The drug Lecanemab has received full approval from the U.S. Food and Drug Administration (FDA) on the 6th of July 2023

This is the first treatment to receive full approval from the agency to help slow the progression of Alzheimer’s disease.

Prof Ralph Martins AO, Director of Research at the Australian Alzheimer’s Research Foundation, said it was an exciting development. “This is one of the first disease-modifying drug that we think will change the lives of a number of patients,” he said.

“The drug has been shown to effectively remove amyloid from the brain,” Prof Martins said. “It not only brings down the amyloid but also slows down the progression of the disease in terms of the cognitive decline by as much as 27%.” This 27 percent decline in disease progression occurred over an 18-month period in the Phase 3 clinical trial.

Another way to look at it would be to say if you took the drug for two years, you could be up to nine months better off.

It has been almost two decades since a new treatment for the disease has received traditional approval, following accelerated approval being granted by the FDA to Biogen’s Aducanumab (Aduhelm) in 2021, highlighting the critical need for a treatment.

The treatment works by targeting and breaking down amyloid-beta plaques, a hallmark in the Alzheimer’s brain.

The Australian Alzheimer’s Research Foundation is taking part in the clinical trials using Lecanemab. The Phase 3 ClarityAD study for mild Alzheimer’s disease was the study that provided the data for the Lecanemab FDA submission. The AHEAD3-45 study is targeting a preclinical Alzheimer’s disease population, i.e. those without symptoms but with risk factors.

The FDA is considered the ‘gold standard’ for approval of new drugs. Lecanemab was approved in January under the FDA’s Accelerated Approval pathway utilising data obtained from the Phase 2 clinical trial data. Phase 3 clinical trial data from the ClarityAD study was submitted to the FDA on completion of the study in early 2023 and has led to full FDA approval being granted.
Teresa Buracchio, acting director of the Office of Neuroscience in the FDA’s Center for Drug Evaluation and Research, said, “This confirmatory study verified that it is a safe and effective treatment for patients with Alzheimer’s disease.”

‘Not a magic bullet’

Lecanemab doesn’t cure Alzheimer’s disease. Patients will still decline — but not as quickly. For certain patients who are still in the early stages of the disease, the drug appears to slow the loss of cognitive function.

Prof Martins stressed that early detection of Alzheimer’s was very important.

“It’s not a magic bullet. It may not benefit everyone with Alzheimer’s disease. This drug is designed to look at people in the early stages of Alzheimer’s disease. The message is, that the earlier we get in, the more effective these treatments are going to be.”

What does this mean for Australians?

Lecanemab has only been approved by the FDA for use within the United States.

Before it is available to the general population in Australia, it will need to be approved for use by the Therapeutic Goods Administration (TGA).  

The drug is administered via intravenous infusion once a fortnight. It has potential side effects including bleeding and swelling on the brain, particularly in people who have the ApoE e4 gene.

Prof Martins said the possible side effects needed to be carefully monitored by health professionals, and by using MRI brain imaging techniques.

On June 30 Australia’s Therapeutic Goods Administration (TGA) accepted and commenced evaluating an application to register the use of Lecanemab in Australia.

The legislated time frame for TGA assessment is 255 working days for applications of this kind but time frames for evaluation of individual applications ultimately depend on when all data is provided by the sponsor.

The TGA’s assessment will consider the risks and benefits of the treatment and will ensure that the data meets its standards of safety, quality and efficacy.