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 (optimistic consequence) and rule-out (adverse consequence) evaluation of amyloid pathology, an indicator 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 At the moment spoke with 4 Alzheimer’s illness consultants to seek out out extra concerning the Elecsys pTau217 blood check — the way it works, the way it’s completely different from the checks already used in the present day for diagnosing Alzheimer’s illness, how folks will have the ability 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 principally regular in different neurodegenerative circumstances,” Gliebus defined. “Though it’s a tau marker, blood pTau217 carefully 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 optimistic, intermediate, or adverse.

“Certainly one of 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 advised MNT.

The Elecsys pTau217 blood check shouldn’t be the primary Alzheimer’s check to be permitted 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, advised 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 supposed 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 (optimistic consequence) and rule-out (adverse consequence) evaluation of amyloid pathology, utilizing the identical validated cutoffs in major and specialty care.

“That simplicity could possibly be operationally essential as a result of one assay can doubtlessly be used all through the affected person journey slightly than requiring completely different testing methods in several settings,” he continued.

MNT additionally spoke with Megan Glenn, PsyD, scientific neuropsychologist on the Heart for Reminiscence and Wholesome Getting older on the Hackensack Meridian Neuroscience Institute at Jersey Shore College Medical Heart in New Jersey, who stated that whereas we have now seen a number of different blood markers explored over the previous couple of years, lots of them seize normal mind irritation or are simply affected by different neurological circumstances.

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

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

“As a result of it’s designed to run on Roche’s current labs, it needs to be accessible by way of lots 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 consequence, categorized as optimistic, intermediate, or adverse for amyloid pathology, would then be interpreted alongside different scientific data to information subsequent steps. It isn’t a check sufferers can order themselves, and a optimistic consequence ought to at all times immediate additional dialog with a clinician about what it means and what comes subsequent.”
— Laura Nisenbaum, PhD

Trinh added that the FDA-cleared supposed inhabitants is essential 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 presently cleared as a normal 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.

“Through the use of normal laboratory tools, 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. “Crucial factor to recollect is that this check helps a cautious scientific analysis and doesn’t change a complete evaluation by a certified skilled.”

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

“Simply over a 12 months in the past, there have been no FDA-cleared blood checks for Alzheimer’s — now there are 4,” Nisenbaum commented. “That could be a outstanding shift in a really quick interval.”

“The broader implication is that blood-based diagnostics are not a future promise. They’re turning into a part of routine scientific observe, and that adjustments how we take into consideration all the pieces downstream, from trial design to drug growth to how sufferers and households get solutions. The diagnostic panorama 5 years from now will look very completely different from the one we had only a 12 months 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 knowledge, not solely total accuracy, however the optimistic and adverse predictive values within the varieties 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 might need to know extra concerning the intermediate consequence group. A check can carry out very effectively total, however from a clinician’s perspective, the vital 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’t inform us.

“Roche particularly states that it’s not 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