Clinical trials on dementia: bridging access and innovation

The landscape of dementia clinical trials in Europe is focused on AD, the most common form of dementia. According to data from clinical trials registries, Europe has approximately 50 active AD clinical trials investigating various aspects of AD treatment, spanning all phases of drug development. The focus on these trials spans a variety of mechanism of action, with an emphasis on disease-modifying treatments that aim to alter the underlying pathophysiology of AD. The majority of clinical trials focus on people with mild cognitive impairment (MCI) and mild dementia due to AD, often referred to as early AD (Figure 1). However, phase 3 trials also address important aspects of AD management, including the treatment of agitation and psychosis associated with AD. These trials aim to not only alter the disease course but also improve the overall quality of life for people at various stages of AD.

To address the complexity surrounding access to clinical trials for AD, Alzheimer Europe launched the Clinical Trials Watch (CTW) in 2016 as a user-friendly, web-based resource designed to make information about clinical trials in AD and other dementias more accessible to people living with dementia, their carers and the wider public. This platform aims to offer a comprehensive view of ongoing trials, although it is not exhaustive. All the clinical trials included are recruiting participants in at least one European country and the content is updated regularly, based on information available on public registries.

For this resource, Alzheimer Europe collaborates closely, with members of its European Working Group of People with Dementia (EWGPWD) and European Dementia Carers Working Group (EDCWG) to ensure the information is understandable for a lay person, regardless of whether the person has a diagnosis of dementia. Pharmaceutical companies and study sponsors are also asked to provide feedback to ensure the scientific accuracy of the information.

Figure 1: Distribution of phase 2 and 3 clinical trials by AD stage and/or disease target
Source: Alzheimer Europe supplement on clinical trials on dementia in Europe, October 2024

Insights from the CTW underscore the need for more streamlined regulatory processes on one hand, and for sustained investment in clinical research on the other. First, there are significant differences between European countries in terms of the number of clinical trials open for recruitment. In a number of small and mostly Eastern countries, it is impossible for volunteers to take part in a clinical trial. Additionally, while Europe remains a key participant in global dementia-trial activity, it faces specific challenges in competitiveness. Globally, more trials are conducted in the United States than in any other global region (Figure 2).

These differences could be influenced by several factors including regulatory environments, resource allocation, infrastructure and population diversity. Addressing these challenges requires a concerted effort from global health authorities, research institutions and funding bodies to ensure that clinical trials are conducted efficiently and effectively. Although the dementia research ecosystem has begun to implement new and promising approaches to improve the accessibility, efficiency and equity of clinical trials, it is important to note that these innovations require sustained investment to succeed.

Clinical trials are often conducted at specialised research centres, which may be located in urban or academic settings. This can pose difficulties for participants living in rural or remote areas, who may have limited access to these centres. Major advances in the last decade in digital technologies and decentralised trials have opened a window of opportunity to introduce new methods into clinical trials, creating a more inclusive and effective trial environment for participants. These innovations can address logistical and geographic challenges by bringing trial-related services closer to participants, such as home visits for assessments and sample collection when feasible, and satellite sites deploying mobile clinics to reach participants in rural or underserved areas.

In Europe, new regulatory strategies have also been implemented by the European Medicines Agency (EMA) to enhance the availability and accessibility of clinical trials for AD. Initiatives such as the EU Clinical Trials Regulation (CTR) and the Accelerating Clinical Trials in the EU (ACT EU) programme aim to harmonise regulatory processes, improve coordination and foster cross-border collaboration to make Europe a more attractive and efficient region for clinical research.

“Alzheimer Europe remains committed to a holistic approach to AD and other
types of dementia where innovative new treatments are included alongside counselling, support and adequate care of people with dementia and their carers throughout the disease process.”

Recent clinical trials of anti-amyloid drugs have marked a turning point in the field, leading to the approval of the first disease-modifying therapies for AD in several global regions. While these drugs represent hope for many people with AD, the benefits and risks of treatment are multifaceted and complex, as are the findings from high-profile clinical trials of drugs such as lecanemab and donanemab. Access to these innovative drugs will pose a major challenge, as inadequate resourcing of European healthcare systems excludes many from accessing a timely diagnosis, as well as patient-centred support, care and treatments.

In January 2024, Alzheimer Europe launched a position paper on anti-amyloid therapies for AD, calling for concrete actions from industry, regulators, payers, healthcare systems and governments to ensure safe, timely and equitable access to these innovative medicines, for all people with early AD who could benefit from treatment.