FDA clears two tests used to assist treatment decisions for infections, sepsis
The FDA recently approved the expanded use of the Vidas Brahms PCT Assay, which guides antibiotic treatment decisions for patients with lower respiratory tract infections and sepsis, and authorized the marketing of the PhenoTest BC Kit, which is the first test of its kind to identify organisms that cause bloodstream infections and determine their susceptibility to antibiotics.
The new indications for the Vidas Brahms PCT Assay (bioMérieux Inc.) allow health care providers in hospitals and EDs to determine whether an antibiotic should be started or stopped in patients with lower respiratory tract infections, and stopped in patients with sepsis. It is the first test to use procalcitonin (PCT), a biomarker indicating the body’s response to bacterial infections.
The Vidas Brahms PCT Assay was first approved by the FDA to help clinicians predict disease severity and the risk for mortality caused by sepsis. The FDA’s decision to expand its use is based on published results of prospective, randomized clinical trials that compared PCT–guided therapy with standard therapy. The data showed a significant reduction in antibiotic use and similar safety outcomes among patients receiving PCT–guided therapy vs. those receiving standard therapy. The FDA warned, however, that health care providers should not rely solely on the test results because they are intended to be interpreted in the context of clinical status and other laboratory results.
“Unnecessary antibiotic use may contribute to the rise in antibiotic-resistant infections. This test may help clinicians make antibiotic treatment decisions,” Alberto Gutierrez, PhD, director of the Office of In Vitro Diagnostics and Radiological Health at the FDA’s Center for Devices and Radiological Health, said about the PCT assay in a news release.
In addition to authorizing the expanded use of the Vidas Brahms PCT Assay, the FDA is now allowing the marketing of the PhenoTest BC Kit (Accelerate Diagnostics Inc.) — the first to both identify pathogens that cause bloodstream infections and determine which antibiotics the pathogens will likely respond to.
Although traditional identification and antibiotic susceptibility tests take up to 24 to 48 hours to produce results, the PhenoTest BC Kit, performed on the Pheno System, can identify bacteria or yeast in approximately 1.5 hours and provides information on antibiotic susceptibility in certain pathogens within approximately 6.5 hours.
“By identifying organisms and knowing earlier which antibiotics the organism is likely to respond to, health care professionals can treat patients with bloodstream infections more appropriately,” Gutierrez said in a release.
The test can detect 14 species of bacteria and two species of yeast that cause bloodstream infections. It also provides antibiotic sensitivity information on 18 selected antibiotics for a subset of detected organisms and can identify the presence of two indications of resistance.
The marketing approval is based largely on a review of 1,850 positive blood cultures in which the PhenoTest BC Kit exceeded FDA requirements for identification and antimicrobial susceptibility testing, according to a press release from the manufacturer. The trial involved more than 39,000 tests across 13 trial sites. Results showed that the PhenoTest BC Kit performed with an overall sensitivity of 97.4% and a specificity of 99.3% for identification. Compared with standard broth microdilution, the overall essential and categorical agreement for susceptibility was 96.3% and 96.4%, respectively, the release said.
Disclosure: Gutierrez reports no relevant financial disclosures.