Dementia Drugs in Trials: UK and Worldwide

Dementia continues to impact millions worldwide, causing significant challenges with memory, thinking, and daily functioning, with Alzheimer's disease being the most prevalent form.  Over the past two years, from October 2023 to October 2025, researchers have made notable strides in testing new drugs aimed at slowing or halting the disease's progression.  This article provides an overview of key drugs in various trial phases during this period, including expected completion dates and results from concluded trials.  Drawing from recent reports and updates, we'll use straightforward language to make the information accessible, while including a section on trials anticipated to begin after 2025.

As a major global health concern, dementia affects over 55 million people, with projections suggesting this could double by 2050 without breakthroughs.

In the UK alone, more than a million individuals are expected to live with dementia by 2025, rising to two million by 2051.

While existing medications manage symptoms like confusion, emerging therapies target underlying causes such as protein build-ups in the brain.  Clinical trials evaluate safety and efficacy across phases: Phase 1 focuses on safety in small groups, Phase 2 assesses benefits in moderate-sized cohorts, and Phase 3 confirms results in large populations, often leading to regulatory approval.

The last two years have sparked optimism, with approvals for drugs like lecanemab and donanemab in the US and UK.  These anti-amyloid therapies clear harmful plaques from the brain, slowing decline by 27% to 35% in early-stage patients.

However, they come with risks like brain swelling or bleeding, affecting up to 30% in some trials.

These advancements represent a shift toward disease-modifying treatments, fuelling a robust pipeline.  As of January 2025, 182 trials are evaluating 138 novel drugs, a 9% increase from the previous year, with most targeting Alzheimer's.

The UK contributes significantly, hosting around 9% of global trials, supported by organisations like Alzheimer's Research UK and government-funded hubs.

We'll break down the drugs by phase, highlighting those active or concluded since October 2023, with start dates where available, expected end dates, and outcomes for finished trials.  Data is sourced from recent pipeline reports and updates as of late October 2025.