The U.S. Food and Drug Administration (FDA) has cleared the first blood test to aid in diagnosing Alzheimer’s disease, providing a less invasive alternative to costly PET scans and invasive spinal taps that could particularly benefit women, who represent nearly two-thirds of Alzheimer’s patients.
The Lumipulse G pTau217/ß-Amyloid 1-42 Plasma Ratio test detects amyloid plaques associated with Alzheimer’s disease in adult patients aged 55 and older exhibiting signs and symptoms of the disease. The test requires only a simple blood draw, making it significantly more accessible than previous diagnostic methods.
“Alzheimer’s disease impacts too many people, more than breast cancer and prostate cancer combined,” said FDA Commissioner Martin A. Makary, M.D., M.P.H. “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 test measures two proteins, pTau217 and β-amyloid 1-42, found in blood plasma and calculates their ratio, which correlates to the presence or absence of amyloid plaques in the brain. Previously, these plaques could only be detected through expensive PET scans that expose patients to radiation or through cerebrospinal fluid tests that require invasive lumbar punctures.
In clinical trials involving 499 plasma samples from cognitively impaired adults, the test demonstrated 91.7% accuracy in identifying individuals with amyloid plaques and 97.3% accuracy in confirming negative results when compared to PET scans or cerebrospinal fluid tests.
“Nearly 7 million Americans are living with Alzheimer’s disease and this number is projected to rise to nearly 13 million,” said Dr. Michelle Tarver, Director of the Center for Devices and Radiological Health. “Today’s clearance is an important step for Alzheimer’s disease diagnosis, making it easier and potentially more accessible for U.S. patients earlier in the disease.”
The blood test represents a significant advancement in accessibility, as it eliminates the need for specialized imaging facilities and can be performed in standard healthcare settings. However, the FDA notes that the test is not intended as a screening tool and must be interpreted alongside other clinical information.
The test was cleared through the FDA’s 510(k) pathway and received Breakthrough Device designation to expedite its development and review. Fujirebio Diagnostics, Inc. received the clearance for the test.
While the test is not a standalone diagnostic tool, the increased accessibility could lead to earlier detection and intervention, potentially improving outcomes for the millions of Americans living with Alzheimer’s disease.
