ICH M7 Guideline entering implementation period (Step 5)

The purpose of this new ICH Guideline is to offer guidance on analysis of structure activity relationships (SAR) for genotoxicity. It is also intended to resolve highly complex questions such as whether impurities with similar alerts that potentially have similar mechanism of action should not be combined in calculating a Threshold of Toxicological Concern (TTC) and whether the TTC may differ based on differences in the approved duration of use.
The document is applicable for new drug substances and new drug products during their clinical development and subsequent applications for marketing. Due to the complexity of the guideline, implementation of M7 in the respective national rules and regulationsis not expected prior to 18 months after ICH publication.However, there are some exceptions like: For conducting the Ames test, the specifications of M7 need to be applied immediately.