Clinical trials
Clinical trials in the United States and the European Union
The main prevention trials of the anti-amyloid drugs are fully enrolled, a second-generation antibody is now recruiting, and several smaller prevention studies are open. Here is what is active and how to search for a trial near you.
Updated
Trial status changes monthly. Every entry links to its registry record, which is the authoritative source. Eligibility must be confirmed with the study team, and any decision to join a trial should involve your own clinician.
Recruiting now Checked 15 October 2026
- Phase 3USEU
A prevention trial of a second-generation "brain-shuttle" anti-amyloid antibody in people with no symptoms but biomarker evidence of amyloid. Plans call for about 1,600 participants. Trontinemab is given less often than first-generation antibodies and has shown less ARIA (brain swelling) in earlier studies.
- Phase 2US
Tests a cholesterol-lowering CETP inhibitor in people with preclinical Alzheimer's, a direct test of the heart-brain link described on the heart health page.
- Phase 2US
Tests whether the sleep medicine suvorexant, taken at night, lowers amyloid and tau in people at risk.
- Phase 2US
A platform trial testing several tau-directed treatments (including the AADvac1 vaccine) under one protocol.
- Phase 2
One of the few trials that specifically enrols APOE ε4 carriers. Listed here because 23andMe customers often ask; it is not in the US or EU.
- Phase 2/3USEU
For families with a known APP, PSEN1 or PSEN2 mutation. The 23andMe raw file can show some of these mutations, but a clinical test is required for enrolment.
- ScreeningUSEU
A blood-test screening study that routes eligible volunteers to treatment trials. A low-commitment way in for people who want to be considered.
Fully enrolled prevention trials (results pending)
- Phase 3USEU
1,621 cognitively healthy adults with elevated brain amyloid, 73 percent of them APOE ε4 carriers, randomised to four years of lecanemab or placebo. Screening used a plasma p-tau217 test followed by PET.
- Phase 3US
2,196 enrolled in the US and Japan; nearly half carry one APOE ε4 copy and 8 percent carry two. The trial ends when 350 participants show clinical worsening, so its date depends on how quickly people progress.
- Phase 3US
A subcutaneous successor to donanemab in people with preclinical disease or mild cognitive impairment; screening used the plasma p-tau217 test.
Approved treatments and what they mean for trials
Lecanemab (Leqembi) and donanemab (Kisunla) are approved in the United States for early symptomatic Alzheimer's with confirmed amyloid, and lecanemab is approved in the European Union with restrictions for APOE ε4 homozygotes because of their higher ARIA risk. Both slow decline by roughly a quarter to a third over 18 months. Neither is approved for people without symptoms, which is exactly the question the prevention trials above are designed to answer. In 2026 the Alzheimer's pipeline held about 158 drugs in 192 trials, with growing numbers of tau-directed and anti-inflammatory agents.
How to search the registries yourself
| Registry | Covers | How to use it |
|---|---|---|
| ClinicalTrials.gov | United States and most international trials | Search "Alzheimer Disease", filter to Recruiting, then add your country or city. Each record lists sites and contacts. |
| EU Clinical Trials Information System (CTIS) | Trials authorised in the EU and EEA since 2023 | Search "Alzheimer" and filter by member state. Newer EU trials appear here rather than in the older register. |
| EU Clinical Trials Register | EU trials registered before 2023 | Useful for older or long-running studies; most records give the matching NCT number. |
| Alzheimer's Association TrialMatch | United States | A free matching service: answer questions about yourself or a relative and receive trial suggestions. |
| BrightFocus Trial Finder | United States | Plain-language trial search with eligibility summaries. |
| Alzheimers.gov clinical trials finder | United States, NIA-supported | Government portal that also lists the NIA Alzheimer's Disease Research Centers, which run many trials. |
| Alzheimer Europe Clinical Trials Watch | Europe | Curated summaries of European dementia trials in plain language. |
| AlzPipeline | Global pipeline | Tracks every drug in development, by mechanism and phase. |
Questions to ask before joining
- What is the chance of receiving placebo, and is there an open-label extension afterwards?
- What scans, lumbar punctures or infusions are required, and how often?
- Will I learn my amyloid or APOE status, and is counselling provided?
- What are the known side effects, and how are APOE ε4 carriers monitored for ARIA?
- Can I take part if I have already received lecanemab or donanemab? Each sponsor decides individually.
- ClinicalTrials.gov records linked above, retrieved 15 October 2026 through the registry's public API (recruiting phase 2 and 3 Alzheimer's prevention and early-disease studies).
- Alzforum. Fully loaded: secondary prevention studies of lecanemab, donanemab. 15 November 2024. alzforum.org
- BrightFocus Foundation. Alzheimer's clinical trials 2026: an insider's look with Dr. Jeffrey Cummings. brightfocus.org