FDA clears Roche and Lilly's Elecsys pTau217 blood test for Alzheimer's

What the FDA cleared

The clearance covers people 55 and older with signs, symptoms or complaints of cognitive decline, Roche said in its 24 August announcement. The Elecsys pTau217 test measures phosphorylated tau 217 alone, rather than pairing it with amyloid-beta in a ratio as Fujirebio's Lumipulse does. Roche says results must be read alongside other clinical information and are not a standalone diagnosis.

The test runs on Roche's Cobas laboratory analyzers, which are already installed at more than 4,500 clinical laboratories across the US, according to the American Journal of Managed Care. Roche said no new instruments are needed. Labcorp and Quest Diagnostics have said they plan to offer the test through their laboratory networks, CNN reported.

The American Journal of Managed Care describes Elecsys pTau217 as the first and only single-biomarker blood test for assessing amyloid pathology to rule in or rule out Alzheimer's disease in adults 55 and older. In that group, the test showed high agreement with amyloid PET imaging. European approval came in May, Roche said.

Why a blood test changes the pathway

An estimated 75% of people living with dementia remain undiagnosed, according to the American Journal of Managed Care. Confirming amyloid today means a PET scan or a lumbar puncture, and both are costly and hard to reach for many patients. Roche calls the single-marker approach, run against one set of validated cutoffs, "the Power of One".

Jared R. Brosch, a neurologist at Indiana University Health, said in a press release that the test could help clinicians evaluate more patients earlier in the disease course. Dan Malarek, president and CEO of Roche Diagnostics North America, said it could bring diagnostic evaluation closer to patients.

About 7 million people in the US have Alzheimer's disease, according to the Mayo Clinic. The two FDA-approved drugs, Leqembi and Kisunla, aim to slow, not cure, the disease, NBC reported. Carole Ho, president of Lilly Neuroscience, said in a press release that a timely diagnosis is the first and most critical step toward meaningful care.

Four clearances in fifteen months

Fujirebio's Lumipulse was the first blood test cleared by the FDA to aid Alzheimer's assessment, on 16 May 2025, according to the University of Wisconsin School of Medicine and Public Health. Roche and Lilly's Elecsys pTau181, which measures a different protein than the newly cleared test, followed later in 2025, CNN reported. C2N Diagnostics' Precivity AD2 was cleared the week before the pTau217 decision.

Between May 2025 and August 2026 the agency cleared four blood tests to help doctors evaluate Alzheimer's in people with cognitive symptoms, Being Patient reported. At least 25 blood tests are commercially available worldwide, according to the Alzheimer's Association. "Each FDA clearance gives clinicians another validated option to work with," Maria C. Carrillo, chief science officer at the Alzheimer's Association, said in a statement in August 2026.

The accuracy caveat

Richard Isaacson, director of research at the Institute for Neurodegenerative Diseases in Florida, told CNN the test has "sufficient negative predictive value" but that its positive predictive value "is not great". "False positive tests are a problem in clinical practice," he said, adding that sample handling and conditions such as kidney problems or viral illness can confuse interpretation.

Rachel Buckley, an associate professor of neurology at Harvard Medical School, told CNN that blood tests are not recommended in people without symptoms, because a doctor would not change clinical guidance based on pTau217 levels alone in that group.

Isaacson compared the test to cholesterol. "Just like when a doctor orders a cholesterol test, do they ever order only 1 test? No, they order a panel of tests," he told CNN, advocating the same strategy here. The FDA noted in one of its recent blood-test approvals that inaccurate results, false positives and false negatives included, "could lead to an inappropriate diagnosis of, and unnecessary treatment for, Alzheimer's disease".

Coverage and price

Roche did not disclose the test's price, CNN reported. Insurance coverage for Alzheimer's blood tests is still variable, Being Patient reported. Medical Daily reported that Medicare does not cover the tests for pre-symptom screening and that the Alzheimer's Smart and Accelerated Prioritization Act, which would allow coverage before symptoms are severe, is pending in Congress. The outlet also cited an ALZRA estimate of $500 to $1,000 in anticipated out-of-pocket cost, significantly less than a PET scan, which can cost several thousand dollars.