Infectious disease DNA tester Karius nets $100M to expand liquid biopsy reach

The infectious disease diagnostic developer Karius has secured another $100 million to help expand the reach of its microbial DNA test designed to detect more than 1,000 different pathogens from a single blood sample.

The Fierce Medtech Fierce 15 winner previously raised $165 million in February 2020, just before the coronavirus behind COVID-19 landed with full effect on U.S. shores. 

The Redwood City, California-based company said the latest funds will help move the Karius test outside of the hospital setting, where it’s currently being employed by about 400 locations and more than 6,000 physicians—largely at cancer centers, where patients can carry heightened risks to bacteria, fungi, parasites and viruses. Karius estimates that about 60% of deaths among people with cancer can be attributed to infections instead of the malignancy itself.

“Investing in Karius addresses critical gaps in healthcare diagnostics,” said Alex Morgan, partner at Khosla Ventures, which co-led the company’s series C round alongside 5AM Ventures and Gilde Healthcare.

“Traditional methods can be slow and can contribute to overuse of antibiotics, particularly risky for immunocompromised patients and fueling antimicrobial resistance,” added Morgan, who also joined Karius’ board of directors. “Precisely identifying pathogens allows for targeted treatment, minimizing the use of broad-spectrum antibiotics and reducing the risk of AMR proliferation.”

At the same time, the new proceeds will help support research to take Karius’ artificial intelligence-powered, cell-free DNA liquid biopsy approach into applications beyond infectious diseases.

“Every minute in the U.S., five cancer patients are admitted to the hospital due to infections—conditions that are often overshadowed by their primary diagnosis but are equally lethal, leading to nearly 1,000 deaths daily,” Karius CEO Alec Ford said in a statement. “This additional $100 million will significantly enhance our capacity to deliver rapid diagnostic testing to more patients, where faster treatment saves more lives and significant healthcare resources.”

The series C round also welcomed new investor Seventure Partners, plus returning backers among Softbank Vision Fund 2, General Catalyst, HBM Healthcare Investments, Blue Water Life Sciences, Innovation Endeavors, Waycross Ventures and others, the company said. Gilde General Partner Joep Muijrers and 5AM Ventures advisor Andrew Booth also took seats on Karius’ board.

“Karius’ strong revenue and growth illustrates how impactful the Karius Test is to clinical care. We are proud to co-lead the company’s series C as Karius expands into new markets and moves to profitability,” said Booth.

Last fall, the company put forward a study showing its approach could improve diagnoses and help guide the treatment of patients with blood cancers who developed cases of pneumonia.

“Pneumonia commonly complicates hematopoietic cell transplantation and treatment of hematologic malignancies, yet current diagnostic standards identify a causative pathogen in less than half of our patients undergoing bronchoscopy and extensive noninvasive testing,” the study’s principal investigator, Stephen Bergin, an assistant professor of medicine at the Duke University School of Medicine, said at the time.

The Karius blood test was able to identify the probable cause of pneumonia in 12% of patients after all standard efforts had failed, including traditionally hard-to-spot pathogens. The study, published in March in the journal Clinical Infectious Diseases, also found that among those patients, antimicrobial therapies could have been optimized in 81% of cases.

“This well-designed clinical trial conducted at leading academic centers shows that the Karius Test is highly valuable in immunocompromised patients with suspected infection,” said Ned Sharpless, former director of the National Cancer Institute and once acting commissioner of the FDA, who joined Karius’ board in August 2023. “The ability to identify the causal pathogen with true urgency is critical in this patient population, and more rapid diagnosis through use of the Karius Test will reduce suffering and death in these vulnerable patients.”