Experts temper hope for new FDA-approved Alzheimer’s drug

When US authorities approved a new Alzheimer’s drug in early January, Howard Chertkow had this feeling: déjà vu.

In 2021, Dr Chertkow, scientific director of the Canadian Consortium on Neurodegeneration and Aging, and his colleagues Health Canada warned A drug for Alzheimer’s disease called aducanumab, which has been approved in the United States, has not shown sufficient clinical benefit and may actually harm patients. However, the pharmaceutical company later withdrew its application for approval from Health Canada.

Just months later, a new drug, lecanemab, was approved. accelerated approval Some similar concerns were raised by the US Food and Drug Administration on January 6th.

Dr. Chertkow, senior scientist at the Baycrest Academic Health Science Center in Toronto, said:

Marketed under the brand name Leqembi, Lecanemab is It is the second Alzheimer’s disease drug to receive US regulatory approval in 20 years. Like aducanumab, it targets amyloid beta, a sticky protein fragment that accumulates in the brain. Likewise, some experts are softening the hopes they bring to their warned patients.

Both drugs are designed to clear amyloid-beta from the brains of patients in the early stages of the disease, with the goal of slowing the decline. This is a proposed explanation for Alzheimer’s disease that suggests that accumulation of toxic amyloid plaques ultimately causes dementia.

However, this hypothesis has been questioned as some believe that amyloid may be only part of the puzzle. Dr. Chertkow said removing excess substances, such as iron, in patients with pneumonia eliminates symptoms and cures the disease. However, this is not the case for amyloid and Alzheimer’s disease.

Furthermore, the amyloid hypothesis suggests that if people have amyloid in their brains, they will develop dementia. have been challenged by, said Dr. Chertkow.

Neither aducanumab nor lecanemab can cure Alzheimer’s disease, but they may give patients more time.

according to Canadian Alzheimer’s AssociationAlzheimer’s disease is one of the most common forms of dementia, and while drugs are available to help treat it, symptoms do not reverse or stop the progression of the disease. .

Dr. Chertkow said the evidence provided for lecanemab is stronger than for aducanumab in that drug trials have shown clinical benefit. But what that means for patients is unclear.

“Does that mean it stands out? That’s a big question,” he said, noting that patients could progress to mild-to-severe dementia in four to five years instead of three to four years. I explained that there is

According to December editorial In the Lancet journal, differences in lecanemab made in clinical trials on tests of participants’ cognitive and functional symptom severity “may not be clinically meaningful”. Participants also noted that they developed side effects called amyloid-related imaging abnormalities (ARIA). This is usually accompanied by temporary swelling of the brain, which was mostly asymptomatic.

The Lancet said it remains to be seen if lecanemab is the game-changer some have suggested.At the moment, it said key public health messages include targeting. Modifiable risk factors For dementia such as high blood pressure, smoking, diabetes, and obesity.

A spokesperson for Eisai Co., Ltd., the pharmaceutical company that makes lecanemab, said in an email that lecanemab has not yet been submitted to Health Canada for approval, and there is no information as to when that will be done. Stated.

Biogen Canada Inc. withdrew It submitted aducanumab for regulatory review by Health Canada in 2022, saying the agency indicated the data provided was insufficient to support marketing approval in the country.

Kathy Barrick, chief executive of the Alzheimer’s Association of Ontario, expects it will take some time for both drugs to go through the approval process in Canada. said it was encouraging and would be disappointed if Health Canada did not finally approve it.

Even giving patients a little more time is better than nothing, she said, and it gives them hope that science is on the right track despite its limitations.

“These are not miracle cures. They come with some pretty serious side effects. I’m just asking.”

Barrick stressed that Canada needs to be prepared for the eventual introduction of treatments that improve Alzheimer’s disease. She expects it will only add to the already long wait times to see a neurologist. There is a need to improve access to get these types of drugs to those who need them, she said. Both lecanemab and aducanumab are given intravenously and require monitoring.

Cost is another consideration.Eisai will reduce the price of lecanemab to US$26,500 per patient per year. The question of whether it would be covered by provincial health plans, if eventually approved in Canada, would require serious debate, Dr. Chertkow said.

“With a single payment system, the question is whether it’s worth making it accessible to everyone.” He added that a framework is needed to deal with

Chertkow said he thinks lecanemab is a small step in the right direction. But there are other potential drugs in the pipeline, including those that don’t rely on the amyloid hypothesis.

Future treatments for Alzheimer’s disease may include different treatments for different people, he said.

“There’s a lot of other iron in the fire. So I don’t want people to lose hope that this is the best that science can come up with. That’s it.”