Alzheimer’s drugs offer some hope

Article content

Each year, Dr. Andrew Frank and his colleagues at the Bruyère Memory Program serve thousands of patients and their families seeking answers about whether or not they have dementia.

For a growing number of those patients, the answer is yes – a diagnosis that is often devastating for individuals and families. Every year it is more common.

Article content

“Referrals have increased steadily over the past 10 years. “We’ve seen a definite increase,” Frank said.

Article content

In Ontario alone, there has been a 48 per cent increase in dementia patients since 2010, according to a recent analysis by the Ontario Medical Association. The Alzheimer’s Society anticipates that the number of people across Canada who will live with dementia over the next 30 years will increase by 187 per cent.

In that context, efforts to develop new drugs to slow the progression of Alzheimer’s disease, the most common cause of dementia, have been highly anticipated and even hailed as potential game-changers for Alzheimer’s patients.

Doctors, like Frank, who work with dementia patients, have been watching closely how The United States approved a new treatment for Alzheimer’s and Health Canada began reviewing the drug.

That drug, known as Lecanemab, is neither a miracle nor a cure, Frank warns. But cognitive neurologist and Memory Program researcher Bruyère believes the drug, and others like it in the pipeline, represent progress in a field that has seen little movement in recent years. Frank would like to see it approved in Canada, despite some complicating factors.

Article content

“It is a clear advance in our treatment options, which can lead to significant cognitive and functional benefit over time, especially if started early in the disease. In this way, it can provide hope in a field that often lacks hope and can push the public to prioritize brain health and its preservation,” Frank said.

Last summer, the U.S. Food and Drug Administration gave full approval to the drug, which in double-blind clinical trials was shown to reduce the progression of Alzheimer’s disease by 27 percent. That means patients who received treatment as part of the study experienced a slowdown in the progression of their disease. They continued to get worse, but at a slower rate than those who were not on treatment.

Health Canada accepted the drug for review in May 2023 and Frank said the outcome of that review is expected this spring.

Lecanemab, produced by pharmaceutical companies Eisai and Biogen, is an antibody that targets amyloid beta protein, one of two proteins whose sticky plaque is toxic to brain cells and are a hallmark of Alzheimer’s disease.

Article content

For 15 to 20 years, other antibody treatments for Alzheimer’s have gone through clinical trials and failed, Frank said. He describes the latest development as encouraging.

“It is the first successful trial (for the treatment of) Alzheimer’s since 2006 and attacks what we believe is the root cause: the toxic amyloid protein.” That protein, she said, starts a cascade of damage to brain cells that can destroy people’s lives.

“With the aging population, this is becoming more and more common.”

Bruyère was one of the sites where a clinical trial of a second antibody treatment targeting amyloid was carried out. That drug, Donanemab, saw a 35 percent decline rate among Alzheimer’s patients who were treated versus those who were not. It also had a higher risk of complications than Lecanemab. It is not currently approved by Health Canada.

Lecanemab is administered intravenously, every two weeks. The most important possible side effect is swelling or bleeding in the brain in 10 to 15 percent of patients. It can be asymptomatic or cause headaches, dizziness, vision changes or even stroke-like symptoms, Frank said. If treatment is stopped, most patients recover completely, but a small number may not recover.

Article content

Because of that risk, any real-world use of the treatment would require routine use of MRIs to detect swelling or bleeding. The treatment would also require testing to ensure that patients have amyloid protein to benefit from the treatment, Frank said. Those would be additional costs to the health system for using an already expensive drug: in the United States, its price has been set at $26,500 a year.

If Health Canada determines that the benefit of the drug outweighs the risk after reviewing its safety, effectiveness and quality, it would issue a compliance notice. Only then are decisions made about whether drug costs will be covered by publicly funded federal, provincial and territorial drug plans.

Dr. Saskia Sivananthan, an associate professor in McGill’s department of family medicine and former head of research at the Alzheimer’s Society of Canada, said there are more questions to consider around these drugs, among the first developed for Alzheimer’s that target its underlying cause.

Among those problems, Canada does not have enough imaging technology to meet requirements for monitoring patients using these medications. He also noted that Alzheimer’s disease is widely underdiagnosed in Canada (by up to 50 per cent), limiting the ability to participate in clinical trials. He noted that the drugs could be approved for feasibility studies and other specific uses rather than for more general use.

Article content

She says there is growing hope within the Alzheimer’s community not only because of Lecanemab and Donanemab, but because there are many potential medications in the pipeline.

“They are not a silver bullet,” Sivananthan said. “They are not going to cure dementia and they are nowhere near the kind of impact that people living with dementia want. But they are a start.”

Frank says he believes it is important for the drug to leave the world of clinical trials and “enter the real world,” where its value as a treatment for patients in the early stages of Alzheimer’s disease can be better understood.

Even if it is not covered by public drug plans, Frank said it could be covered through private health insurance and on a compassionate basis for some patients, something Frank would like to see offered to some Bruyère patients.

“If Health Canada approves it, we hope to be one of the sites across Canada that has compassionate use through the company to offer it at no cost to mildly affected people.”

Frank acknowledges that some believe the drug’s benefit is not enough to outweigh any risk (patients taking it in clinical trials continued to get worse, but at a slower rate), but that, he said, is not the general consensus.

Article content

The fact that there are not just one, but two new drugs showing some success in attacking the amyloid protein is a long-needed positive sign, he said. And that could make a difference in the lives of people and families affected by Alzheimer’s disease.

“Fortunately, we are making some progress on an important public health need. Here is a step forward.”

Our website is your destination for the latest news, so be sure to bookmark our homepage and Subscribe to our newsletters so we can keep you informed.

Article content