Pharmacological Interventions to Attenuate Alzheimer's Disease Progression: The Story So Far.

Alzheimer's disease (AD) is a progressive neurodegenerative disease and the most common cause of dementia in the elderly. Up to date, the available pharmacological options for AD are limited to cholinesterase inhibitors and memantine that may only provide modest symptomatic management with no significance in slowing down the disease progression. Over the past three decades, the increased interest in and the understanding of AD major pathological hallmarks have provided an insight into the mechanisms mediating its pathogenesis, which in turn introduced a number of hypotheses and novel targets for the treatment of AD. Initially, targeting amyloid-beta and tau protein was considered the most promising therapeutic approach. However, further investigations have identified other major players, such as neuroinflammation, impaired insulin signalling and defective autophagy, that may contribute to the disease progression. While some promising drugs are currently being investigated in human studies, the majority of the previously developed medical agents have come to an end in clinical trials, as they have failed to illustrate any beneficial outcome. This review aims to discuss the different introduced approaches to alleviate AD progression; in addition, provides a comprehensive overview of the drugs in the development phase as well as their mode of action and an update of their status in clinical trials.