Fresh after securing $100m in financing earlier this month, Karius has a regulatory win after the US Food and Drug Administration (FDA) granted breakthrough device designation to its DNA-based blood test for lung infections in immunocompromised patients.

The genomic diagnostic company’s device, the Karius Test, has been commercially available in the US since 2017 under the Clinical Laboratory Improvement Amendments of 1988 (CLIA) – a pathway for laboratory-developed tests (LDTs).

The liquid biopsy-based test detects microbial DNA circulating in the blood and then uses AI to analyse the sample for more than 1,000 pathogens.

Karius’ chief medical officer Brad Perkins said the company is pursuing FDA marketing authorisation because “improved diagnostic tests are urgently needed for [immunocompromised patients]”.

Breakthrough device designations by the FDA place sponsors in line for prioritised review for the device’s submission, along with enhanced interactions with FDA experts to discuss feedback during the premarket review phase.

The FDA approval is for the diagnosis and management of immunocompromised patients with suspected lung infections such as pneumonia.

Karius provided evidence via data from the PICKUP clinical study, which demonstrated a 40% relative increase in the identification of probable pneumonia cause when the test was added to standard-of-care.

Karius board member and former director of the National Cancer Institute Norman E Sharpless said: “Recent data from several trials indicate that the Karius Test offers a speedy, accurate, and sensitive diagnosis of infectious causes of pneumonia and related infections in immunocompromised patients.”

Pneumonia causes more than a million hospitalisations in the US each year, according to the American Lung Association.

Karius closed a $100m Series C financing round earlier this month. The company said it will use the funds to expand the number of US hospitals currently using its test, which currently stands at 400.

The liquid biopsy market is predicted to reach $6.8bn by 2028 with a compound annual growth rate of 20.9%, according to analysis by GlobalData.

On April 29, the FDA issued its Final Rule in officially making explicit that in vitro diagnostic products (IVD), also known as LDTs, are medical devices under the Federal Food, Drug, and Cosmetic Act.