From pathology to precision therapy: Contemporary and emerging strategies in Alzheimer's disease treatment.

Alzheimer's disease (AD) is a progressive neurodegenerative disease characterised by dementia, confusion, irritability, a lack of cognition, and mood swings. Since its discovery in 1906, many small molecules have been designed to block disease progression by targeting the primary targets β-amyloid and tau proteins. Subsequent research focused on small-molecule inhibitors targeting secondary targets, such as β-secretases and γ-secretases. However, the clinically approved conventional therapies include acetylcholinesterase inhibitors and N-methyl-D-aspartate inhibitors that relieve only disease symptoms, and their efficacy remains limited. Recently, approved novel approaches, such as monoclonal antibodies and vaccines, aim to slow disease progression by targeting the molecular mechanisms underlying amyloid and tau proteins. In addition, these drugs have controversial side effects, which call into question their therapeutic efficacy. A newer strategy involving small peptides is gaining traction because of their lower toxicity, improved permeability, and target specificity. Various homogenous and heterogeneous peptidomimetic inhibitors have been designed to target traditional protein targets. Although various peptidomimetic inhibitors have demonstrated therapeutic efficacy, none have entered clinical trials. Upon conducting an extensive literature survey, we identified several regions, targets, and technologies that could be leveraged to ameliorate Alzheimer's disease progression. In this review, we address the progression of AD, its historical context, and the development of therapeutic approaches that target this disease. We focus on the evolution of subsequent therapies aimed at alleviating the disease and highlight recent developments in drug delivery and formulation techniques that enhance therapeutic efficacy and address the shortcomings of traditional treatments.