New hope as Alzheimer’s drug slows memory decline in phase 3 trial

Today (Wednesday 28 September), the pharmaceutical company, Eisai, reports positive results from its successful phase 3 clinical trial of the Alzheimer’s drug, lecanemab. The results show the drug was able to slow the rate of decline in people’s memory and thinking as well as function over 18 months, and also helped people with day-to-day activities.

The trial, known as Clarity AD included 1,795 people with early-stage Alzheimer’s and mild cognitive impairment (MCI) due to Alzheimer’s, who received a bi-weekly infusion of either lecanemab or a dummy drug (placebo).

Dr Susan Kohlhaas, Director of Research at Alzheimer’s Research UK, said:

“This is a historic moment for dementia research, as this is the first phase 3 trial of an Alzheimer’s drug in a generation to successfully slow cognitive decline. These results show that lecanemab slows the progression of memory and thinking problems in people with early Alzheimer’s, demonstrating a major breakthrough in dementia research. This is the first drug that’s been shown to not only remove the build-up of a protein called amyloid in the brain, but to have a small but statistically significant impact on cognitive decline in people with early-stage disease. The drug can also cause substantial side effects which will need to be considered. These top-line results, announced by the pharmaceutical company that make the drug, Eisai, offer new hope to people affected by this cruel and devastating disease. “Before a drug is made available, regulators in different parts of the world, including the UK, will still need to assess the full data to determine whether lecanemab is safe and effective enough to be used in people with Alzheimer’s. If the drug is approved, it is essential that it gets to the people who may benefit from it as quickly as possible. Now is the time to be making sure that our health system is set up to deliver life-changing treatments. In preparation for this, it’s vital that the Government’s new Dementia Mission focuses on ensuring the NHS is ready to roll out new licenced therapies as quickly as possible – right now only 1 in 3 psychiatry services would be ready to deliver a new treatment within a year. “Today’s results were only possible because of the volunteers who took part in this trial, previous studies of this drug and wider dementia research across the world. Eisai is now recruiting people with a high risk of Alzheimer’s who have not yet developed symptoms to take part in further trials, to determine whether the drug slows the disease when given at an even earlier stage. People can register their interest to take part in studies like these by signing up to Join Dementia Research by calling 0300 111 5 111. “This drug has only been tested for people in the early stages of Alzheimer’s and won’t be a silver bullet for all causes of dementia. At Alzheimer’s Research UK we will keep working to bring about more breakthroughs for people with all forms of dementia, including those in the later stages of disease. We hope today’s news will spark renewed investment in dementia research across the globe and political leadership to deliver the funding and infrastructure needed to make life-changing new treatments a reality.”

Lecanemab, previously known as BAN2410, is a drug designed to target and clear amyloid, one of the hallmark proteins that builds up in the brains of people with Alzheimer’s at an early stage of the disease.

CLARITY-AD recruited participants who had amyloid present in their brains. For those receiving the drug. treatment effects were seen as early as six months in. Of the people who experienced side effects, the most common were headaches and swelling in the brain known as “amyloid-related imaging abnormalities” (ARIA). These were experienced by 17% of those who received lecanemab but this was in line with the drug makers expectations.

Regulators will still need to assess the full data to determine whether lecanemab is safe and effective enough to be used in people with Alzheimer’s in different parts of the world. The drug maker, Esai, aims to file for approval in the US before Japan and Europe later next year. However, Alzheimer’s Research UK supporter, Alison Littleford, from Wolverhampton, whose husband Frank was diagnosed with Alzheimer’s disease in 2020, welcomed the news:

“This is very welcome news and although we don’t yet know if this is a drug that will be beneficial to Frank or if and when he would be able to be prescribed it, it is so important to us to see that research is making progress. “It has been so difficult to see a once articulate, confident, outgoing and sociable man become afraid, confused, embarrassed and dependant on me in such a short period of time. “But it is a great comfort to us, as it will be for so many families affected by Alzheimer’s, that there is hope that new treatments are on the horizon. “For Frank and me, and all people in our situation, we need to see all avenues being explored to find successful treatments and then get them to the people who so desperately need them.”