New Alzheimer’s Drug Gets FDA Green Light

The FDA’s decision was based on phase 2 clinical trial data, which showed that participants in the early stages of Alzheimer’s disease who received lecanemab had a “statistically significant reduction in brain amyloid plaque” compared to those who received a placebo over the course of the study period. 

Results from a phase 3 trial, which were published after lecanemab’s manufacturers applied for accelerated approval, support the initial findings. In a study of nearly 1,800 adults between the ages of 50 and 90 with early Alzheimer’s, participants who received lecanemab saw a reduction in amyloid levels over 18 months. What’s more, the drug was associated with “moderately less decline on measures of cognition and function” compared to the placebo, though some Alzheimer’s experts have questioned whether it’s enough to show a true benefit to patients.

The prescribing information for lecanemab includes a warning for amyloid-related imaging abnormalities, which can include swelling and bleeding in the brain. Common side effects of the drug include infusion-related reactions (this may include flu-like symptoms, nausea, vomiting and changes in blood pressure) and headache.

The FDA said in its decision that the drug is not for all Alzheimer’s patients, just those whose disease has progressed only to mild cognitive impairment or mild dementia, matching the population studied in the trials. 

Will the drug be covered?

It’s unclear how many people could potentially benefit from lecanemab, which will cost $26,500 per year, its makers said in a news release. In April 2022, the Centers for Medicare & Medicaid Services (CMS) issued a national policy for coverage of Aduhelm, which is also a monoclonal antibody that goes after amyloid, and other drugs like it. 

In its decision, CMS said it will cover monoclonal antibodies that target amyloid for the treatment of Alzheimer’s disease that receive traditional approval from the FDA, but it will restrict coverage for those granted accelerated approval to beneficiaries enrolled in approved clinical trials. In a statement released Jan. 6 after the FDA’s decision, CMS said it is “examining available information and may reconsider its current coverage based on this review.”

The companies behind lecanemab ­­— Eisai and Biogen — have indicated they plan to seek full FDA approval using the recently published phase 3 data. 

Meanwhile, the FDA declined to grant accelerated approval to an experimental Alzheimer’s drug from Eli Lilly, also an amyloid-targeting monoclonal antibody, based on phase 2 clinical trial data. In a Jan. 19 news release, the company said the FDA has requested data from "at least 100 patients who received a minimum of 12 months of continued treatment" on the drug, known as donanemab. The company is studying the drug in a late-stage trial, after which it plans to seek FDA approval.

Anti-amyloid therapies are one avenue scientists are pursuing for the treatment of Alzheimer’s disease, which without intervention is expected to affect some 14 million Americans by 2060, according to the Centers for Disease Control and Prevention. Other areas of research focus on keeping tau proteins from tangling — another hallmark of Alzheimer’s — and reducing inflammation, also a driver of the disease. And many Alzheimer’s experts say treating the disease will likely require more than one approach.

At the same time, research surrounding Alzheimer’s prevention is picking up speed. Recent studies show that adopting certain habits — such as controlling high blood pressure, staying physically active, avoiding excessive drinking, and preventing or treating hearing loss — can help reduce the risk of Alzheimer’s and related dementias. In fact, it’s estimated that 40 percent of dementia cases can be attributed to 12 modifiable risk factors.

Editor’s note: This story, originally published  Jan. 6, 2023, has been updated to reflect new information.