A new experimental drug, lekanemab, from Eisai (Japan) and Biogen (USA), offers hope to Alzheimer’s patients by slightly slowing cognitive decline, clinical trial results show.

The breakthrough in research has ended decades of failure and shows that a new era of drugs to treat Alzheimer’s disease – the most common form of dementia – is possible.

However, lekanemab has only a small effect, and its impact on people’s daily lives is being studied.

Also, the drug works in the early stages of the disease, so most people would miss this opportunity if the disease was diagnosed late.

How the drug works

Lecanemab targets the sticky, toxic beta-amyloid protein plaques that build up in the brains of Alzheimer’s patients, progressively destroying vital neuronal cells and thus their memory and cognition. According to Eisai, after 18 months of testing, 68% of people who took the drug were cleared of these brain plaques. Until now, any medication only allows you to better cope with the symptoms, but none of them can change the course of the disease in the direction of deterioration.

One of the world’s leading researchers behind the whole idea of ​​targeting amyloid, Professor John Hardy, called the results “historic” and expressed optimism that “we are seeing the beginning of a cure for Alzheimer’s.” Professor Tara Spears Jones of the University of Edinburgh said the results were “a big deal because we had a 100% failure rate for a long time.”

Currently, people with Alzheimer’s disease are prescribed other drugs to help manage their symptoms, but none of them change the course of the disease.

Lecanemab is an antibody, similar to the ones the body makes to fight viruses or bacteria, designed to instruct the immune system to clear amyloid from the brain.

Amyloid is a protein that accumulates in the spaces between neurons in the brain and forms plaques, which are one of the hallmarks of Alzheimer’s disease.

The large-scale trial involved 1,795 volunteers with early-stage Alzheimer’s disease. Injections of the drug were carried out every two weeks.

The results presented at the Alzheimer’s Clinical Trials conference in San Francisco and published in the New England Journal of Medicine are not a miracle cure. The disease continued to rob patients of their brainpower, but that decline slowed by about a quarter over the 18 months of treatment.

The data is already being evaluated by US regulators, who will soon decide whether the drug can be approved for wider use. Pharmaceutical companies Eisai and Biogen plan to start the approval process in other countries next year.

The test was attended by David Esham, who is 78 years old, he is from Kent, UK.

Alzheimer’s disease forced him to quit his job as a carpenter – he could no longer remember how to build a closet or use tools.

“He is not the same person he used to be, he needs help with most things, his memory is almost non-existent,” said his wife Cheryl. However, the announcements gave hope to the family.

David said: “If someone can slow down the disease and eventually ‘stop’ it, that would be great, it’s just horribly ugly.”

There are more than 55 million people like David in the world and the number of Alzheimer’s patients is predicted to exceed 139 million by 2050.

Side effects

But there are also risks such as cerebral hemorrhage (17% of participants) and cerebral edema (13%). Overall, 7% of people taking the drug had to stop taking it due to side effects. In fact, during drug trials, two deaths from cerebral hemorrhage were reported (a 65-year-old woman and an 87-year-old woman who were also taking anticoagulant drugs), which initially led to a drop in the share of the two companies in the stock market. They deny that the death was due to their drugs.

However, the critical question is what will happen after 18 months of ongoing testing, and there is only speculation on this score.

Dr Elizabeth Coulthard, who works with patients at the NHS Trust in North Bristol, says people have an average of six years of independent living after mild cognitive impairment sets in.

Slow down that decline by a quarter and that could mean an extra 19 months of independent living, “but we don’t know that yet,” he says.

However, experts note that medication must be given early in the disease before too much brain damage is caused, and most people with memory problems are in the advanced stages.

This suggests that people should see a doctor at the first sign of memory problems, and that doctors can refer them for amyloid testing — with a CT scan, MRI, or lumbar puncture — to determine if they have Alzheimer’s disease or another form of dementia. Currently, only 1-2% of people with dementia have such tests.

In fact, Dr. Coulthard said the only ones likely to win at this time are those who live near major medical centers or have private insurance.

The scientists also stressed that amyloid is only part of the complex picture of Alzheimer’s disease and should not be the only treatment option.

The immune system and inflammation are heavily involved in the disease, and another toxic protein called “tau” is the site of brain cell death.

Source: BBC, APE-MPE.