Emerging treatments for Alzheimer's disease for non-amyloid and non-tau targets.

INTRODUCTION: The number of people with dementia, including Alzheimer's disease, is growing as a result of an ageing global population. Treatments available for AD only alleviate the symptoms of the disease, and are effective in some people with AD for a limited time. There is no disease-modifying treatment available, and despite research efforts, the underlying mechanisms of AD and optimal treatment targets have not been fully elucidated. Amyloid and tau are key pathological markers of AD with ongoing trials targeting both. However, there are also many trials at various stages of development that primarily target other markers and processes implicated in the disease, which are now being investigated. Areas covered: This review summarizes current treatment approaches for AD and explores both repositioned and novel therapies that target non amyloid and non tau mechanisms that are in the clinical trials pipeline. This includes treatments for cognitive and neuropsychiatric symptoms and potentially disease modifying therapies. The studies included in this review have been obtained from searches of PubMed and clinical trials databases. Expert commentary: There is a renewed energy in identifying better treatments for behavioural symptoms of AD using both novel drugs and repositioning existing drugs. Lack of success in clinical trials of drugs targeting amyloid and tau have led to a surge in targeting alternative mechanisms. Progress in the development of biomarkers will provide further tools for clinical trials of potential therapeutics for both symptomatic treatment and disease modification in AD.