Helping bring phage medicines to UK patients – guidance for industry
Source: gov.uk (2025-06-05)

Bacteriophages – viruses that selectively fight bacteria – may offer new hope in fighting infections and tackling antimicrobial resistance.

The Medicines and Healthcare products Regulatory Agency (MHRA) has today (4 June) published the UK’s first official guidance to support the safe development and use of phage therapies – treatments that use viruses to target and destroy harmful bacteria.

The guidance aims to help researchers and companies develop phage-based medicines that meet UK safety, quality and efficacy standards, so they can be made available to patients who need them most.

It covers both combined phage products designed for common infections and circulating strains, as well as personalised phage therapies that are tailored for individual patients with rare or highly resistant infections.

For patients, this could mean access to phage treatment when standard-of care-antibiotics fail or cannot be given, for example due to allergies. While some patients in the UK have already received phage therapy under compassionate use – with phages imported from abroad – there are currently no licensed phage medicines on the UK market.

Lawrence Tallon, MHRA Chief Executive, said:

“Some infections are becoming harder to treat when antibiotics are ineffective against them – and patients urgently need new options.

“Phage therapy is one of several promising approaches. This guidance brings together relevant standards to provide clarity for researchers and companies, so they can develop these treatments safely and bring them to the people who need them.

“We’re committed to working with industry to support innovation in this space – without compromising on the robust safety and quality standards that patients rightly expect.

“It’s part of our wider mission to support innovation and make the UK a world leader in life sciences.”

Phage therapies use bacterial viruses – called bacteriophages – that attack specific bacteria without harming human cells. They have received increased interest in recent years as a potential way to treat antibiotic-resistant infections, with over 60,000 serious antibiotic-resistant infections estimated annually in the UK and growing.

The MHRA’s publication sets out how existing UK and international regulatory frameworks apply to phage treatments – from early research through to use in patients. It provides clear, practical advice on what’s needed at each stage of development – whether the goal is a fully licensed product or a treatment used under a clinician’s responsibility for an individual case.

Further detail in the guidance includes: - What evidence is needed to support clinical trials and market authorisation - How to meet standards on quality, safety and manufacturing, including the application of Good Manufacturing Practice (GMP) - How personalised treatments can be developed and supplied - When and how unlicensed phage treatments can be used for individual patients

The 28-page document brings together UK and international regulatory standards in one place, helping innovators clearly understand what’s required – and avoid unnecessary delays.

Julian Beach, MHRA Interim Executive Director of Healthcare Quality and Access, said:

“Developers have told us they need clarity on how phage therapies fit into the UK’s regulatory system. This helps signpost relevant requirements, providing that clarity. We continue to support innovation by working closely with industry and researchers while making sure patients are protected every step of the way.”

The publication supports the UK 2024-2029 National Action Plan to confront AMR and the MHRA’s wider role in enabling innovative, science-led regulation that meets public health need while maintaining high standards for quality and safety.

Dr Colin Brown, deputy director at the UK Health Security Agency, responsible for AMR, said:

“MHRA’s new guidance helps lay the foundations for phage therapy opportunities in the UK. It provides much-needed direction for scientists and researchers working to make this treatment a reality for patients.

“Phage therapy truly has the potential to transform the way we treat bacterial infections, especially as resistance to antibiotics grows. At UKHSA, we’re developing new ways to help increase phage therapy use and research, including a bacteriophage collection where scientists can both access and deposit phages. In time, we hope solutions like phage therapy can become a first-line treatment option.”

The MHRA developed the guidance with input from the Phage Innovation Network, a cross-sector group supported by Innovate UK, and from industry, clinicians and academic researchers.

Frederique Vieville, BEAM Alliance Phage ACT Lead, a European group supporting antimicrobial therapy development, and 5QBD-Biotech Chief Executive, a biotech company focused on bacteriophage therapies, said:

“As difficult-to-treat infections continue to rise, phage therapy is becoming an important complement to existing treatments. Recent steps have been taken by European regulators to outline the regulatory framework for phage-based medicinal products, but developers still need support to navigate it effectively. Clarity about the pathway – tailored to the unique characteristics of phages – is vital to help meet quality, non-clinical, and clinical requirements, and ultimately bring phage-based treatments to patients more efficiently.”

Dr Jason Clark, NexaBiome Director and Chief Scientific Officer, a company developing commercial phage therapies in the UK, said:

“There is an urgent and increasing need for new ways to treat antimicrobial resistant infections, with bacteriophage being at the forefront of recent developments. This new guidance from the MHRA is incredibly forward-thinking and puts the UK in pole position to fully realise the healthcare and commercial benefits of this exiting technology.

“As a Company developing bacteriophage products for human use, this guidance helps us to decrease perceived risks and gives clarity to the regulatory landscape, ultimately enabling us to more readily bring investment into the UK.”

Companies interested in developing bacteriophage treatments can access scientific advice from the MHRA at any stage of development.

Notes to editors
- For more information, access Regulatory considerations for therapeutic use of bacteriophages in the UK (https://gov.uk/government/publications/regulatory-considerations-for-therapeutic-use-of-bacteriophages-in-the-uk) on the MHRA website.
- Bacteriophages are naturally occurring viruses that infect specific bacteria. Unlike antibiotics, which can harm helpful bacteria too, phages typically target only one species or strain of bacteria. They work by attaching to the bacteria, injecting their genetic material, and destroying it. In medicine, phages can be tailored to attack the bacteria causing an infection, with less impact on the body’s healthy bacteria.
- Antibiotic resistant infections continue to rise - GOV.UK (https://www.gov.uk/government/news/antibiotic-resistant-infections-continue-to-rise)
- Confronting antimicrobial resistance 2024 to 2029 - GOV.UK (https://www.gov.uk/government/publications/uk-5-year-action-plan-for-antimicrobial-resistance-2024-to-2029/confronting-antimicrobial-resistance-2024-to-2029#theme-2---optimising-the-use-of-antimicrobials-1)
- The Medicines and Healthcare products Regulatory Agency (MHRA) is responsible for regulating all medicines and medical devices in the UK by ensuring they work and are acceptably safe. All our work is underpinned by robust and fact-based judgements to ensure that the benefits justify any risks.
- The MHRA is an executive agency of the Department of Health and Social Care.
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