FDA Clears PrecivityAD2 Blood Test to Aid Alzheimer Disease Diagnosis
KEY TAKEAWAYS
- The FDA cleared PrecivityAD2, a blood-based test intended to help identify amyloid pathology associated with Alzheimer disease.
- The test is indicated for adults aged 40 years and older with signs or symptoms of cognitive impairment who are undergoing evaluation for Alzheimer disease or other cognitive decline.
- PrecivityAD2 is intended for use with clinical assessment and is not a screening or stand-alone diagnostic test.
The Food and Drug Administration (FDA) cleared PrecivityAD2 (C2N Diagnostics, St. Louis, MO), a blood-based in vitro diagnostic test designed to aid evaluation of amyloid pathology associated with Alzheimer disease (AD).
The test is indicated for adults aged 40 years and older who present with signs or symptoms of cognitive impairment and are undergoing evaluation for AD or other causes of cognitive decline. According to a statement from C2N Diagnostics, the FDA-cleared version of PrecivityAD2 is expected to become available later this year, while the company’s current CLIA-validated test remains available through its clinical laboratory.
Clearance Highlights
- PrecivityAD2 is intended to be ordered by health care professionals experienced in evaluating cognitive impairment.
- The test uses high-resolution mass spectrometry to measure plasma beta-amyloid and tau peptide isoforms.
- Results are expressed through the Aβ42/40 ratio and p-tau217/np-tau217 ratio, which are combined into the amyloid probability score 2.
- In a clinical validation study of 1142 people with signs or symptoms of cognitive decline:
- A Positive result had a 97.6% positive predictive value for detecting brain amyloid plaques.
- A Negative result had a 93.1% negative predictive value based on amyloid PET visual read or cerebrospinal fluid biomarker testing as reference methods.
- A Likely Positive result occurred in 17.3% of participants and had a 77.3% positive predictive value.
C2N Diagnostics reported that PrecivityAD2 showed performance across the range of cognitive impairment evaluated in the clinical study, including individuals with mild symptoms and those with more advanced cognitive concerns. The company also stated that test performance was consistent with increasing age and across 12 prespecified chronic disease categories commonly associated with aging.
PrecivityAD2 is intended to support, not replace, clinical evaluation. The test is not cleared for population screening or as an independent diagnostic test for Alzheimer disease.
Source
C2N Diagnostics. FDA clears C2N Diagnostics’ PrecivityAD2—first Alzheimer’s blood test for adults with cognitive symptoms as young as 40. BioSpace. Published August 20, 2026. Accessed August 21, 2026. https://www.biospace.com/press-releases/fda-clears-c2n-diagnostics-precivityad2-first-alzheimers-blood-test-for-adults-with-cognitive-symptoms-as-young-as-40