C2N Diagnostics

Healthtech · Diagnostics · Biotech

Milestone

FDA clears C2N's PrecivityAD2 blood test for adults as young as 40

Extending Alzheimer's testing below 65 matters because the disease's biology can start building 15-20 years before symptoms show.

• The FDA cleared C2N Diagnostics' PrecivityAD2 blood test to aid Alzheimer's diagnosis in symptomatic adults aged 40 and older, the youngest population yet covered by an FDA-cleared Alzheimer's blood test.
• C2N Diagnostics is a St. Louis startup spun out of Washington University School of Medicine in 2007, commercializing amyloid and tau blood biomarker technology co-invented by neurologists Randall Bateman and David Holtzman.
• The test uses high-resolution mass spectrometry rather than immunoassay methods, combining the Aβ42/40 ratio and %p-tau217 into an amyloid probability score to flag likely amyloid pathology.
• In a 1,142-subject validation study, PrecivityAD2 showed a 97.6% positive predictive value for ruling in Alzheimer's and a 93.1% negative predictive value for ruling it out, versus PET and CSF reference methods.
• An estimated 19-20 million U.S. adults 65 and older, plus hundreds of thousands aged 45-65, live with cognitive impairment that could benefit from earlier diagnosis.
• Alzheimer's Drug Discovery Foundation CEO Isobel Coleman noted that just over a year ago there were zero FDA-cleared Alzheimer's blood tests, and now there are three.
• Earlier, less invasive blood-based detection matters now that disease-slowing Alzheimer's drugs are on the market, since these treatments work better the sooner they start.
• The FDA-cleared version of PrecivityAD2 is expected to become available later in 2026, while the existing CLIA-validated lab version remains on the market in the meantime.