Five Small Molecule Compounds Targeting Aβ in Alzheimer’s Disease

Alzheimer’s disease (AD) is a complex neurodegenerative disorder characterized by cognitive decline, with amyloidbeta ($A \beta$) accumulation playing a central role in its pathogenesis. Despite numerous efforts in drug development, effective treatments targeting $A \beta$ have faced significant challenges, including inadequate target engagement, poor clinical efficacy, and toxicity concerns. This review explores the relationship between $A \beta$ and AD pathogenesis, discussing the amyloid cascade hypothesis and the hypothesis of $A \beta$ oligomer pathogenicity. In addition, five representative drugs targeted for $A \beta$ are summarized, highlighting their mechanisms of action, preclinical and clinical data, and the challenges faced in development. We also address the need for multitarget approaches, early intervention, and improved drug delivery methods, such as overcoming the bloodbrain barrier. Despite the setbacks in clinical trials, ongoing research in $A \beta$-targeted therapies offers hope for more effective treatment strategies. This review underscores the need for further research and development to overcome the current obstacles in treating Alzheimer’s disease.