ST. LOUIS — C2N Diagnostics said the U.S. Food and Drug Administration has cleared its PrecivityAD2 blood test to help diagnose Alzheimer’s disease in adults aged 40 and older who have signs or symptoms of cognitive impairment.
The test is intended to be used alongside a standard clinical evaluation by health care professionals experienced in assessing cognitive decline. It is designed to identify patients with amyloid pathology associated with Alzheimer’s disease and is not intended to be used as a screening or stand-alone diagnostic test.
C2N said the FDA-cleared version of PrecivityAD2 is expected to become available later this year. The company’s current CLIA-validated version remains available through its clinical laboratory.
In a clinical validation study involving 1,142 people with signs or symptoms of cognitive decline, the test demonstrated a 97.6% positive predictive value for a positive result and a 93.1% negative predictive value for a negative result when compared with amyloid PET imaging or cerebrospinal fluid biomarker testing.
A “Likely Positive” result occurred in 17.3% of study participants and had a 77.3% positive predictive value, according to the company.
C2N said the test performed consistently across different stages of cognitive impairment, including patients with mild symptoms and those with more advanced cognitive concerns. It also showed reliable performance across increasing age and 12 chronic conditions commonly associated with aging, including diabetes, chronic kidney disease, coronary heart disease, depression, high blood pressure and obesity.
The company said PrecivityAD2 could provide patients with a more accessible alternative to PET scans or cerebrospinal fluid testing when clinicians are evaluating potential Alzheimer’s disease.
Many patients with cognitive impairment remain undiagnosed, particularly in the early stages of disease. C2N said earlier and more accurate diagnosis could help patients and clinicians make treatment and care decisions, including consideration of lifestyle changes and amyloid-targeting therapies.
PrecivityAD2 uses high-resolution mass spectrometry to measure multiple amyloid and tau protein biomarkers in blood. The test measures the Aβ42/40 ratio and the p-tau217/np-tau217 ratio, also known as %p-tau217.
Those measurements are combined using a proprietary algorithm to generate an Amyloid Probability Score 2, or APS2, ranging from zero to 100. The score is designed to indicate the likelihood that a patient has amyloid pathology associated with Alzheimer’s disease.
“The FDA clearance is a watershed moment for our company, the entire Alzheimer’s disease community, the field of molecular diagnostics, and precision medicine,” said Dr. Joel Braunstein, Co-Founder, CEO and President of C2N Diagnostics.
Braunstein said the company believes PrecivityAD2 could help simplify the diagnostic process for patients experiencing serious memory concerns and provide clinicians with additional information to guide care.
