FDA Approves First Blood Test to Aid in Alzheimer’s Diagnosis

The U.S. Food and Drug Administration has cleared the first blood-based diagnostic test designed to aid in detecting Alzheimer’s disease, potentially reshaping the diagnostic process for millions of Americans. The test, known as the Lumipulse G pTau217/ß-Amyloid 1-42 Plasma Ratio, provides a less invasive alternative to traditional methods and is expected to make early diagnosis more accessible to patients exhibiting symptoms of the condition.

Designed for individuals aged 55 and older who show signs of cognitive decline, the test measures the levels of two specific proteins in the blood—pTau217 and β-amyloid 1-42—to calculate a ratio that indicates the likely presence of amyloid plaques in the brain, a hallmark of Alzheimer’s disease. Previously, amyloid plaques could only be reliably confirmed through expensive PET scans or cerebrospinal fluid tests, the latter requiring an invasive spinal tap. This new test only requires a blood sample, allowing for broader, more practical use in clinical settings.

Alzheimer’s disease currently affects nearly 7 million Americans, with that number projected to rise to nearly 13 million by 2050. The disease progressively impairs memory and basic cognitive function, and early detection is critical for managing its progression. By offering a simpler diagnostic method, the new test could lead to earlier and more accurate interventions for patients experiencing cognitive decline.

The FDA reviewed the Lumipulse blood test through the 510(k) premarket notification pathway, determining it to be substantially equivalent to a previously authorized cerebrospinal fluid-based test. Data from a clinical study involving 499 participants showed the test’s strong predictive accuracy: over 91% of positive results aligned with amyloid presence confirmed through PET scans or spinal fluid analysis, while over 97% of negative results were similarly consistent. Only a small fraction of results were indeterminate.

The test is intended for use in specialized care settings and must be interpreted alongside other clinical findings. Potential risks include the chance of false positives, which could lead to unnecessary treatment and patient distress, or false negatives, which might delay appropriate care. It is not approved as a stand-alone diagnostic or general screening tool.

Fujirebio Diagnostics, Inc. received FDA clearance for the test, which also received Breakthrough Device designation, a program that accelerates the review of devices addressing critical health needs.

Article by multiple RFHC contributors, based upon information from a press release issued by the U.S. Food and Drug Administration.

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