FDA greenlights Roche’s biomarker blood test for Alzheimer's

Roche has won US FDA clearance for a blood test that could move Alzheimer’s biomarker testing further into primary care, giving clinicians in the US a new way to assess amyloid pathology.

The Elecsys pTau217 assay, developed in partnership with Eli Lilly, has been greenlit for use with patients aged 55 and older who show signs of cognitive decline.

Through a simple blood test, Elecsys pTau217 detects phosphorylated tau 217 (pTau217), a biomarker commonly associated with the biological changes underlying Alzheimer’s disease, in a patient’s plasma. High levels of the biomarker indicate a greater likelihood that the patient may have Alzheimer’s disease, while lower levels can help clinicians rule out the disease without subjecting the individual to more invasive tests.

According to a release from Roche, it is the first FDA-cleared blood test using a single biomarker that can help both identify and rule out amyloid pathology.

It is designed to run on Roche’s existing cobas laboratory platforms, more than 4,500 of which are installed in US clinical laboratories, according to the company. It is not, however, a stand-alone diagnostic. Roche says results should be interpreted alongside other clinical information and diagnostic tools.

"Elecsys pTau217 has the potential to transform how Alzheimer's is assessed across primary and specialty care. This kind of innovation can help bring diagnostic evaluation closer to patients and give clinicians greater confidence in determining the right step in their care," said Dan Malarek, president and CEO of Roche, in a statement.

New diagnostic tools have been in high demand in Alzheimer’s research. As the most common cause of dementia, detecting Alzheimer’s-related brain changes early in the process is critical. Yet, an estimated 75% of people living with dementia remain undiagnosed worldwide, and the 25% who do receive a diagnosis face an average wait of 3.5 years after the appearance of cognitive decline.

Current detection methods, including positron emission tomography (PET) scan and cerebrospinal fluid (CSF) assessment, can be expensive and more invasive than a routine blood test. By offering a more accessible option, Roche aims to close the gap between symptoms and answers.

"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, MD, 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."