First Blood Test for Alzheimer's Disease Receives US Approval

In a significant advancement for Alzheimer's disease diagnosis, the United States has granted approval for the first blood test designed to detect this debilitating neurological condition. The test, developed by Fujirebio Diagnostics, assesses the ratio of two specific proteins present in the blood, which correlates with the presence of amyloid plaques in the brain--an indication of Alzheimer's disease. Traditionally, these plaques have only been identifiable through brain imaging or analysis of spinal fluid.

FDA Commissioner Marty Makary emphasized the impact of Alzheimer's, noting that it affects more individuals than breast and prostate cancers combined. Current estimates suggest that approximately 10% of individuals aged 65 and older are living with Alzheimer's, a figure expected to double by the year 2050. This new blood test is a hopeful prospect for early intervention with the recently approved treatments that aim to slow disease progression.

At present, there are two FDA-approved therapies for Alzheimer's: lecanemab and donanemab. These treatments target amyloid plaques and have demonstrated a modest effect in slowing cognitive decline, although they do not provide a cure. Proponents of these intravenous therapies, including many in the neurology field, advocate that initiating treatment earlier in the disease's progression can extend patients' independence for a few additional months.

Clinical evaluations of the blood test have shown that its results align closely with those obtained from positron emission tomography (PET) scans and spinal fluid analyses. Michelle Tarver, from the FDA's Center for Devices and Radiological Health, noted that the test's approval represents a pivotal step in making Alzheimer's diagnosis simpler and more accessible for patients in the United States, particularly in its early stages.

The blood test is approved for clinical use in patients who exhibit cognitive decline symptoms, with results needing to be interpreted alongside other clinical data. Alzheimer's disease is recognized as the most prevalent form of dementia, progressively diminishing individuals' memories and overall independence.