new position paper also clarifies existing arrangements for faecal microbiota transplantation (FMT) in the UK.
FMT is currently used for specific indications — including recurrent Clostridioides difficile infection — and is supplied either through clinical trials or as an unlicensed medicine under the "specials" manufacturing arrangements or extemporaneous preparation.
The MHRA said that these routes would remain the prescribing clinician's direct responsibility and are unaffected by the position paper.
