Health

Alzheimer’s drug donanemab has been hailed as a ‘turning point’ for treatment. But what does it mean for people with the disease?

Published

1 year ago

July 19, 2023

Trial results of a new drug to treat Alzheimer’s disease, donanemab, shows it can slow cognitive decline by 35%. The drug has been hailed as a “turning point” in Alzheimer’s treatment.

But as usual, there’s more to the story. The study only included people with early or mild disease, not more advanced symptoms. Donanemab is not a cure for Alzheimer’s. Nor is it 100% safe.

So what did the trial actually find? And how might this drug affect the lives of people with Alzheimer’s disease?

What is Alzheimer’s disease?

There are more than 100 types of dementia, but Alzheimer’s disease is the most common, accounting for around 70% of cases.

The disease is caused by the accumulation of two proteins: amyloid and tau. Amyloid can accumulate for at least 20 years prior to the onset of symptoms, forming clumps in the brain.

Once symptoms have started and are progressing, tau, a marker of cell damage, also begins to accumulate.

Clinical symptoms progress, on average, over seven to ten years after diagnosis. But in Australia, there is a lag of up to three years from the point at which people first develop symptoms before a diagnosis is typically made.

What have drug treatments aimed to do?

The “amyloid hypothesis”, which suggests amyloid is the key cause of the disease, has driven Alzheimer’s research for more than 25 years.

Multiple drugs targeting amyloid have, however, failed in clinical trials over most of that period, casting doubt on the validity of amyloid as a target – until recently.

Our bodies produce antibodies in response to the presence of a foreign invader such as a bacteria or virus. Mimicking the approach taken by our immune systems, scientists have developed antibodies in the lab that recognise amyloid as such an invader.

Specifically targeting amyloid, these drugs are known as monoclonal antibodies. Donanemab is one of three monoclonal antibodies targeting amyloid that have shown various degrees of success in clinical trials in slowing decline in people with early stage disease.

OK so what did the donanemab trial find?

The manufacturer’s clinical trial included 1,736 patients with very mild memory loss due to Alzheimer’s disease, and with early clinical Alzheimer’s disease.

Half received donanemab by intravenous infusion over an 18-month study, the remainder were treated with a placebo (a “dummy” version).

The results were analysed by dividing the study population into two further groups: those with low to intermediate levels of tau; and those with high tau levels (high tau correlates with the presence of more advanced brain cell damage).

Those with low and intermediate tau declined by 35% less than those treated with placebo. About half of the treatment group cleared amyloid from their brains below the threshold used to diagnose the disease, over 12 months of treatment.

The high tau group did far less well.

People may be delaying diagnosis because they think nothing can be done.
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Participants aged under 75 and those showing only mild cognitive impairment (rather than the full clinical picture of Alzheimer’s disease) had their progression slowed by around 50% over the same period.

Patients were assessed using both cognitive measures and measures of daily function, such as the ability to do personal and household tasks. The results translated into the treatment group showing levels of decline at 18 months that were experienced by the placebo group at 10.5 to 13.6 months, depending on the participant subgroup studied.

Important examples may be that they continue to be able to drive, pay bills, or attend activities outside of the home independently.

But both the treatment and the placebo groups declined overall. In other words, it doesn’t stop the decline, it slows it, in people

What are the downsides?

At least two patients in the trial died from complications of brain swelling caused by donanemab. Around one-quarter of the treatment group showed some degree of swelling, most of which didn’t cause symptoms.

Two patients in the study died from complications from brain swelling.
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The cost of donanemab will be significant, at US$26,500 or around A$39,000 per year.

Donanemab has already been approved by the US Food and Drug Administration.
Eli Lilly, the drug’s manufacturer, has applied to the Therapeutic Goods Administration (TGA) for approval for use in Australia.

But TGA approval is only the first step to making the drug available here. A further assessment will determine whether the Pharmaceutical Benefits Scheme subsidises the drug to make it affordable.

It’s likely any PBS listing would restrict the drug’s use to people whose disease state mirrors that of those included in the clinical trial population – people with early symptoms, who have had PET scans showing the presence of amyloid (and low and intermediate tau).

This is not a drug for everyone with Alzheimer’s disease.

Preparing for early detection and treatment

People have tended to delay seeking assessment of their memory symptoms because “nothing can be done anyway”. GPs may have been reluctant to refer to other specialists for assessment for the same reason.

The potential for early treatment means this needs to change. We also need to develop our diagnostic and treatment infrastructure (building the necessary PET scanners and infusion centres) that will be necessary to facilitate timely diagnosis and treatment when the drug does become available locally.

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Health

Canada to donate up to 200,000 vaccine doses to combat mpox outbreaks in Africa

Published

24 hours ago

September 13, 2024

Anne Joseph

The Canadian government says it will donate up to 200,000 vaccine doses to fight the mpox outbreak in Congo and other African countries.

It says the donated doses of Imvamune will come from Canada’s existing supply and will not affect the country’s preparedness for mpox cases in this country.

Minister of Health Mark Holland says the donation “will help to protect those in the most affected regions of Africa and will help prevent further spread of the virus.”

Dr. Madhukar Pai, Canada research chair in epidemiology and global health, says although the donation is welcome, it is a very small portion of the estimated 10 million vaccine doses needed to control the outbreak.

Vaccine donations from wealthier countries have only recently started arriving in Africa, almost a month after the World Health Organization declared the mpox outbreak a public health emergency of international concern.

A few days after the declaration in August, Global Affairs Canada announced a contribution of $1 million for mpox surveillance, diagnostic tools, research and community awareness in Africa.

On Thursday, the Africa Centres for Disease Control and Prevention said mpox is still on the rise and that testing rates are “insufficient” across the continent.

Jason Kindrachuk, Canada research chair in emerging viruses at the University of Manitoba, said donating vaccines, in addition to supporting surveillance and diagnostic tests, is “massively important.”

But Kindrachuk, who has worked on the ground in Congo during the epidemic, also said that the international response to the mpox outbreak is “better late than never (but) better never late.”

“It would have been fantastic for us globally to not be in this position by having provided doses a much, much longer time prior than when we are,” he said, noting that the outbreak of clade I mpox in Congo started in early 2023.

Clade II mpox, endemic in regions of West Africa, came to the world’s attention even earlier — in 2022 — as that strain of virus spread to other countries, including Canada.

Two doses are recommended for mpox vaccination, so the donation may only benefit 100,000 people, Pai said.

Pai questioned whether Canada is contributing enough, as the federal government hasn’t said what percentage of its mpox vaccine stockpile it is donating.

“Small donations are simply not going to help end this crisis. We need to show greater solidarity and support,” he said in an email.

“That is the biggest lesson from the COVID-19 pandemic — our collective safety is tied with that of other nations.”

This report by The Canadian Press was first published Sept. 13, 2024.

Canadian Press health coverage receives support through a partnership with the Canadian Medical Association. CP is solely responsible for this content.

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Health

How many Nova Scotians are on the doctor wait-list? Number hit 160,000 in June

Published

2 days ago

September 11, 2024

Anne Joseph

HALIFAX – The Nova Scotia government says it could be months before it reveals how many people are on the wait-list for a family doctor.

The head of the province’s health authority told reporters Wednesday that the government won’t release updated data until the 160,000 people who were on the wait-list in June are contacted to verify whether they still need primary care.

Karen Oldfield said Nova Scotia Health is working on validating the primary care wait-list data before posting new numbers, and that work may take a matter of months. The most recent public wait-list figures are from June 1, when 160,234 people, or about 16 per cent of the population, were on it.

“It’s going to take time to make 160,000 calls,” Oldfield said. “We are not talking weeks, we are talking months.”

The interim CEO and president of Nova Scotia Health said people on the list are being asked where they live, whether they still need a family doctor, and to give an update on their health.

A spokesperson with the province’s Health Department says the government and its health authority are “working hard” to turn the wait-list registry into a useful tool, adding that the data will be shared once it is validated.

Nova Scotia’s NDP are calling on Premier Tim Houston to immediately release statistics on how many people are looking for a family doctor. On Tuesday, the NDP introduced a bill that would require the health minister to make the number public every month.

“It is unacceptable for the list to be more than three months out of date,” NDP Leader Claudia Chender said Tuesday.

Chender said releasing this data regularly is vital so Nova Scotians can track the government’s progress on its main 2021 campaign promise: fixing health care.

The number of people in need of a family doctor has more than doubled between the 2021 summer election campaign and June 2024. Since September 2021 about 300 doctors have been added to the provincial health system, the Health Department said.

“We’ll know if Tim Houston is keeping his 2021 election promise to fix health care when Nova Scotians are attached to primary care,” Chender said.

This report by The Canadian Press was first published Sept. 11, 2024.

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Health

Newfoundland and Labrador monitoring rise in whooping cough cases: medical officer

Published

3 days ago

September 10, 2024

Anne Joseph

ST. JOHN’S, N.L. – Newfoundland and Labrador‘s chief medical officer is monitoring the rise of whooping cough infections across the province as cases of the highly contagious disease continue to grow across Canada.

Dr. Janice Fitzgerald says that so far this year, the province has recorded 230 confirmed cases of the vaccine-preventable respiratory tract infection, also known as pertussis.

Late last month, Quebec reported more than 11,000 cases during the same time period, while Ontario counted 470 cases, well above the five-year average of 98. In Quebec, the majority of patients are between the ages of 10 and 14.

Meanwhile, New Brunswick has declared a whooping cough outbreak across the province. A total of 141 cases were reported by last month, exceeding the five-year average of 34.

The disease can lead to severe complications among vulnerable populations including infants, who are at the highest risk of suffering from complications like pneumonia and seizures. Symptoms may start with a runny nose, mild fever and cough, then progress to severe coughing accompanied by a distinctive “whooping” sound during inhalation.

“The public, especially pregnant people and those in close contact with infants, are encouraged to be aware of symptoms related to pertussis and to ensure vaccinations are up to date,” Newfoundland and Labrador’s Health Department said in a statement.

Whooping cough can be treated with antibiotics, but vaccination is the most effective way to control the spread of the disease. As a result, the province has expanded immunization efforts this school year. While booster doses are already offered in Grade 9, the vaccine is now being offered to Grade 8 students as well.

Public health officials say whooping cough is a cyclical disease that increases every two to five or six years.

Meanwhile, New Brunswick’s acting chief medical officer of health expects the current case count to get worse before tapering off.

A rise in whooping cough cases has also been reported in the United States and elsewhere. The Pan American Health Organization issued an alert in July encouraging countries to ramp up their surveillance and vaccination coverage.

This report by The Canadian Press was first published Sept. 10, 2024.

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