The European Medicines Agency (EMA), through its Committee for Medicinal Products for Human Use (CHMP), has released a draft concept paper announcing the development of a dedicated reflection paper on the non-clinical development and evaluation of microbiome-based medicinal products (MMPs). The goal is to capture “current thinking” and drive a harmonized approach across the European Union for both clinical trials and marketing authorisation applications under Directive 2001/83/EC. 

Why this matters for industry

MMPs are moving quickly from frontier science to real pipelines, but the concept paper explicitly recognizes a core bottleneck: today there is no tailored regulatory framework for non-clinical evaluation of MMPs, and existing guidelines were largely built for standard pharmaceuticals (including biologics) and ATMPs. According to EMA, this mismatch creates uncertainty for developers, inconsistencies in submissions and assessments, and can translate into development delays. 

For companies, the message is straightforward: regulators are preparing a more structured “playbook” for the non-clinical package, and early alignment will be a competitive advantage—especially for programs approaching first-in-human studies or pivotal clinical development.

What EMA includes (and excludes) under “microbiome-based medicinal products”

EMA frames MMPs as therapeutics originating from microbiomes (human, food-related and/or environmental) designed to treat or prevent disease by modulating the human microbiome. These products may consist of live or non-living microorganisms or their derivatives, with effects dependent on the strain(s) and site of administration—factors that add complexity to non-clinical development. 

The scope covers an illustrative set of product types, including Live Biotherapeutic Products, whole/highly complex ecosystem-based products, certain non-ATMP SoHO-derived medicinal products, and non-living MMPs (e.g., inanimate cells). 

Equally important is what is out of scope:

  • Human Microbiota Transplantation (as a procedure) under the SoHO Regulation (EU) 2024/1938
  • MMPs with genetically modified microorganisms classified as ATMPs
  • Food supplements and fermented-food cultures (not intended to prevent/treat disease)
  • Vaccines/standard immunological products not acting via microbiome modulation
  • Phage therapy/virome-based approaches, acknowledged as potentially relevant but likely for separate future work 

The key scientific/regulatory pain points EMA wants to tackle

The proposed reflection paper is meant to address aspects where conventional paradigms often break down for MMPs, notably: 

  1. Product diversity. From fixed compositions to tailored microbial consortia, with potentially different non-clinical strategies depending on the product type.
  2. Target diversity. MMPs may target any human-associated microbiome—gut, skin, oral, respiratory, urogenital, nasal, and beyond—so a one-size-fits-all approach is unlikely.
  3. Pharmacology models and dose selection. EMA highlights the limits of standard animal disease models, which may have poor relevance due to species-specific microbiome effects and limited translatability. The concept paper explicitly points to alternative models and New Approach Methodologies (NAMs) as potentially important. 
  4. Safety and biodistribution. Traditional toxicity approaches may not be appropriate. EMA calls out specific concerns that repeatedly surface for microbiome-based therapies:
    1. Biodistribution, including potential translocation
    2. Persistence
    3. Degradation/elimination pathways
    4. Potential shedding 

Timing and process: the consultation window is open now

The concept paper was adopted by CHMP for release for consultation on 16 February 2026, with a public consultation running from 2 March 2026 to 30 April 2026. EMA notes that comments received will be considered when preparing the draft reflection paper. 

The work will involve multiple EMA groups, including the Non-Clinical Working Party (NcWP) and others spanning quality, classification/borderline issues and clinical trial coordination. 

Expected impact (and what it signals to the market)

  • EMA anticipates that the reflection paper will:
  • Enhance regulatory clarity
  • Promote EU harmonization
  • Reduce unnecessary animal use in pharmacology/safety packages
  • Reduce uncertainty and delays
  • Support flexible, science-based approaches
  • Improve patient safety through more rigorous evaluation of novel MMPs 

For companies and investors, this is also a signal: EMA is treating MMPs as a strategic, fast-evolving class where regulatory science needs to catch up—an environment in which well-designed development packages and early regulator engagement can materially de-risk programs.

What companies should do now (practical takeaways)

  • Map your non-clinical package to the four focus areas EMA lists (product diversity, target diversity, models/NAMs, safety/biodistribution/shedding) and identify gaps early. 
  • Prepare to justify model relevance: if animal models are used, be ready to defend translatability; if NAMs are used, document validity and decision impact. 
  • Pressure-test your safety narrative around persistence, translocation and shedding—topics likely to become “standard questions” across dossiers. 
  • Engage in the consultation: EMA explicitly invites the pharmaceutical industry, academia, national authorities, EU agencies (ECDC, EDQM, EFSA), patient groups and healthcare professionals to contribute. Submitting comments is an opportunity to ensure the eventual reflection paper is workable for real-world development.