Blood-Based Alzheimer’s Test Gains CE Mark for Amyloid Pathology Detection

Alzheimer’s disease is the most common cause of dementia, yet confirmatory testing remains invasive and hard to access. Diagnosis currently takes an average of 3.5 years, and about 75% of people with dementia are undiagnosed. Confirmatory positron emission tomography scans and cerebrospinal fluid tests are costly and less accessible than a blood draw. A newly launched blood test now enables rule‑in and rule‑out assessment of amyloid pathology across care settings to support earlier evaluation.

Roche has announced that the company's Elecsys plasma phosphorylated‑tau 217 (pTau217) blood test has received the CE Mark. The single‑assay blood test measures phosphorylated tau 217, an indicator of amyloid pathology and a hallmark of Alzheimer’s disease. Standardized high and low cutoffs support consistent interpretation in both primary and secondary care settings.

Image: Roche’s CE-Marked Elecsys pTau217 blood test is a single‑assay blood test measures phosphorylated tau 217, an indicator of amyloid pathology and a hallmark of Alzheimer’s disease (image credit: Shutterstock)

A positive result indicates a high likelihood of amyloid pathology and can guide timely referral and specialist evaluation. A negative result indicates a low likelihood, helping clinicians rule out Alzheimer’s disease and avoid further invasive investigations such as cerebrospinal fluid collection or positron emission tomography. Indeterminate results require additional testing, and the assay should be used alongside other clinical information.

CE Marking was granted on data from retrospective studies in real‑world populations at the earliest symptomatic stages—subjective cognitive decline, mild cognitive impairment, and mild dementia. This aligns the test with use when individuals may notice memory changes but still live independently. Reported accuracy is comparable to spinal fluid diagnostics when assessed against positron emission tomography–computed tomography (PET‑CT), while the sample requirement is a routine blood draw.

The Elecsys pTau217 assay is described as clinically robust, supporting flexible workflows and sample handling consistent with routine laboratory processes. It is a high‑throughput, fully automated test that can be run across Roche’s installed base of instruments in countries accepting the CE Mark. These features aim to bring minimally invasive Alzheimer’s testing closer to patients and clinicians.

“The launch of pTau217 marks a significant step in providing a simple, blood-based tool to diagnose Alzheimer's much earlier in the patient journey,” said Matt Sause, CEO of Roche Diagnostics. “Today, many people face a long and difficult path to a diagnosis, often relying on specialised care and costly procedures. By bringing this advanced test into routine care, we are helping physicians to support patients and families with an earlier assessment that is critical for timely intervention, while reducing pressure on healthcare systems.”

“For millions of families navigating the uncertainty of Alzheimer’s, a timely diagnosis is the first and most critical step toward meaningful care. Lilly’s collaboration with Roche on the Elecsys pTau217 assay was driven by a shared commitment to bringing this innovation into routine practice, overcoming complexity in testing and enabling patients to make informed decisions about the future.” Carole Ho, M.D., Executive Vice President and President, Lilly Neuroscience, said.