World Alzheimer’s Month 2024

Pathologically, AD is characterised by the accumulation of toxic amyloid-beta plaques, tau tangles and neuroinflammation in the brain, which ultimately result in irreversible neuronal loss [5,6]. Consequently, people with AD experience a progressive decline in cognitive function, which eventually interferes with their ability to perform everyday tasks unassisted.

Momentum in AD research is now shifting towards disease-modifying therapies (DMTs), which aim to alter the course of disease progression. In 2021, there were 97 DMTs in AD clinical trial pipelines and this effort is translating to the availability of new therapies [7].

In August 2024, lecanemab was the first DMT for Alzheimer’s disease to receive approval from the Medicines and Healthcare products Regulatory Agency (MHRA) in the UK. However, despite positive clinical evidence lecanemab was not approved for use in the NHS in the preliminary decision by NICE. This decision was driven in part by the significant costs associated with providing the treatment, including the cost of giving the infusion, monitoring scans and outpatient reviews [8]. As real-world experience accumulates, any long-term benefits associated with the disease-modifying mechanism will be available to support future decisions.

With an aging population and increasing prevalence of risk factors (e.g. type 2 diabetes) [9], the need for effective AD treatments is higher than ever. Healthcare systems will need to respond in preparedness for the rollout of new AD interventions and DMTs. Key issues to be addressed include the need for superior diagnostic tools to identify those eligible and allow for earlier intervention. AD pathology is thought to begin 20 years or more before symptoms start to develop, and many people present with mild cognitive impairment prior to an AD diagnosis [10]. Early intervention is likely required for successful treatment interventions and will be a crucial factor in improving patient outcomes. Indeed, lecanemab is only available for people with early Alzheimer’s disease, and many experts suspect it is unlikely to work in the later stages when neuronal loss is too high [11]. Other factors healthcare systems need to address are the infrastructure and equipment needed for the large-scale administration of new therapies, and the economic cost associated with this [12].

Fortunately, the potential for prevention is high. The 2024 Lancet Commission report for dementia suggested nearly half of dementia cases with no known genetic cause could be prevented or delayed by addressing 14 modifiable risk factors, such as high LDL cholesterol, type 2 diabetes and vascular damage [13]. Existing drugs used to modify these risk factors in other patient populations, such as diabetes are being investigated in relation to lowering the risk of dementia [14].

Following the approval of the first new AD drugs in 20 years, the future for AD therapies looks positive.