FDA clears blood test to aid diagnostic test for Alzheimer’s Disease

The U.S. Food and Drug Administration (FDA) has cleared PrecivityAD2 for marketing, an innovative blood-based diagnostic test for Alzheimer’s disease

The drug was based on underlying technology developed at Washington University School of Medicine in St. Louis and commercialised by WashU startup C2N Diagnostics.

High-resolution mass spectrometry for amyloid detection

PrecivityAD2 is designed to identify the presence of brain amyloid plaques, a hallmark pathology of Alzheimer’s disease, in patients presenting with cognitive symptoms. Unlike other blood tests that use immunoassay methods, PrecivityAD2 utilises high-resolution mass spectrometry to provide precise quantitative measurements of key disease biomarkers.

The test calculates ratios of specific amyloid-beta proteins (Aβ42 and Aβ40) alongside two forms of tau protein (p-tau217 and total tau217).

Previous clinical validation studies showed that the test achieves over 90% accuracy in identifying amyloid pathology, performing comparably to traditional, more invasive diagnostic methods such as lumbar punctures (spinal taps) and positron emission tomography (PET) brain scans.

Improving diagnostic access and early intervention

Early and accurate diagnosis is increasingly critical following the approval of disease-modifying Alzheimer’s therapies that slow disease progression most effectively when administered during early clinical stages.

While physicians could previously order the test, formal FDA clearance provides several key advantages:

• Regulatory assurance:

  • Confirms the assay’s clinical performance and reliability across broad clinical settings.

• Expanded access:

  • Facilitates broader adoption by healthcare systems relying on FDA clearance for diagnostic quality assurance.

• Insurance coverage:

  • Expected to ease reimbursement pathways, lowering out-of-pocket costs and increasing patient access.

Academic innovation and commercial translation

The foundational technology stems from research co-led by WashU Medicine professors Randall J. Bateman, MD, and David M. Holtzman, MD. The researchers pioneered stable isotope-linked kinetics (SILK) to measure amyloid-beta dynamics, subsequently co-founding C2N Diagnostics in 2007 and licensing the patented technologies through the university’s Office of Technology Management.

C2N, which is expanding its operations in St. Louis’s Cortex Innovation District, validated and commercialised the technology into a newly cleared diagnostic test.