FDA Approves Novel Blood Test for Alzheimer’s Detection

On May 16, 2025, the US Food and Drug Administration (FDA) granted Breakthrough Device designation for the first in vitro blood testing device to help diagnose Alzheimer’s disease: the Lumipulse G pTau217/ß-Amyloid 1-42 Plasma Ratio by Fujirebio Diagnostics, Inc. The device detects amyloid plaques in adult patients aged 55 years or older who exhibit signs of the disease.

According to FDA Commissioner Martin A. Makary, MD, MPH, “Alzheimer’s disease impacts too many people, more than breast cancer and prostate cancer. Knowing that 10% of people aged 65 and older have Alzheimer’s, and that by 2050 that number is expected to double, I am hopeful that new medical products such as this one will help patients.”

The Lumipulse G pTau217/β-Amyloid 1-42 Plasma Ratio test analyzes two proteins, pTau217 and β-amyloid 1-42, which are found in human plasma, and calculates their ratio. This ratio is linked to the presence or absence of amyloid plaques in the brain, potentially reducing the need for PET scans.

Similar FDA-authorized or cleared tests, including one from the same manufacturer, rely on cerebrospinal fluid (CSF) obtained through a lumbar puncture, an invasive procedure known as a spinal tap. In contrast, the new Lumipulse test requires only a simple blood draw, making it significantly less invasive and more accessible for patients.

The FDA reviewed data from a clinical study involving 499 cognitively impaired adults to evaluate the Lumipulse G pTau217/β-Amyloid 1-42 Plasma Ratio test. The test results were compared with amyloid PET scans or CSF tests. The device showed 91.7% accuracy in identifying amyloid plaques in positive cases and 97.3% accuracy in confirming their absence in negative cases. Fewer than 20% of results were indeterminate.

These findings suggest the test can reliably detect amyloid pathology linked to Alzheimer’s in cognitively impaired patients, but results should be interpreted alongside other clinical information in specialized care settings.

Reference

US Food and Drug Administration. Published online May 16, 2025. https://www.fda.gov/news-events/press-announcements/fda-clears-first-blood-test-used-diagnosing-alzheimers-disease