New Alzheimer's Blood Diagnostics
FDA Clears New Blood Tests to Aid Alzheimer's Disease Diagnosis for Adults
Key Points
PrecivityAD2 is the first FDA-approved blood test for adults 40 and older undergoing evaluation for cognitive decline; it is not a screening test for the general population and must be interpreted with a medical examination, history, and additional tests.
The test uses high-resolution mass spectrometry to measure multiple forms of amyloid beta and tau proteins and outputs a 0-to-100 score indicating the likelihood of brain amyloid deposits, with a study of 1,142 participants showing 97.6% of positive results aligned with brain amyloid and 93.1% of negative results aligned to absence of deposits.
Roche and Eli Lilly's Elecsys pTau217 is FDA-cleared as the first single-biomarker blood test to support both rule-in and rule-out assessments of amyloid pathology across primary and specialty care settings.
The Elecsys pTau217 has European approval as of May, ahead of its U.S. clearance, illustrating cross-market regulatory acceptance for this biomarker-based test.
The test can be deployed across Roche's U.S. lab network (more than 4,500 analyzers) with Labcorp and Quest Diagnostics planning to offer it through their networks to broaden access.
The FDA has cleared multiple blood tests to help diagnose Alzheimer's disease, marking a major shift toward simpler, faster screening. MassDevice reported that Roche and Eli Lilly's Elecsys pTau217 test was approved for adults 55 and older showing signs of cognitive decline. The test detects a protein called phosphorylated tau 217, a biomarker linked to Alzheimer's brain damage. Archynetys noted this is the first single-biomarker blood test approved for both ruling in and ruling out Alzheimer's disease across primary and specialty care settings.
Two New Blood Tests Expand Diagnostic Options
Beyond the Roche-Lilly test, the FDA also cleared PrecivityAD2 for adults 40 and older being evaluated for cognitive decline. This test uses high-resolution mass spectrometry to measure multiple forms of amyloid beta and tau proteins. It produces a score from 0 to 100 showing how likely brain amyloid deposits are present. In a study of 1,142 people, 97.6% of positive results matched actual brain amyloid, and 93.1% of negative results showed no amyloid deposits.
Blood Tests Can Now Reach Millions Through Lab Networks
Roche and Eli Lilly's breakthrough is the ability to run these tests on existing lab machines. MarketScreener reported that Roche has more than 4,500 analyzers already installed across U.S. laboratories. Labcorp and Quest Diagnostics—the two largest lab testing companies—plan to offer the Elecsys pTau217 test through their networks. This means millions of Americans can access the test without needing specialized equipment or travel to research centers.
Why Blood Tests Matter More Than Brain Imaging
Until now, doctors had to use PET scans or collect cerebrospinal fluid to check for Alzheimer's markers. These methods are expensive, invasive, and not widely available. Blood tests are cheaper, faster, and less invasive. MarketScreener emphasized that these approvals reflect a push toward simpler diagnostic pathways. Blood tests can now complement—or even replace—imaging tests in many clinical settings, making early detection possible for more patients.
Important Limits: These Are Not Screening Tests for Everyone
A critical distinction: PrecivityAD2 and the Elecsys tests are not general screening tools for healthy people. They are designed for adults already showing signs of memory problems or cognitive decline. Archynetys noted that test results must be interpreted alongside medical examinations, patient history, and additional clinical information. A positive blood test alone does not diagnose Alzheimer's—it indicates amyloid pathology that requires further evaluation by a doctor.
Sentiment
Mostly PositivePublishers
17
Articles
77
Reach
94
