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A fourth Alzheimer's blood test simplifies the other three

Roche and Eli Lilly's Elecsys pTau217 was FDA-cleared August 24, 2026 — the fourth Alzheimer's amyloid blood test cleared in fifteen months. What makes it different isn't a new biomarker. It's the first cleared to do both rule-in and rule-out with the same cutoff, in a primary care office or a memory clinic alike.

The gist
Roche and Eli Lilly's Elecsys pTau217 was FDA-cleared August 24, 2026, for adults 55 and older with signs, symptoms or complaints of cognitive decline.
It's the fourth FDA-cleared Alzheimer's amyloid blood test, after Fujirebio's Lumipulse (May 2025), Roche's own Elecsys pTau181 (October 2025), and C2N's PrecivityAD2 (August 20, 2026).
The other three each need either a specialist setting, a rule-out-only read, or a different assay for a different question. pTau217 is the first cleared to do both rule-in and rule-out with one validated cutoff, usable in primary care or specialty care.
It runs on Roche's cobas analyzers already installed in over 4,500 US labs, and Labcorp and Quest have both said they'll offer it.

Count four now. Roche and Eli Lilly's Elecsys pTau217 cleared the FDA on August 24, 2026, four days after C2N's PrecivityAD2 and fifteen months after Fujirebio's Lumipulse became the first. Four cleared Alzheimer's amyloid blood tests now exist where there were zero before May 2025.

The biomarker isn't new. p-tau217 is already in a cleared test: Lumipulse measures it as half of a ratio against amyloid-beta. What Roche cleared is a single-biomarker version, read on its own, against one set of validated cutoffs.

One cutoff, either direction. Every prior cleared test picks a lane. Lumipulse's ratio is scoped to specialized care settings. Roche's own earlier test, Elecsys pTau181, was cleared as a rule-out only. PrecivityAD2 reached the youngest patients but is still its own separate read. pTau217 is the first cleared to support both ruling amyloid pathology in and ruling it out, using the same cutoff whether a primary care doctor orders it or a neurologist does.

Roche calls it the "Power of One." Dan Malarek, president of Roche Diagnostics North America, framed the clearance as "an important milestone in Alzheimer's disease diagnosis": one assay, one biomarker, one set of cutoffs, instead of a different tool for a different setting. Eli Lilly's Carole Ho put the stakes in patient terms: "For millions of families navigating the uncertainty of Alzheimer's disease, a timely diagnosis is the first and most critical step toward meaningful care."

Same symptom gate as the other three. pTau217 is cleared for adults 55 and older with signs, symptoms or complaints of cognitive decline, not for a symptom-free adult at a routine physical. That's the same limit every one of the four cleared tests shares. See the full rundown of all four tests for what symptoms qualify and where each one sits.

No new instrument required. Roche says the test runs on the more than 4,500 cobas analyzers already installed across US labs — no new hardware purchase to offer it. Labcorp and Quest Diagnostics have both said they plan to add it to their menus, which is how the prior three tests went from a single lab's clearance to broad availability within months.

Why this matters for you

Want the full picture of what's now available and what each test actually rules in or out? See all four FDA-cleared Alzheimer's blood tests, compared.

Disclaimer
This is commentary on published research, not medical advice. Talk to your doctor before changing anything based on a study.
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