Source : Medtech Insight
People who test negative for COVID-19 using Abbott’s ID Now point-of-care test may need to confirm the result with a second test, a US Food and Drug Administration official said during a 20 May webinar.
The webinar was the ninth the FDA has hosted to update industry on the regulation and development of diagnostics for the novel coronavirus. Last week, the agency issued a public alert warning that the Abbott test posed a risk of false negatives. The test had been widely used because it can give results in fewer than 15 minutes. [MT126755]
Ongoing research suggests ID Now may not be sensitive enough to detect the virus in some patients with relatively low viral loads, Timothy Stenzel, director of the Office of In Vitro Diagnostics and Radiological Health within the FDA’s device center, said during the meeting. He added that the FDA continues to work with Abbott to update the test’s labeling to ensure safe use.
“What this means is, if there are clinical features or another indication that suggests that the negative results from an Abbot ID now test may not be a true negative, the agency recommends retesting with another molecular test for confirmation of that negative,” Stenzel said.
“As long as overall performance is good, saliva could be an adequate substrate to perform testing on.” – Timothy Stenzel He also discussed the FDA’s ongoing efforts to speed the development of saliva-based tests, calling the substance “an interesting sample type” because patients can collect it themselves relatively easily. Research has shown some variability in whether saliva samples yield the same results as other bodily fluids, but Stenzel said that didn’t necessarily mean saliva-based tests weren’t a good way to detect the virus.
“There is a potential variable that we don't yet understand, but as long as overall performance is good, saliva could be an adequate substrate to perform testing on,” he said.
In terms of future FDA clearance for COVID-19 diagnostics, Stenzel said the first direct antigen or molecular test aimed specifically at the virus would need to be granted de novo clearance. But after that, the agency is likely to release a special controls document that will allow subsequent tests to be cleared via the 510(k) pathway, he said, adding that he anticipates the special controls will be similar to those imposed for 510(k)s for tests for other respiratory viruses.
And in a sign of the progress some regions of the US have made in fighting the disease, one Washington State test developer said his lab has had a hard time finding patients who would test positive for COVID-19 to help validate a dry-swab sample collection kit. Stenzel replied that the FDA has been working on alternate ways for developers to get positive samples, though he declined to offer further details during the public call.
Finally, Stenzel said the FDA would be open to an over-the-counter COVID-19 test if researchers could demonstrate that lay users at home were able to get the same results as medical professionals. “Those are two levels of backgrounds and training. and therefore different levels of evidence are required to show accuracy,” he said.
The FDA plans to post a full transcript of the town hall in the next few weeks. The next call in the series is scheduled for 27 May.
By Elizabeth Orr