FDA Regulatory Flexibility for Antimicrobials Analyzed

Harvard Medical School researchers say that manufacturers of investigational antimicrobial products frequently qualified for expedited testing and review programs offered by FDA. Writing in The Lancet Infection, the researchers say that since 2012 FDA has promulgated antimicrobial-specific guidance documents that reiterate the agency’s ongoing commitment to regulatory flexibility for this class of drugs.

The research examined all 1,065 new drugs and biologics approved by FDA between 1984 and 2018 and recorded each drug’s use of the Orphan Drug Act, fast-track, priority review, accelerated approval, and breakthrough therapy programs, with dates of INDs, NDAs, and new drug approval. It found that the flexible testing and review programs have been used at least as frequently for antimicrobial drugs as for non-antimicrobial drugs. Antimicrobials used most of FDA’s special expedited development or review programs with greater frequency than non-antimicrobials.

Antibacterials used all of the agency’s special programs with reduced frequency compared with other antimicrobial products.

Since the 1980s, the researchers say, antimicrobials, including antibacterials, experienced consistently shorter median development and review durations than non-antimicrobials.

“Frequent use of expedited regulatory development and review pathways for antimicrobial products was reflected in total development and approval times,” the researchers write, “suggesting that antimicrobial products that were approved have benefited from comparatively efficient development and approval pathways at FDA. We did not find evidence that antimicrobial development is more time-consuming than non-antimicrobial development or that regulators have been excessively rigid in their approach. Rather, clinical testing and review characteristics were similar for antimicrobials and non-antimicrobials.”