However, the decision is not without controversy.
The drug, aducanumab, which will be marketed as Aduhelm, has been shown to reduce levels of beta-amyloid, the sticky plaque that is the hallmark of Alzheimer’s disease, in the brain.
However, studies have not been able to show the drug slows declines in memory and thinking, and in fact two large recent studies have had opposite findings.
In November, a panel of FDA advisers recommended the agency do not approve the drug.
A condition of the approval is that Biogen, the company that makes the drug, conducts further research to confirm the reduction of amyloid plaques does in fact cause clinical improvements for patients.
These studies could take several years, and if they fail to show aducanumab causes an improvement, the approval may be withdrawn. In the meantime, aducanumab will be available for sale in the United States.
Some have voiced concerns Biogan may have trouble recruiting enough people to take part in the trial, because with the drug now available, potential participants may not want to risk getting the placebo.
The drug will be administered through monthly infusions. Anyone taking the drug will need to have regular brain scans in order to detect a rare side effect: bleeding or swelling in the brain.
The FDA approved the drug through its ‘accelerated approval pathway’, a fast-track approval process designed to hasten access to drugs that could provide a “meaningful therapeutic advantage” over existing treatments for patients with serious or life-threatening diseases, and where a clinical benefit is “expected” – even if there is still uncertainty about the benefit.
The drug will be administered through monthly infusions. Anyone taking the drug will need to have regular brain scans in order to detect a rare side effect: bleeding or swelling in the brain.
High hopes
Dementia Australia said the approval was “exciting news” for the global dementia community.
The drug is currently under review by Australia’s Therapeutic Goods Administration (TGA), with a decision expected in early 2022.
Dementia Australia Honorary Medical Advisor, Associate Professor Michael Woodward AM, said though there is no cure for Alzheimer’s disease, a drug that can remove the amyloid proteins is a significant step forward.
“We can’t bring back brain tissue that has been damaged irreversibly but we can protect brain tissue by removing the toxic effects of this amyloid,” Woodward said.
“The original trials were terminated when it looked like the drug wasn’t working – at that stage there weren’t many people on the highest dose of the drug.
“When researchers examined more data that included more people who had been, for longer periods, on the highest dose, they demonstrated a significant effect.
One hundred Australians took part in the US aducanumab trials.
“I applaud them and all trial participants for their contribution to this research,” said McCabe.
Drug gives hope to millions
In a statement, the FDA said, “Alzheimer’s is an irreversible, progressive brain disorder that slowly destroys memory and thinking skills, and eventually, the ability to carry out simple tasks.
“While the specific causes of Alzheimer’s disease are not fully known, it is characterised by changes in the brain – including amyloid plaque – that result in loss of neurons and their connections.
“These changes affect a person’s ability to remember and think.”
Patrizia Cavazzoni, MD, director of the FDA’s Center for Drug Evaluation and Research, said, “Alzheimer’s disease is a devastating illness that can have a profound impact on the lives of people diagnosed with the disease as well as their loved ones.
“Currently available therapies only treat symptoms of the disease; this treatment option is the first therapy to target and affect the underlying disease process of Alzheimer’s.”
The US Alzheimer’s Association “enthusiastically” welcomed the news.
“This approval is a victory for people living with Alzheimer’s and their families,” said Harry Johns, Alzheimer’s Association President and Chief Executive Officer.
“This therapy will be of great interest to many.”
Worldwide, 44 million people are believed to be living with Alzheimer’s disease.