New single biomarker blood test gets FDA clearance

• On August 24, 2026, the U.S. FDA cleared a brand new single-biomarker blood check to assist docs detect indicators of Alzheimer’s illness.
• The check helps docs decide each rule-in (constructive outcome) and rule-out (unfavourable outcome) evaluation of amyloid pathology, a trademark of Alzheimer’s illness.
• The blood check is particularly for older adults 55 and older with indicators or signs of cognitive decline.

Known as the Elecsys® Phospho-Tau (217P) Plasma (pTau217) blood check, the check was developed in collaboration by pharmaceutical corporations Roche and Eli Lilly and Firm.

Medical Information Immediately spoke with 4 Alzheimer’s illness consultants to seek out out extra in regards to the Elecsys pTau217 blood check — the way it works, the way it’s totally different from the exams already used in the present day for diagnosing Alzheimer’s illness, how individuals will be capable to take the check, and the way they predict this new check will change the Alzheimer’s illness diagnostic panorama.

In accordance with Peter Gliebus, MD, chief of neurology and director of cognitive and behavioral neurology at Marcus Neuroscience Institute, part of Baptist Well being South Florida, the Elecsys pTau217 blood check works by detecting phosphorylated tau 217 in blood, one of many earliest and most particular blood indicators of Alzheimer’s.

“It rises early within the illness and stays largely regular in different neurodegenerative circumstances,” Gliebus defined. “Though it’s a tau marker, blood pTau217 intently correlates with brain amyloid.”

Laura Nisenbaum, PhD, interim chief science officer of the Alzheimer’s Drug Discovery Basis (ADDF), stated the Elecsys check measures pTau217 focus in plasma and makes use of validated cutoffs to categorize outcomes as constructive, intermediate, or unfavourable.

“One among its distinguishing options is that it applies the identical cutoffs throughout each major and specialty care settings, which issues enormously for constant, scalable implementation,” Nisenbaum instructed MNT.

The Elecsys pTau217 blood check will not be the primary Alzheimer’s check to be authorized by the FDA.

“The FDA cleared the Lumipulse G pTau217/β-amyloid 1-42 Plasma Ratio [test] in Might 2025,” Dung Trinh, MD, an internist for MemorialCare Medical Group and chief medical officer of Wholesome Mind Clinic in Irvine, CA, instructed MNT. “That check measures two biomarkers and calculates a ratio. Roche additionally obtained FDA clearance in 2025 for its Elecsys pTau181 check, which is primarily meant to assist rule out Alzheimer’s-related amyloid pathology in major care.”

Trinh defined that what distinguishes the brand new Elecsys pTau217 check is that it’s a single-biomarker assay that Roche says helps each rule-in (constructive outcome) and rule-out (unfavourable outcome) evaluation of amyloid pathology, utilizing the identical validated cutoffs in major and specialty care.

“That simplicity may very well be operationally vital as a result of one assay can probably be used all through the affected person journey somewhat than requiring totally different testing methods in several settings,” he continued.

MNT additionally spoke with Megan Glenn, PsyD, medical neuropsychologist on the Middle for Reminiscence and Wholesome Growing old on the Hackensack Meridian Neuroscience Institute at Jersey Shore College Medical Middle in New Jersey, who stated that whereas we’ve seen a number of different blood markers explored over the previous few years, a lot of them seize common mind irritation or are simply affected by different neurological circumstances.

“What makes this particular tau marker stand out is its robust connection to the precise amyloid plaques which can be attribute of Alzheimer’s illness,” Glenn defined.

“Compared on to different choices, this marker has persistently confirmed to be essentially the most correct at figuring out these organic adjustments. It provides us a a lot clearer image of what’s taking place biologically than earlier blood exams might provide. This stage of reliability is strictly what we have to confidently use blood testing in a medical setting.”
— Megan Glenn, PsyD

“As a result of it’s designed to run on Roche’s present labs, it ought to be accessible by way of most of the similar laboratories that deal with routine blood work,” she stated. “In observe, a affected person experiencing cognitive signs would talk about testing choices with their doctor, who would order it as a part of a broader analysis.”

“The outcome, categorized as constructive, intermediate, or unfavourable for amyloid pathology, would then be interpreted alongside different medical data to information subsequent steps. It isn’t a check sufferers can order themselves, and a constructive outcome ought to all the time immediate additional dialog with a clinician about what it means and what comes subsequent.”
— Laura Nisenbaum, PhD

Trinh added that the FDA-cleared meant inhabitants is vital to notice for this check.

“That is for people aged 55 and older who’re presenting with indicators, signs, or complaints of cognitive decline,” he stated. “It isn’t at the moment cleared as a common screening check for wholesome, asymptomatic adults.”

Glenn stated that the FDA clearance of this new blood check is a large step ahead in making cognitive evaluations extra accessible for everybody.

“By utilizing customary laboratory gear, it brings superior testing capabilities to a a lot wider group of sufferers who may by no means have had entry to specialised mind scans,” she defined. “A very powerful factor to recollect is that this check helps a cautious medical analysis and doesn’t change a complete evaluation by a certified skilled.”

“This marks a major inflection level, not simply small information: it’s the first FDA-cleared blood check that may each verify and exclude Alzheimer’s amyloid pathology from a single blood pattern, out there on lab devices already in hundreds of hospitals,” Gliebus stated.

“Simply over a yr in the past, there have been no FDA-cleared blood exams for Alzheimer’s — now there are 4,” Nisenbaum commented. “That could be a outstanding shift in a really brief interval.”

“The broader implication is that blood-based diagnostics are not a future promise. They’re changing into a part of routine medical observe, and that adjustments how we take into consideration the whole lot downstream, from trial design to drug growth to how sufferers and households get solutions. The diagnostic panorama 5 years from now will look very totally different from the one we had only a yr in the past.”
— Laura Nisenbaum, PhD

Earlier than incorporating the Elecsys pTau217 blood check into routine care, Trinh stated there are a number of issues he would need to very clearly perceive. For instance, he would need to see the entire FDA labeling and real-world efficiency information, not solely total accuracy, however the constructive and unfavourable predictive values within the forms of sufferers he truly sees.

“Predictive worth can change considerably relying on the prevalence of illness within the inhabitants being examined,” he defined. “Second, I’d need to know extra in regards to the intermediate outcome group. A check can carry out very nicely total, however from a clinician’s perspective, the essential operational query is: What number of sufferers fall into the grey zone, and precisely what ought to we do with them?”

Trinh stated he would additionally need clinicians and readers to know precisely what the check can not inform us.

“Roche particularly states that it isn’t a stand-alone diagnostic check, and its security and effectiveness haven’t been established for predicting who will later develop dementia or for monitoring remedy response,” he defined.

“A biomarker can inform us one thing crucial about Alzheimer’s-related pathology, however caring for the affected person nonetheless requires figuring out whether or not that pathology explains the signs, what stage of illness the individual is in, what different circumstances could also be contributing, and what remedy or care plan is acceptable.”
— Dung Trinh, MD