As part of its overall strategy for addressing antimicrobial resistance risks associated with the use of antimicrobial drugs in animals, the U.S. Food & Drug Administration announced Oct. 9 a potential revised process and criteria for ranking antimicrobial drugs based on their importance in human medicine.

FDA said it "is committed to ensuring that this ranking process be based on current and sound science, given the role that the ranking of antimicrobials plays in guiding FDA’s activities related to managing antimicrobial resistance risks associated with antimicrobial use in animals."

To describe these potential revisions in detail, FDA has published a concept paper and issued a request for comments in the Federal Register to obtain early public feedback on the content of the paper. FDA also plans to hold a virtual public meeting to present the details and receive additional comments.

The concept paper outlines a potential approach for updating the current list of antimicrobial drugs ranked by their importance in human medicine — commonly referred to as “Appendix A” of FDA’s Guidance for Industry (GFI) 152 — to take into account improved understanding of antimicrobial resistance and other changes since the ranked list was established in 2003, including changes in available treatment options, changes in human clinical practices and other scientific advancements.

GFI 152, “Evaluating the Safety of Antimicrobial New Animal Drugs with Regard to Their Microbiological Effects on Bacteria of Human Health Concerns,” is used to support the animal drug approval process and provides a recommended risk assessment methodology for evaluating and mitigating antimicrobial resistance concerns associated with the use of antimicrobial drugs in food-producing animals, the agency explained.

While the original ranking criteria in GFI 152 emphasized the treatment of foodborne infections in humans, the potential revised criteria in the concept paper more broadly consider the importance of these drugs in human medicine, based on availability of treatment options and seriousness of human illness, FDA said. These revised criteria are intended to better characterize the overall importance of a drug for treating human infections, whether or not they are foodborne.

However, in addition to this importance ranking, FDA said it would consider other risk factors as part of an overall assessment of antimicrobial resistance risks associated with the use of an antimicrobial drug in animals.

FDA said the current list of antimicrobial drug medical importance rankings in Appendix A will continue to be used to support the animal drug evaluation and risk assessment process while the potential revised criteria and rankings detailed in the concept paper are under consideration.

If the revised ranking list described in the concept paper were to be adopted by FDA, through guidance, it would replace the list currently included as Appendix A to GFI 152. The revised list would be used to inform the recommended risk assessment methodology provided in GFI 152 and also could be utilized as a risk management tool for informing other FDA initiatives related to the judicious use of medically important antimicrobials in veterinary medicine, the agency said.

The concept paper is a means to facilitate public comment on one potential approach to revising antimicrobial drug human medical importance rankings and is not intended to be construed as recommendations or guidance. FDA said it intends to consider all comments received on the concept paper that are submitted in a timely manner before issuing draft guidance for additional public comment.

The virtual public meeting to discuss this potential revised approach will be held on Nov. 16, 2020. For additional information about this meeting, including registration and specific questions on which FDA would like to receive comments, visit: FDA Public Meeting on Potential Approach for Ranking of Antimicrobial Drugs According to Their Importance in Human Medicine: A Risk Management Tool for Antimicrobial Animal Drugs.

FDA is accepting public comment on the concept paper Oct. 9, 2020, through Jan. 15, 2021. To electronically submit comments to the docket, visit www.regulations.gov, and type FDA-2020-N-1736 in the search box.