Clinical Trials in Focus: Alzheimer's Disease
Alzheimer's disease is a progressive and debilitating neurodegenerative disorder that causes problems with memory, thinking, and behaviour. It is the most common cause of dementia.
It is estimated that more than 6 million Americans are currently living with Alzheimer’s, this is expected to increase to nearly 13 million by the year 2050. Alzheimer’s disproportionately effects those from minority groups; Black Americans are twice as likely to develop the disease when compared to white Americans, and Hispanic groups are one and a half times more likely.
The research community are seeking to further understand Alzheimer's disease and identify ways to treat it. Many active clinical trials involves testing potential new therapies aimed at slowing or stopping the progression of Alzheimer's.
Research Focus Areas
Reducing beta-amyloid plaques and tau tangles - These are abnormal protein deposits that build up in the brains of Alzheimer's patients and are associated with nerve cell damage. Experimental drugs target plaques and tangles to try to reduce their accumulation.
Developing neuroprotective agents - Aiming to shield nerve cells and preserve cell-to-cell connections that are vital for cognitive functions.
Targeting inflammation and oxidative stress - Controlling damaging inflammatory processes and free radicals may help protect neurons.
Increasing acetylcholine levels - Boosting this important neurotransmitter can temporarily improve cognition and memory. It is the mechanism of existing Alzheimer's medications.
Advancing early detection - Detecting Alzheimer's earlier through diagnostic tools and biomarkers allows treatment to potentially be more successful.
Testing cognitive training and lifestyle interventions - Engaging in mentally stimulating activities and social interaction may help strengthen cognitive reserves.
There are few active clinical trials for Alzheimer’s Disease listed on clinicaltrials.gov (84 Recruiting, 16 Not Yet Recruiting, and 23 Active Not Recruiting).
Clinical Trial Challenges
Patient Recruitment – It can be difficult to recruit enough patients who meet the eligibility criteria for trials, this is especially the case in the early stages of the disease when patients may not know they have Alzheimer’s.
Patient Retention – Patients are more likely to drop out of a trial as their condition progresses, leading to complications in gathering accurate data.
Age-related comorbidities - Older Alzheimer's patients often have other health issues that may impact trial results, eligibility, and recruitment.
Disease heterogeneity - Alzheimer's has variations in symptoms and progression rate across patients.
Choosing appropriate clinical endpoints - Identifying outcome measures sensitive to treatment response has been an obstacle due to an inability accurately record changes in cognitive function.
Despite these hurdles, Alzheimer’s Disease clinical research has achieved significant advancements in recent years
Eli Lilly: Trialling the donanemab drug in the TRAILBLAZER-ALZ2 on 1,182 patients. Early data has showed 40% of participants experiencing a slowing decline.
Eisai: Lecanemab was fully approved by the FDA in July 2023, and data from trials has shown that the drug is effective at slowing disease progression by 27%.
Eli Lilly: Commencing in August 2022 (due to end in 2025), Remternetug is trialled in Phase 3 development. Early data shared demonstrated that treatment had amyloid cleared from brains in 75% of participants.
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