If you mention Alzheimer’s Disease (AD) to the average person, they will most likely think of the devastating symptoms of the disease, and the heartbreaking impact that the disease has on mostly elderly people and their families. However, pathologically AD happens years before any clinical symptoms become apparent.
The US FDA’s 2024 revised draft guidance, “Early Alzheimer’s Disease: Developing Drugs for Treatment Guidance for Industry” clearly identified the early, asymptomatic stages of AD.
Early Stages of Alzheimer’s Disease
Stage 1 Alzheimer’s Disease
Patients with characteristic pathophysiological changes of AD but no evidence of clinical impact.
Stage 2 Alzheimer’s Disease
Patients with characteristic pathophysiological changes of AD and subtle detectable abnormalities on sensitive neuropsychological measures or subjective complaints of mild cognitive symptoms but no functional impairment.
Stage 3 Alzheimer’s Disease
Patients with characteristic pathophysiological changes of AD, generally more apparent detectable abnormalities on sensitive neuropsychological measures, and mild but detectable functional impairment.
Early detection is critical for timely intervention. However, drug development to treat early stage patients very challenging because traditional clinical assessments often fail to identify AD at these stages, making it difficult to define early AD populations for clinical trials, monitor disease progression and determine efficacy of new treatments. To address these issues, FDA guidance highlights the importance of using biomarkers as surrogate endpoints in clinical trials for early AD.
Specifically, biomarkers such as amyloid-beta deposition, tau protein accumulation, and neurodegeneration, provide biological evidence of disease activity. For example, reductions in amyloid-beta or tau levels may serve as indicators of a drug’s potential to modify disease progression. By focusing on these biomarkers, pharmaceutical companies can design trials that are smaller, shorter, and more targeted, thus accelerating the drug development process.
RapidDx focuses on developing biomarker-based test methods, test kits and devices for the early detection of AD. The source of biomarkers in our tests is saliva. Saliva is a proven source of biomarkers indicating diseases and medical conditions. The collection of saliva is non-invasive and easy to perform, and the tests that we are developing will be easily accessed and cost effective. It is our goal to make mass screening for AD achievable.