Overview
- The U.S. Food and Drug Administration has granted marketing clearance for PrecivityAD2, a blood test developed by C2N Diagnostics to help identify brain amyloid in symptomatic adults.
- PrecivityAD2 uses high‑resolution mass spectrometry to quantify the Aβ42/Aβ40 ratio and phosphorylated tau217 alongside total tau217 from a single blood draw.
- Independent validation studies reported the assay detects amyloid pathology with more than 90% accuracy versus PET scans and cerebrospinal fluid benchmarks.
- Clinicians and advocates say FDA clearance should make health systems more willing to use the test, help discussions with payers about coverage, and cut time and cost for trial screening while noting the test must be interpreted with clinical assessment.
- The test traces to Washington University research on amyloid kinetics and was commercialized by C2N, which plans a formal commercial launch later in 2026 and is expanding operations in St. Louis’s Cortex Innovation District.