FDA Clears Roche Blood Test for Alzheimer’s Amyloid Pathology Assessment
Posted on 24 Aug 2026
An estimated 75% of people living with dementia remain undiagnosed, while confirmatory tools such as positron emission tomography (PET) or cerebrospinal fluid (CSF) testing can be costly, invasive, and difficult to access outside specialty centers. Clinicians need scalable, minimally invasive approaches to evaluate adults with cognitive complaints. A newly FDA-cleared blood test offers a single-biomarker option that supports both rule-in and rule-out assessment of amyloid pathology using the same validated cutoffs across care settings.
Elecsys pTau217 (Elecsys Phospho-Tau [217P] Plasma) was developed by Roche Diagnostics in collaboration with Eli Lilly and Company and is a blood-based assay designed to aid in identifying amyloid pathology associated with Alzheimer’s disease in individuals aged 55 years and older who have signs, symptoms, or complaints of cognitive decline. On August 24, 2026, the U.S. Food and Drug Administration (FDA) cleared the test for use across both primary and specialty care settings. The assay provides results as positive, intermediate, or negative and is intended to be interpreted alongside clinical information and other relevant diagnostic findings.
As a single-assay solution centered on one biomarker, Elecsys pTau217 is designed to provide a consistent approach to amyloid assessment across care settings. It is not intended as a stand-alone test, and its safety and effectiveness have not been established for predicting dementia or other neurologic conditions or monitoring therapeutic effects. The assay can be implemented on more than 4,500 installed cobas laboratory instruments in the United States, allowing laboratories to integrate testing into existing workflows without additional instrumentation. The same validated clinical cutoffs are applied in both primary and specialty care.
In evaluations of adults aged 55 years and older with cognitive decline associated with Alzheimer’s disease, Elecsys pTau217 demonstrated high agreement with amyloid PET imaging, providing a minimally invasive option for assessing amyloid pathology. By supporting both rule-in and rule-out determinations with a single biomarker, the blood test may help clinicians identify patients who warrant further testing or specialist referral and determine when additional evaluation, including PET imaging or cerebrospinal fluid (CSF) testing, may be appropriate.
“For decades, clinicians have faced significant challenges in accurately diagnosing Alzheimer’s disease in its early stages. While PET imaging and cerebrospinal fluid biomarkers can confirm amyloid pathology in patients with cognitive impairment, these approaches may be costly, invasive and not readily accessible for many patients,” said Jared R. Brosch, M.D., Neurologist, Indiana University Health.
"Advances in blood-based biomarkers have the potential to transform the diagnostic pathway by expanding access to evaluation for Alzheimer's across a variety of care settings. As these tools become available, clinicians may be able to evaluate more patients earlier in the disease course, improving diagnostic confidence and helping patients and their families make more informed decisions at a critical time," said Dr. Brosch.
