Aducanumab: US regulators approve first new Alzheimer's drug in almost 20 years
US regulators have approved the first new Alzheimer's drug in almost 20 years.
The Food and Drug Administration (FDA) approved aducanumab - against the advice of their own outside experts.
The antibody drug, developed by pharmaceutical company Biogen, is the first to work by tackling brain changes that cause the disease, rather than just the symptoms.
It’s the only drug that US regulators have said can likely treat the underlying disease, rather than manage symptoms like anxiety and insomnia.
Independent advisors have warned, however, that the much-debated treatment hasn’t been shown to help slow the brain-destroying disease.
Aducanumab cannot cure or reverse Alzheimer's, but Biogen claims the drug modestly slows the rate of decline. Current drugs only temporarily ease symptoms and no new options have emerged since 2003.
More than five million people in the United States and many more worldwide have Alzheimer’s, the most common form of dementia.
A green light from the FDA may pave the way for it to be used in the UK.
In March 2020, Biogen announced it would stop its two phase-III trials of aducanumab early. An initial assessment suggested that the trials were unlikely to substantially improve people’s memory and thinking by the end of the trial. However, Biogen carried out a new analysis involving additional data.
It said the findings show aducanumab not only reduces amyloid - the protein fragments linked to the disease - but it can also slow the decline of memory and thinking skills.
The FDA’s top drug regulator acknowledged that "residual uncertainties" surround the drug, but said Aduhelm’s ability to reduce harmful clumps of plaque in the brain "is expected" to help slow dementia.
Why are there uncertainties about the drug?
In a trial of the drug, p atients taking aducanumab saw their thinking skills decline 22% more slowly than patients taking a sham treatment.
But that meant a difference of just 0.39 on an 18-point score of cognitive and functional ability.
It’s also unclear how such metrics translate into practical benefits, like greater independence or ability to recall important details.
The drug received a scathing assessment in November by the FDA's independent group of neurological experts.
The group voted "no" to a series of questions on whether reanalysed data from a single study submitted by Biogen showed that the drug was effective.
But the FDA isn’t required to follow the advice of its outside panelists and has previously disregarded their input when making similarly high-profile drug decisions.