Exciting new drug is ‘beginning of the end’ for Alzheimer’s – so what is it and when could it be available?

At long last, it seems a drug has been found to treat Alzheimer’s disease.

Lecanemab has been shown in trials to slow the progress of early-stage Alzheimer’s – scientists found that after 18 months, the drug slowed disease progression by 27% compared with patients taking a placebo.

Tokyo-based pharmaceutical Eisai, who has partnered with US biotech firm Biogen to develop lecanemab, reported the phase three clinical trial results – which have been hailed by dementia researchers as a major step forward in the treatment of Alzheimer’s.

Professor John Hardy, group leader at the UK Dementia Research Institute (UKDRI) at University College London, says: “This trial is an important first step, and I truly believe it represents the beginning of the end.”

So, what does the drug do, who will it help, and when is it likely to be available?

We asked Sian Gregory, research information manager at the Alzheimer’s Society (alzheimers.org.uk), to explain…

What does lecanemab do?

“This drug is a disease-modifying treatment, which targets the amyloid protein build-up in the brain in Alzheimer’s disease. It sticks to these amyloid protein build-ups and essentially marks them for clearance and the brain’s immune system will clear them away.

“Research we funded 30 years ago with Professor Hardy showed amyloid was the key player in the causes of Alzheimer’s disease, and the theory is that removing the amount of amyloid in the brain reduces the toxic effect it’s having on brain cells, which will slow down the damage done to those cells and how quickly they die,” Gregory explains.

“It’s the first treatment that targets this root cause and is of benefit to how quickly Alzheimer’s progresses and gets worse. We’ve not seen that before from previous clinical trials. It’s slowing down how quickly the symptoms get worse, and giving people longer with a quality of life.

“It’s not a cure, but it’s a fantastic first step in our development of new treatments, because the treatments we have at the moment just improve the daily symptoms, but don’t do anything about the root causes.”

Who will the drug help?

“Because this drug targets amyloids, it’s just for people who have Alzheimer’s disease, not everyone who has dementia, unfortunately. There are lots of different types of dementia, although Alzheimer’s disease is what affects the majority,” says Gregory.

”When is lecanemab likely to be available?

“It needs to be approved before it can be available, and it would have to be approved in Europe by the European Commission, and by the Medicines and Healthcare products Regulatory Agency (MHRA)in the UK.

The producers have said they’ll submit an application for it to be approved in March 2023, and we’re expecting a decision on it in Europe by 2024, so we should hear then whether it’s been approved and will therefore be available.