Study: Test quickly identifies sepsis bacteria from whole blood, no culture necessary

May 20, 2019

T2 Biosystems, Inc., a developer of diagnostic products for critical unmet needs in healthcare, has announced the results of a trial it says demonstrated decisive evidence for the first direct-from-blood, non-culture test cleared by the Food and Drug Administration (FDA) for the diagnosis of bloodstream infections by multiple bacteria. The findings are published online in the Annals of Internal Medicine.

The company says the T2Bacteria Panel received FDA clearance in May 2018 and that is the first and only FDA-cleared test to identify sepsis-causing bacteria directly from whole blood without the wait for blood culture, which currently takes one to five or more days and is the current standard of care for diagnosing bloodstream infections (BSIs). The T2Bacteria Panel runs on the T2Dx Instrument and delivers results in three to five hours for the most common ESKAPE bacteria: Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa and Escherichia coli.

“There are well known limitations with relying solely on blood cultures. Technology that can deliver pathogen results in a matter of hours from initial blood draw, a capability which is unlike any other FDA-cleared device in the market today, can allow clinicians to approach initial clinical BSI treatment in a more informed way,” said M. Hong Nguyen, M.D., University of Pittsburgh Department of Medicine, and lead author of the study in a statement.

Key Study Findings:

The multi-center study enrolled and collected blood specimens from 1,427 patients who had a blood culture ordered as part of the standard of care. In the pivotal trial, the T2Bacteria Panel and T2Dx Instrument demonstrated:

·   Blood cultures took between 32 and 111 hours to identify pathogens whereas the T2Bacteria Panel took 3.6 to 7.7 hours to do so.

·    In 78 percent of probable or possible BSIs, subjects had blood culture-negative/T2Bacteria positive results despite treatment with active antibiotics.  

·    24 hours after blood draw, 20 percent of patients with blood culture-positive/T2bacteria-positive results were still not receiving effective therapy.

·    The T2Bacteria Panel had a 99.7 percent negative predictive value.

·    The T2Bacteria Panel had overall sensitivity of 89.7 percent per subject and per assay.

·    The T2Bacteria Panel had overall specificity of 89.5 percent per subject and 97.8 percent per assay.

“With a blood culture, it typically takes days to cultivate organisms to learn if a patient has bacteremia and, if so, what bacteria is causing the infection,” Hong said. “Additionally, blood cultures are not always sensitive enough to pick up the presence of bacteria in the bloodstream, such as when the patient has already been started on antibiotics. Timely administration of appropriate treatment might also help reduce hospital costs, such as by reducing length of stay, another added benefit to this technology.”

Dr. Sandy Estrada, vice president medical affairs of T2 Biosystems said in the statement, “Since the completion of this study in August 2017, we have secured FDA clearance and launched the T2Bacteria Panel in the U.S. and Europe. The initial commercial experience appears to be aligned with the strong results demonstrated in the pivotal study, as several customers have shared case studies of the T2Bacteria Panel providing actionable test results that improved patient care and several have developed and implemented patient selection criteria for the ICU, oncology units and the Emergency Department.”