EMA Framework for the Qualification of Non-Mutagenic Impurities
The European Medicines Agency (EMA) has adopted a Reflection Paper on the Qualification of Non-Mutagenic Impurities (EMA/CHMP/4299/2026), introducing a new scientific framework for the safety assessment of non-mutagenic impurities in medicinal products. This document establishes harmonized principles to support proportionate, risk-based regulatory decision-making.
Why is it relevant?
Although the ICH Q3A and Q3B guidelines establish reporting and qualification thresholds, there was a regulatory gap when new impurities appeared or their levels increased after marketing authorization. This document provides updated criteria and promotes more scientific and proportionate approaches.
Main takeaways
Addresses regulatory gaps
Complements ICH Q3A and Q3B by providing guidance when new impurities emerge, or levels increase post-authorization.
Risk-based qualification
Introduces a structured, tiered assessment approach based on toxicological relevance.
Animal testing reduction
Prioritizes alternative methods in line with the 3Rs principles.
Acceptable Level (AL)
Establishes AL derivation from toxicological data (e.g. NOAEL, BMDL) with defined adjustment factors.
Strategic assessment tools
- Read-across with analogous compounds
- Threshold of Toxicological Concern (TTC)
- In silico methods ((Q)SAR, modelling)
- In vitro tests and New Approach Methodologies (NAMs)
Qualification criteria clarified
- Impurities that are relevant metabolites in non-clinical or clinical studies
- Impurities structurally related to the API without new toxicophores
Limited in vivo testing
New animal studies should be exceptional and preferably conducted with the isolated impurity.
Who is affected?
- Marketing Authorization Holders managing post-approval changes
- Sponsors developing new medicinal products
- Quality, CMC, and toxicology teams involved in impurity control strategies
What MAHs should do now
1. Review impurity strategies against the new EMA qualification framework.
2. Implement integrated risk assessments combining toxicology, structure, and exposure data.
3. Prepare robust justifications for AL, TTC, and read-across approaches.
4. Strengthen NAM capabilities to support non-animal testing strategies.
5. Anticipate regulatory expectations for post-approval changes and development programs.
How we can support
We support companies in aligning impurity qualification programs with the new EMA framework through:
- Integrated risk assessments
- Regulatory justification packages
- Acceptable Level calculations and TTC application
- Read-across strategies and NAM implementation
If you are managing post-authorization changes or emerging impurities in development, early alignment with this framework will be critical.
