First Light Diagnostics, Chelmsford, Mass., announced that the FDA has cleared the company’s SensiTox C. difficileToxin Test along with its proprietary MultiPath Analyzer to be marketed in the United States.

C.difficile causes more life-threatening hospital infections than any other pathogen and is considered by the CDC to be an urgent antibiotic resistance threat. Each year, approximately 250,000 C. difficile infections and 12,500 deaths cost the U.S. healthcare system about $1 billion. Currently, both nucleic acid amplification tests and enzyme immunoassays are used to diagnose C. difficile infections. Nucleic acid amplification tests are very sensitive but lack specificity. Enzyme immunoassays, designed to detect toxins produced by C. difficile, are specific but cannot detect low levels of toxin. Because of these limitations, neither test method alone is accurate for the diagnosis of C. difficile infection. First Light aims to improve diagnosis of C. difficile by commercializing an accurate test that is both sensitive and specific.

The SensiTox C. difficile Toxin Test uses the company’s proprietary MultiPath technology for single molecule counting to ultrasensitively detect toxins and biomarkers at much lower levels than most rapid tests on the market, according to First Light Diagnostics. The SensiTox C. difficile Toxin Test aligns with the current clinical guidance for the diagnosis of C. difficile infection that recommends use of toxin tests that very sensitively detect toxin levels. First Light’s test, which detects C. difficile toxins A and B, was evaluated in a clinical study conducted at three sites in the U.S. that included more than 1,000 specimens. In this study, the test was shown to have excellent clinical sensitivity and specificity. The test delivers a result in 35 minutes on the MultiPath Analyzer, a fully automated benchtop system with high throughput and continuous random access loading of specimens.

“We are very pleased with the results of the clinical study and are convinced our test has enormous clinical value in the diagnosis and rapid treatment of C. difficile infection,” says Joanne Spadoro, president and chief executive officer of First Light Diagnostics. “This is an important first step toward our goal of improving patient outcomes by empowering clinicians with more accurate and rapid test results.”In addition to its SensiTox C. difficile Toxin Test, First Light is developing a portfolio of products for the rapid generation of antimicrobial susceptibility test (AST) results, enabling clinicians to prescribe the optimal targeted, narrow-spectrum therapy in hours instead of the days it currently takes. The first test under development is the UTI-Direct test that rapidly detects urinary tract infections, identifies pathogens, and determines optimal antibiotic treatment.

Featured image: Medical illustration of Clostridioides difficile bacteria, formerly known as Clostridium difficile, from the CDC publication Antibiotic Resistance Threats in the United States, 2019. Medical Illustrator Jennifer Oosthuizen, courtesy CDC.