Alzheimer's vaccine aims to clear amyloid before memory fades

NCT ID NCT07827768

What the study statuses mean

This study's is highlighted.

Recruitment status, easiest to join first

Recruiting now
This trial is taking on new participants right now.
Not yet recruiting This study
Registered, but not yet taking participants.
By invitation only
Not open to general applications. Only people the study team invites can take part.
Paused
Paused for now. It may or may not start again.
Ongoing
Running, but no longer taking on new participants.
Completed
The trial has finished. Results may not be published yet.
Stopped early
Stopped early, before it reached the end. That can be for many reasons, including safety.
Cancelled
Cancelled before anyone took part.

Expanded access (not trials)

Expanded access
Not a trial. This treatment can be requested outside a study, case by case, for people who qualify.
Expanded access (paused)
Not a trial. The treatment can normally be requested outside a study, but is unavailable right now.
Expanded access (ended)
Not a trial. The treatment could once be requested outside a study, but no longer can.
Approved
The treatment has been approved, so it is available normally rather than through this programme.

When the status isn't known

Details not published
The full record has not been published yet, so there is little to show here.
Status unknown
This status has not been confirmed recently, so it may be out of date.

First seen Sep 18, 2026 · Last updated Sep 18, 2026

Summary

Researchers are testing an experimental vaccine called AV-1959R in adults aged 55 to 80 who have amyloid buildup in the brain but no memory or thinking problems. The trial compares the vaccine with a placebo to see whether it is safe, triggers an immune response, and lowers brain amyloid. About 160 participants receive three injections over 44 weeks and are followed for 78 weeks.

What this could mean

Our plain-language read of the trial. This is informational only, not medical advice or a prediction.

Active substance
an experimental amyloid-beta vaccine called AV-1959R
What this could lead to
If it works, this vaccine approach could offer a way to clear or lower brain amyloid before memory problems start, possibly delaying Alzheimer's disease.
What could go wrong
This is a Phase 2 trial, so safety and effectiveness are still unproven. Vaccines that target amyloid can trigger brain swelling or small bleeds, and the immune response may not be strong enough to matter.

This is an AI summary of the original study and may miss details. Read our disclaimer.

Study facts

What this study's own registry entry says, in plain language.

Phase

Phase 2

Tests whether the treatment actually works, and watches for side effects, in a larger group.

Participants

About 160 people

The number the study aims to enrol. It can still change while the study runs.

Expected to start

Mar 2027

An estimate. Start dates often move.

Expected to finish

Jun 2029

An estimate. End dates often move.

Lead sponsor

Other sponsor

The registry's catch-all category, for sponsors it does not file as a company, a government agency, or a research network.

Who can take part

This study's own entry requirements. Only the study team can say for certain whether you qualify.

Ages

55 to 80 years

Sex

Anyone

Healthy volunteers

Not accepted

This study is not open to healthy volunteers. The entry requirements below say who it is open to.

Show the full entry requirements

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: Male or female participants 55 to 80 years of age, inclusive, at screening. Signed informed consent before initiation of study-related procedures. Cognitively unimpaired participants with preclinical Alzheimer's disease meeting all of the following: CDR global score = 0 at screening. MMSE score ≥26 at screening, with education adjustment. Plasma p-tau217/Aβ1-42 ratio ≥0.00738. Vision and hearing sufficient to comply with study procedures, in the investigator's judgment. Stable concomitant medications for management of existing medical conditions, as appropriate. Women must be of non-childbearing potential as defined in the protocol. Men must meet protocol-defined contraception and sperm donation requirements. Ability, in the investigator's opinion, to understand the study and comply with study requirements. Exclusion Criteria: Screening MRI showing clinically significant abnormalities, including protocol-defined infarcts, excessive microbleeds, leptomeningeal hemosiderosis, superficial siderosis, or ARIA-E. Contraindication to MRI. Serious illness requiring systemic treatment and/or hospitalization within 4 weeks before study entry. Clinically relevant cardiovascular, respiratory, gastrointestinal, endocrine, immunologic, hematologic, neurologic, or other systemic disease that could interfere with participation or follow-up. Insulin-dependent diabetes. Clinically significant ECG abnormalities, including protocol-defined conduction abnormalities or QTc abnormalities. Pre-existing autoimmune disease. History of seizure disorder, except protocol-permitted use of certain antiepileptic medications for chronic pain. Any medical, psychological, or social condition that may interfere with participation, compliance, or safety. Participation in another investigational drug study or use of an investigational drug within 30 days or 5 half-lives, whichever is longer, before dosing. Prior amyloid-beta or tau immunotherapy, including vaccine or monoclonal antibody, within 1 year before screening. Recent use of protocol-defined immunomodulatory or growth-stimulating agents. Chronic use of protocol-defined anticoagulants or antiplatelet agents; aspirin is permitted. Parenteral use of immunoglobulin preparations, blood products, or plasma derivatives. History of severe local or systemic vaccine reactions or significant allergic reactions. Clinically significant laboratory abnormalities at screening. Positive testing for HIV-1/2, hepatitis B surface antigen, or hepatitis C virus.

Get updates

Get notified about this study

Sign up to get updates when this study changes or when new studies for Alzheimer disease are added.

Our safety recommendation!

By submitting, you agree to our Terms of use

Conditions

The condition(s) this trial relates to.

Alzheimer disease Plaque, Amyloid

As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

How to take part

Only the study team decides who joins. These are the ways to reach them.

  1. The official record

    ClinicalTrials.gov lists the study team's own contact details, including names and phone numbers. We don't republish those.

    Open the record ↗

  2. A doctor treating you

    A doctor who knows your case can contact a study site on your behalf, and can tell you whether this study is worth pursuing at all.

More trials for these conditions

Other studies related to the condition(s) this trial covers.