Guidance on Genotoxic Impurities Sets Levels for Experimental Drugs

Different thresholds for genotoxic and carcinogenic impurities will be set for drugs in clinical development based on the length of time they will be administered to patients in trials, according to an FDA draft guidance.

The draft applies to drugs for which a specific safety signal suggests the potential for increased carcinogenic risk as well as for NDA or BLA supplements that request substantial changes in product labeling, such as a new indication or dosing regimen, the FDA says.

The ability to identify and control drug-related impurities during early developmental stages is limited because of issues related to scale and maturity of production processes. “Taking all these considerations into account, higher daily levels of exposure to potentially genotoxic impurities may be acceptable during the clinical development of the drug product compared to what is appropriate for a marketed drug product,” the FDA says in the guidance.
Drug GMP Report