FDA denies Lumos Diagnostics' bid for rapid test to differentiate between bacterial, viral infections

Lumos Diagnostics’ FebriDx point-of-care test will have to wait a bit longer to see the light of day in the U.S., as the Australian company announced (PDF) Monday that its 510(k) submission to the FDA has been rejected.

The rapid test analyzes fingerstick blood samples within 10 minutes to determine whether an acute respiratory infection is viral or bacterial. It runs on a hand-held, all-in-one device that captures and analyzes each blood sample.

With the news of the FDA's rejection of the test, Lumos' stock price plummeted. It opened Monday morning at 0.077 Australian cents, or just over five cents in U.S. currency, a drop of more than 50% from its last closing price. As the day went on, it only continued to slip, hitting a low point of 0.055 Australian cents.

FebriDx was developed with a dual aim of cutting down on unnecessary antibiotic prescriptions and, in doing so, potentially reducing the spread of antibiotic-resistant bacteria.

It works by looking for C-reactive protein and myxovirus resistance protein A (MxA) in each blood sample, representing bacterial and viral infections, respectively. One 2018 study of the test demonstrated positive predictive values of around 76% and a negative predictive value of 99%.

Though it can be used to screen for any acute respiratory infection, Lumos has directed much of its energy in recent months toward applying the diagnostic to COVID-19 cases. Another study published in 2020 found that FebriDx offered 93% sensitivity and 86% specificity when used specifically to test for the coronavirus.

The FDA denied Lumos’ application for clearance of the FebriDx test based on its potential for false negative results, the company said. The agency pointed out in its response that if the test overlooks the presence of MxA in a sample, it could lead to the continued spread of dangerous viral infections like COVID-19.

The rejection comes after the diagnostic was cleared by regulators in the U.K., Europe, Canada, the United Arab Emirates, Brazil and Australia.

Lumos said it plans to review its correspondence with and feedback from the FDA and explore its remaining options to push FebriDx through to a 510(k) clearance. Those routes could include filing a follow-up appeal with the agency or completely restarting the 510(k) submission process.

“Clearly this was not the outcome that the company was seeking, and this decision from the FDA is a significant disappointment for Lumos,” said CEO Doug Ward, who was appointed to the post just last month, following executive stints at Hologic, Personal Genome Diagnostics and more.

“The U.S. launch of FebriDx was a key component of Lumos’ future commercial plans,” Ward continued. “I will be actively working with our regulatory team and advisors to review this feedback and to develop a revised commercial plan for Lumos to incorporate this unexpected development.”