A Blood Draw Could Replace Scans and Spinal Taps as the First Step in Alzheimer's Assessment

On 24 August 2026 the FDA cleared Roche's Elecsys pTau217, developed with Eli Lilly, the first single-biomarker blood test that can help both rule in and rule out Alzheimer's-related amyloid in primary and specialty care, for people 55 and over with memory symptoms.

Blood-based tests are making early assessment for Alzheimer's disease simpler and less invasive. Photo: National Eye Institute, via Wikimedia Commons (CC BY 2.0)

By the UISC BD Editorial Desk · United Information Service Center · Published 13 September 2026 · 5-minute read

For years, confirming the brain changes linked to Alzheimer's disease meant an expensive PET scan or a lumbar puncture. Blood tests are changing that, and the latest clearance makes the first step simpler for family doctors as well as specialists.

What Was Cleared

Test: Elecsys Phospho-Tau (217P) Plasma — known as Elecsys pTau217.
Maker: Roche, developed in collaboration with Eli Lilly.
FDA clearance: 24 August 2026.
Who it is for: people aged 55 and over with signs, symptoms or complaints of cognitive decline.

It is the fourth Alzheimer's blood test to gain FDA authorisation in less than two years.

What Makes It Different

Roche says Elecsys pTau217 is the first FDA-cleared single-biomarker blood test that supports both rule-in and rule-out assessment of amyloid pathology — the protein build-up associated with Alzheimer's — using the same clinical cut-offs in primary and specialty care.

Results fall into three categories: a positive, intermediate or negative likelihood of amyloid pathology.

Why It Matters

A simpler first step. The test can reduce the immediate need for PET imaging or a lumbar puncture during initial assessment.

Faster access. It runs on Roche's existing base of more than 4,500 cobas analysers in US laboratories, so labs do not need new equipment to offer it.

Earlier answers. Getting people to the right specialist sooner matters, because approved anti-amyloid treatments such as Leqembi and Kisunla are intended for early stages of the disease.

What It Cannot Do

It is not a screening test for healthy people. It is intended for people who already have symptoms of cognitive decline.

It does not diagnose Alzheimer's on its own. Results are interpreted by clinicians alongside memory assessments and other information.

An intermediate result may still need follow-up testing.

If You Are Worried About Memory

Talk to a doctor about specific changes you or family members have noticed.
Ask about the full assessment, not just a single test.
Keep up proven healthy habits — physical activity, managing blood pressure and staying socially and mentally active are consistently recommended for brain health.

More encouraging health research: a single-dose malaria treatment and new findings on the gut microbiome and healthy ageing.

Sources

"Roche receives FDA clearance for Elecsys pTau217, advancing Alzheimer's disease assessment across primary and specialty care," Roche — roche.com
"Alzheimer's Association statement on FDA clearance of Elecsys pTau217 blood test," Alzheimer's Association — alz.org
"FDA clears Roche's single-biomarker Elecsys pTau217 blood test for Alzheimer disease," NeurologyLive — neurologylive.com
"Around the nation: FDA approves another blood test for Alzheimer's," Advisory Board — advisory.com

amyloid blood test (1)

New Alzheimer's Blood Test Cleared by FDA: What Elecsys pTau217 Does