Challenges for FDA Approval of Antimicrobial Susceptibility Tests

Romney Humphries, PhD, D(ABMM), section chief of Clinical Microbiology at the University of California, Los Angeles, discusses the challenges of receiving FDA approval on antimicrobial susceptibility tests.

Romney Humphries, PhD, D(ABMM), section chief of Clinical Microbiology at the University of California, Los Angeles, discusses the challenges of receiving US Food and Drug Administration (FDA) approval on antimicrobial susceptibility tests.

Interview Transcript (slightly modified for readability)

“One of the challenges as we look at these new technologies is the fact that in the United States, the gold standard for susceptibility testing is still this old method called broth microdilution, which was developed in the 1970s. You can imagine that as technology evolves we can become much more accurate at detecting resistance in a phenotypic way but you need to compare yourself to a much older and perhaps less well-performing system to get FDA approval from marketing of these tests in the United States; this is a big concern.

Another concern is the fact that the FDA has become much more stringent on which organisms a lab or a diagnostic manufacturer can test against certain antimicrobials. So unless this specific bug-drug combination is listed in the clinical indications of a drug label, the FDA does not grant approval for a test to test for that combination.

We know that people use antimicrobials off-label all the time and in some cases very frequently; a good example is the use of meropenem to treat Acinetobacter baumannii infections. That’s not actually a clinical indication in the meropenem drug label and so if you’re a new company trying to develop a new method, you would not be able to test that combination that’s being used every day.”