Sources carry no Health Canada status, no Canadian availability, and no disclosed price
A blood test that helps identify the amyloid pathology associated with Alzheimer's disease has cleared the US Food and Drug Administration, opening the way for testing on more than 4,500 Roche cobas instruments already installed in US clinical laboratories.
Roche said in its announcement that the test is designed to integrate into existing laboratory workflows without requiring additional instrumentation.
The assay, Elecsys Phospho-Tau (217P) Plasma, covers individuals 55 years and older with signs, symptoms, or complaints of cognitive decline.
The company, which developed the test with Eli Lilly, describes it as the first and only FDA-cleared single-biomarker blood test supporting both rule-in and rule-out assessment of amyloid pathology using the same validated clinical cutoffs in primary and specialty care.
Results fall into positive, intermediate, and negative categories.
Reuters reported that the FDA clearance follows European approval for the test in May.
Labcorp and Quest Diagnostics have said they plan to offer the test through their laboratory networks, according to reporting by CNN, potentially widening availability across the United States.
Roche did not disclose the price.
An estimated 75 percent of people living with dementia remain undiagnosed, Roche said, citing published research, and those who are diagnosed often wait years for answers after symptoms appear.
Positron emission tomography imaging and cerebrospinal fluid testing, the traditional approaches to assessing amyloid pathology, may be costly, invasive, and difficult to access outside specialty centres.
Dan Malarek, president and CEO of Roche Diagnostics North America, said in the company's statement that Elecsys pTau217 is the first FDA-cleared single-biomarker blood test supporting both rule-in and rule-out assessment of amyloid pathology.
He said the test could bring diagnostic evaluation closer to patients and help clinicians determine the next step in care.
Carole Ho, executive vice president and president of Lilly Neuroscience, said in the same release that the collaboration aimed to bring one blood test into both primary care, “where most patients with cognitive complaints are first seen,” and specialty care.
Roche stated that the test is not intended for stand-alone use and that results should be interpreted alongside other diagnostic tools and clinical information.
The company also noted that the assay's safety and effectiveness have not been established for predicting the development of dementia or other neurologic conditions, or for monitoring the effect of therapeutic products.
Clinicians quoted by CNN raised questions about how the test performs in practice.
Richard Isaacson, director of research at the Institute for Neurodegenerative Diseases in Florida, said the test shares the challenges of other single Alzheimer's blood tests.
It rules out a diagnosis correctly, he told CNN in an email, but the "positive predictive value is not great."
He flagged false positives as a clinical problem, noting the test returns positive, negative, and indeterminate classifications.
Sample handling and conditions such as kidney disease or viral illness can also complicate interpretation, according to CNN's reporting.
Rachel Buckley, an associate professor of neurology at Harvard Medical School, told CNN by email that blood tests are not recommended for people without symptoms.
Until a disease-modifying therapy exists for asymptomatic individuals, she said, a physician would not change clinical guidance based on pTau217 levels alone in that group.
Fujirebio's Lumipulse became the first blood test cleared by the FDA to aid in the assessment of Alzheimer's disease in 2025, Reuters reported.
CNN reported that Roche and Lilly's Elecsys pTau181 test, which measures a different protein, received FDA clearance last year, and that the agency cleared C2N Diagnostics' PrecivityAD2 test last week.
All of the clearances described in the sources are US regulatory actions by the FDA.
None of the sources provided addresses Health Canada authorisation, Canadian laboratory availability, or coverage under Canadian public or private plans.
