(Source-KTVZ)
With another expensive Alzheimer’s treatment anticipated to receive approval soon, the nonprofit Alzheimer’s Association has released the final version of its new diagnostic creep criteria for the disease. For the first time, the criteria advise doctors to use biomarkers—such as beta amyloid and tau proteins detected by lab tests or brain scans—rather than traditional pen-and-paper memory and cognitive tests.
Biomarker-Based Diagnosis
The authors of the new criteria argue that this change aims to detect Alzheimer’s in its earliest, most treatable stages, even before symptoms appear. This means that individuals could potentially be diagnosed with Alzheimer’s based on a blood test alone, without any evident memory issues. The authors maintain that biology, rather than symptoms, should be the basis for diagnosis, as the absence of symptoms does not preclude future development.
However, these criteria have drawn criticism from some experts and drug industry watchdogs. Critics point out that individuals can have beta amyloid proteins in their brains and blood without ever developing dementia symptoms. Additionally, there is no substantial evidence that administering expensive and risky medications before symptoms appear will benefit patients in the long run.
Risks and Benefits of Early Diagnosis
The new drugs—antibodies targeting beta amyloid to remove it from the brain—have shown modest benefits in clinical trials. Beta amyloid peptides form sticky plaques in the brain, and tau proteins create tangles that disrupt nerve cell communication, both considered hallmarks of Alzheimer’s disease. However, there is still debate about whether beta amyloid plaques are a cause or consequence of the disease.
In an 18-month study of individuals in the early stages of Alzheimer’s, the antibody lecanemab, approved by the FDA in 2023, slowed cognitive decline by 27% compared to a placebo. Similarly, the experimental drug donanemab slowed disease progression by about 35% compared to a placebo. Despite these benefits, the drugs carry risks, such as brain swelling and microbleeds, potentially leading to hospitalization.
Critics argue that the new criteria could significantly increase the number of people eligible for these new drugs, generating substantial profits for pharmaceutical companies. Dr. Adriane Fugh-Berman, director of PharmedOut at Georgetown University, criticized the guidelines for potentially labeling healthy individuals as having Alzheimer’s, which could cause unnecessary distress and benefit pharmaceutical companies.
Defending the Criteria
The Alzheimer’s Association asserts that the new criteria are based on the latest scientific developments. While current Alzheimer’s therapies are not approved for asymptomatic individuals, the association recommends against diagnostic creep testing in people without cognitive impairment. Dr. Maria C. Carrillo, the Alzheimer’s Association’s chief science officer, emphasized that the goal is to advance diagnosis, treatment, and prevention to improve individual care and reduce the societal impact of Alzheimer’s.
The working group that developed the criteria included members with financial ties to companies marketing or developing Alzheimer’s drugs. This has raised concerns about potential conflicts of interest influencing the guidelines. Dr. Eric Widera, a geriatrician at the University of California, San Francisco, criticized the guidelines for potentially expanding the market for Alzheimer’s drugs by broadening the diagnostic creep criteria.
Diagnostic Creep Future Guidelines
The Alzheimer’s Association plans to convene a new working group to develop detailed diagnostic creep guidelines for clinicians. These new guidelines are expected to be highly specific and may include recommendations for specific commercial products. The association aims to publish these new clinical guidelines by 2025.
While the new criteria aim to advance Alzheimer’s diagnosis and treatment, they have sparked controversy regarding their potential to expand the patient population and benefit pharmaceutical companies. As new guidelines are developed, it will be crucial to consider both the benefits and risks of early diagnosis and treatment to ensure the best outcomes for patients.
