The FDA reported a new streamlined pathway for diagnostic testing as part of a serial testing program using pooled samples, a pathway that should enable the further reopening of the economy. However, the FDA’s Tim Stenzel said April 21 that this new pathway relied on accumulated data for molecular testing, and that the agency lacks sufficient data to provide a similar mechanism for this use of antigen tests.
The FDA is becoming more amenable to screening and surveillance tests for the COVID-19 pandemic, although the distinction between test uses is not always clear. Toby Lowe, the associate director of the Office of In Vitro Diagnostics and Radiological Health (OIR), said on the agency’s weekly town hall that the difference between surveillance and screening tests is whether the individuals who are screened can act on the information thus derived.
Diagnostic manufacturers are turning their attention to antibodies for those who have been vaccinated for the SARS-CoV-2 virus, and the U.S. FDA’s Tim Stenzel had some advice about this on the Feb. 10 testing town hall. Stenzel advised that developers think of such tests in the same vein as a companion diagnostic (CDx) in that these antibody test will have to be separately validated for each vaccine that is included in the test’s labeled claims.
The U.S. FDA is still struggling to keep up with the volume of diagnostic emergency use authorizations (EUAs), but it is not for want of effort. Tim Stenzel, director of the FDA’s Office of In Vitro Diagnostics and Radiological Health (OIR), said on the Feb. 3 testing town hall that the agency is processing nine such applications per day, a big jump over the rate of one per day in the early weeks of the COVID-19 pandemic.
The SARS-CoV-2 virus has now had ample time to mutate, as reports of the proliferation of multiple variants make clear, and the U.S. FDA’s Tim Stenzel said the agency is now focused on three variants, including one recently reported from Israel. Stenzel said on the latest COVID-19 testing town hall that one of the key concerns regarding existing authorized tests is the potential for loss of sensitivity, a problem the agency hopes to overcome without the use of live virus.
Reports of multiple new variants of the SARS-CoV-2 virus have emerged, raising questions about the efficacy of vaccines, but also regarding the utility of diagnostic and other tests. The U.S. FDA’s Tim Stenzel said single-target tests are thus at a greater risk of returning a false negative result, adding that these developers “should consider this carefully” in surveillance of their tests.
The U.S. FDA is actively working on guidance for conversion of emergency use authorizations (EUAs) to conventional premarket review programs, but the FDA’s Tim Stenzel said he does “not perceive a need to rush to convert EUAs” because of the volume of EUA applications, and because he does not expect the public health emergency “to end anytime soon.”
The U.S. FDA’s stated policy is that it will not review emergency use authorizations (EUAs) for lab-developed tests (LDTs) for the COVID-19 pandemic, but that doesn’t mean labs are completely shut out. The FDA’s Toby Lowe said that a lab that wants to pair an assay that already has an EUA with a new software installation on lab instrumentation can work with the assay developer to update that EUA.
The U.S. FDA’s device center has declared it will not review emergency use authorization (EUA) requests for lab-developed tests (LDTs) for the COVID-19 pandemic, but on the agency’s most recent town hall, on Oct. 14, FDA officials were uncertain as to whether labs should file those EUAs, leaving labs in a state of limbo yet again.
The diagnostic industry in the U.S. and elsewhere has scrambled to keep up with the COVID-19 pandemic, and one of the key developments will be a test that can be used at home without medical supervision. However, Tim Stenzel, director of the U.S. FDA’s Office of In Vitro Diagnostics and Radiological Health, said on the Sept. 16 diagnostic town hall that the agency is keen on authorizing such a test, but has yet to receive any emergency use authorization filings. “We want to see a home test submission, and we’re willing to be very flexible here,” Stenzel said.
