The United States of America has approved the use of the first drug to slow the progression of Alzheimer's disease, and Canada may follow soon.

"Lecanemab," also known by the brand name "Leqembi," is the first available treatment for Alzheimer's disease in North America.

Donald Weaver, director and chief scientist at the Krembil Research Institute in the University Health Network, told CTV on Friday that this modified drug is not a cure for the disease but a step in the right direction.

Weaver explained that the drug binds to and prevents the amyloid protein from clumping and accumulating in the brain, noting that many people believe that amyloid is key to the causes of Alzheimer's disease.

Weaver confirmed that when studying the drug, it showed a 27% improvement in memory compared to expanding abilities and cognitive functions over six months, indicating that one could be able to stay at home for six months and might be able to recognize and interact with their family on a clearer level, emphasizing that six months is a significant amount of time.

In 2020, 597,300 people were reported to have Alzheimer's disease or any other form of dementia in Canada, and it is expected that more than 950,000 people will be diagnosed with the disease by 2030, according to the Alzheimer's Society of Canada.

The newly approved drug works only for certain individuals, and Weaver said the drug must be taken either in the very early stages of Alzheimer's disease or before moderate cognitive impairment, meaning that people with more advanced forms of Alzheimer's may not benefit from it.

An 18-month study published in November 2022 found that the drug may carry risks of serious side effects for some patients, as nearly 13% of 1,795 people who participated in the trial experienced side effects such as brain swelling or bleeding.

Although the recent approval by the U.S. Food and Drug Administration does not affect Canadians at the moment, Weaver said their experience will help other countries make decisions. The drug was submitted for approval by Health Canada in May.