FDA Clears Blood Test to Detect Alzheimer's in Primary and Specialty Care

On Monday, the FDA approved the Elecsys pTau217 blood test for identifying amyloid-beta pathology linked to Alzheimer's disease in individuals aged 55 and older with cognitive decline symptoms, according to Roche. Developed in collaboration with Eli Lilly, the test offers both rule-in and rule-out capabilities using consistent clinical cutoffs in both primary and specialty care settings.

Lilly's partnership with Roche aimed to integrate one blood test into both primary, where most patients with cognitive concerns initially seek help, and specialty care, according to Carole Ho, MD, president of Lilly Neuroscience.

The assay targets plasma phosphorylated tau 217, a marker of amyloid burden, simplifying laboratory testing through a single biomarker and validated clinical cutoffs. Evaluated in individuals 55 and older with cognitive decline signs, symptoms, or complaints, Elecsys pTau217 showed high agreement with amyloid PET imaging, the company reported. However, Elecsys pTau217 is not intended as a standalone diagnostic tool; results must be considered alongside other diagnostic tests and clinical information, Roche emphasized.

Roche cautioned that the safety and effectiveness of the assay have not been established for predicting dementia development or other neurologic conditions or for monitoring therapeutic product effects. The FDA clearance announcement follows the FDA's approval of the PrecivityAD2 blood test from C2N Diagnostics, which employs mass spectrometry to quantify amyloid and tau peptides for Alzheimer's diagnosis in symptomatic individuals.

In 2025, the FDA also approved Fujirebio's Lumipulse test for identifying Alzheimer's in symptomatic patients and Roche's Elecsys pTau181 assay for ruling out Alzheimer's in primary care settings.

Lab-developed tests unapproved by the FDA are currently available on the market. The Alzheimer's Association released guidance in 2024 outlining sensitivity and specificity parameters for blood tests to either triage or diagnose individuals with cognitive impairment. Both LabCorp and Quest Diagnostics announced Monday that they would offer the Elecsys pTau217 test through their networks.