News that a potential treatment for early stage Alzheimer’s disease can slow cognitive decline is a significant development in dementia research.

About the drug

Lecanemab is an antibody that is designed to remove toxic beta-amyloid deposits; proteins that build up in the brains of people with Alzheimer’s disease.

Following phase 3 clinical trials, pharmaceutical companies Eisai and Biogen have said that the cognition of Alzheimer’s patients given the drug, declined by 27% less than those on placebo (dummy drug). Full results will be presented later in the year.

Key role of Join Dementia Research volunteers

The study called CLARITY-AD enrolled 1795 patients globally with early-stage Alzheimer’s, this included Join Dementia Research volunteers who took part in the UK clinical trials.

Participants injected lecanemab every two weeks and regularly had their memory and mental agility tested over an 18 month period.

Study results

The drug appears to reduce toxic plaques in the brain, thereby reducing the rate of decline in people’s memory and thinking.

The study adds strong support to affirm the amyloid hypothesis. Prior to this, dozens of other drug trials have failed, leading to questions about whether amyloid was really causing the disease.

A reduced decline of 27% is a modest change in clinical outcome but it is the first time any drug has been clearly shown to alter the disease’s trajectory.

Side effects included brain swelling and headaches, which is in line with the expectations of the pharmaceutical companies.

Eisai and Biogen are now applying for regulatory approval for the drug to be given in the US, Europe and Japan.

What does it mean?

Professor John O’Brien, NIHR Clinical Research Network National Speciality Lead for Dementia said: “This appears to be the first study to show highly significant benefits in people with Alzheimer’s disease from lowering amyloid levels in the brain, although there are some side effects.

“Without seeing the full results we cannot determine the clinical significance of the results and the likely benefit to patients, but from the information provided, this study appears to represent a major landmark on the way to treatments that can modify the disease process in dementia”.

A big thank you to all the Join Dementia Research volunteers who took part in this study and helped to test this new potential treatment.