Roche and Eli Lilly Advance Alzheimer’s Diagnosis With FDA-Cleared pTau217 Blood Test

A new blood-based biomarker test could help make Alzheimer’s disease assessment more accessible, less invasive and easier to integrate into routine care.

Roche and Eli Lilly have reached a significant milestone in Alzheimer’s disease diagnostics, with the U.S. Food and Drug Administration (FDA) clearing Roche’s Elecsys® Phospho-Tau (217P) Plasma (pTau217) blood test.

Developed through the companies’ ongoing diagnostic collaboration, the test measures phosphorylated tau 217 (pTau217), a biomarker associated with amyloid pathology and Alzheimer’s disease. Its clearance marks another step toward shifting Alzheimer’s assessment away from diagnostic pathways that can depend heavily on more complex and invasive testing.

A new approach to Alzheimer’s assessment

The Elecsys pTau217 test is intended for adults aged 55 and older who present with signs, symptoms or complaints of cognitive decline associated with Alzheimer’s disease.

One of its key differentiators is its ability to support both rule-in and rule-out assessment of amyloid pathology using the same validated clinical cutoffs. This makes it the first FDA-cleared single-biomarker blood test designed for this dual assessment across both primary and specialty care settings.

A positive result indicates a high likelihood of amyloid pathology, while a low result can help indicate that amyloid pathology is unlikely. The test is intended to be used alongside other clinical information as part of the diagnostic assessment.

Why blood-based biomarkers matter

Diagnosing Alzheimer’s disease can be a complex and lengthy process. Traditionally, clinicians have relied on tools such as positron emission tomography (PET) imaging and cerebrospinal fluid (CSF) analysis to identify amyloid pathology.

While these approaches can provide valuable information, they can also be costly, less accessible and, in the case of CSF testing, invasive.

A blood-based biomarker therefore has the potential to make the diagnostic pathway more convenient and scalable. Roche says the pTau217 test can be used across primary and specialty care, potentially allowing more patients to be assessed earlier in their care journey.

The test itself provides results through a routine blood sample and is designed for use on Roche’s cobas® e 402 and e 801 analytical systems.

Building on an expanding diagnostic collaboration

The FDA clearance of pTau217 builds on the work Roche and Lilly have already carried out in Alzheimer’s diagnostics.

In 2025, Roche’s Elecsys pTau181 test received FDA clearance as a blood-based tool to aid in the initial assessment of Alzheimer’s disease and other causes of cognitive decline in people aged 55 and older. That test was designed primarily to help rule out Alzheimer’s-related amyloid pathology.

The new pTau217 assay expands the companies’ diagnostic portfolio by providing a single-biomarker approach capable of supporting both rule-in and rule-out assessment.

The test also received a CE Mark in Europe in May 2026, where Roche described it as the first blood test for Alzheimer’s disease pathology with a single-assay design intended to support both assessment pathways across primary and secondary care.

What this could mean for the future of Alzheimer’s care

The importance of developments such as pTau217 extends beyond the diagnostic test itself.

Earlier and more accessible identification of Alzheimer’s pathology could help clinicians determine appropriate next steps sooner, while also supporting better-informed conversations with patients and their families. As disease-modifying therapies and other interventions continue to develop, the ability to identify eligible patients efficiently becomes increasingly important.

Blood-based biomarkers could therefore become an increasingly important part of the broader Alzheimer’s care pathway — complementing existing diagnostic technologies rather than necessarily replacing them.

For the biopharma and life sciences industry, this development also highlights a broader trend: diagnostics are becoming increasingly central to how innovative therapies are identified, accessed and delivered.

As biomarker technologies continue to advance, the integration of diagnostics, clinical decision-making and treatment pathways will remain an important area to watch across the healthcare ecosystem.