The US Food and Drug Administration may still take some oversight actions if a laboratory developed test (LDT) for COVID-19 is shown to be inaccurate or unsafe, an agency official implied at a virtual town hall for diagnostics test manufacturers.
The Department of Health and Human Services, the overseer of the FDA, announced last month that the agency would no longer conduct premarket reviews of all LDTs because the HHS Office of the Inspector General said the FDA lacked authority to regulate the tests. (Also see "FAQ Sheet From HHS Says FDA ‘Rarely Enforced’ Premarket Review Of LDTs" - Medtech Insight, 29 Aug, 2020.)
The FDA’s device center still has no specific comment on the 19 August policy statement from the HHS, said Toby Lowe, associate director for programs and performance in the agency’s Office of In Vitro Diagnostics and Radiological Health (OIR). But she indicated that in general, the agency may take some actions if a specific LDT raises concerns.
“When we are determining what to communicate about a specific test, we look at what the safety implications are and the public health implications,” Lowe said during the 2 September town hall. “And then we put out the information that’s available to be publicly distributed.” Such information may include safety announcements for health care providers, labs and patients as needed, she said.
But while officials were relatively closed-mouthed about the new LDT policy, they were willing to discuss a broad range of other issues of interest to the diagnostics community.
Template Development Continues
OIR director Tim Stenzel said the device center continues its work on submission templates for a range of innovative COVID-19 diagnostics, including serology tests using samples not collected in lab environments, serology home tests, and non-lab tests.
He noted that while the templates are a “good starting point,” they’re ultimately just recommendations, and reviewers remain open to alternative approaches when appropriate.
“If the sensitivity of a single test result is not high enough to make us comfortable authorizing it, that might be provided over the course of two self-tests if it’s the combined test that matters.” – Tim Stenzel
One such approach in which Stenzel expressed interest is what’s known as “serial testing protocol,” in which home-use tests are performed multiple times to increase the chance that an infection in an asymptomatic carrier will be detected. For example, a person might self-test on a Monday, and then repeat the test the following Wednesday. A positive result on either test indicates the person likely has the virus. This process makes it more likely that one of the test days will line up with when the virus is at its peak, Stenzel said.
“If the sensitivity of a single test result is not high enough to make us comfortable authorizing it, that might be provided over the course of two self-tests if it’s the combined test that matters,” he said.
And as it has been for some time, the possibility of saliva-based tests remained a topic of interest. The FDA has been in discussions with manufacturers about what it would take to get a saliva-based antigen test authorized, Stenzel said, adding that the developers “haven’t taken us up on that, and there may be good reason.”
He added that researchers are still learning how the COVID-19 virus sheds into saliva. Traditionally, respiratory viruses are more readily diagnosed through nasal swabs.
“For a variety of reasons, in this pandemic saliva has taken on an interesting and important role,” Stenzel said. “We’ve seen quite variable performance with saliva, and in some cases we haven’t been able to authorize the tests or have required more data.”
NCI Review Times Rise
Another recurrent concern during the town hall was a perceived lack of communication from FDA reviewers and other government bodies. Stenzel urged manufacturers that are unclear on where a premarket review stands to send an email to the templates email address for an update. And if there’s no response from a specific reviewer within 24 to 48 business hours, the concern can be escalated to the reviewer’s team lead as listed on the FDA’s website, he said.
Stenzel also noted an apparent upward trend in the average review time at the National Cancer Institute, which is evaluating and validating some COVID-19 tests authorized by the FDA under emergency use authorizations. The average wait time from receipt of an application to review results is 26 days, he said, while the time from receipt to public announcement that the test meets NCI standards is 58 days.
The town hall was the 24th in an ongoing weekly series, which is set to continue through at least 30 September. The next call will take place on 9 September at 12:15 EDT. (Also see "COVID-19: FDA Schedules 5 More Virtual Town Halls Through September" - Medtech Insight, 29 Aug, 2020.)