Eisai and Biogen, Leqembi manufacturer, receive FDA approval for Alzheimer's drug

• The FDA approval includes a box label warning about the drug's known side effects, which include brain swelling and tiny bleeds.
• Lecanemab is the first amyloid-targeting drug to gain full FDA approval.
• The FDA approval is expected to trigger Medicare coverage for the $26,500-a-year drug.

The Food and Drug Administration on Thursday approved the drug lecanemab for people with early Alzheimer's disease, making it easier for older adults to get the first drug proven to slow memory and thinking problems.

The decision was closely watched by patient advocates and scientists alike because Eisai and Biogen's drug, sold under the brand name Leqembi, is the first beta amyloid-targeting medication to pass the FDA's full review. The approval also is expected to trigger Medicare coverage for adults over 65 who have been unable to afford the $26,500-a-year drug. More than 6 million Americans live with Alzheimer's disease, the fifth-leading cause of death for adults over 65.

The drug works by clearing beta amyloid, a protein the accumulates in the brains of Alzheimer's patients. Drug companies have pursued amyloid-targeting drugs for two decades on the theory that removing clumps of the protein from the brain could delay or halt memory and thinking problems. Eisai said its study showed people administered a biweekly infusion of the drug declined 27% more slowly than a placebo group.

Ivan Cheung, the Americas region chairman and CEO of Tokyo, Japan-based Eisai, said the FDA approval of Leqembi is a "triumph for the Alzheimer's disease community" because it's the first medication to slow the progression of the disease.

"With Leqembi, patients can get more time." Cheung told USA TODAY. "They can get more time in a more mild stage of the disease. So whatever they're doing now, they can keep doing it for longer."

FDA bolsters safety warnings

The FDA will require a boxed warning about the drug's known side effects, which include brain swelling and tiny bleeds. These side effects, called amyloid-related imaging abnormalities, occur in some patients who take Leqembi or other amyloid-targeting drugs. While most patients won't notice symptoms that typically surface early during treatment, some experience headaches or infusion-related reactions such as fever, chills or stomach discomfort. The safety language warns "serious and life-threatening events rarely can occur," including strokes.

The safety language notes patients who inherited two copies of the Alzheimer's risk gene ApoE4 are at greater risk of swelling and brain bleeds. About 15% of patients who take the medication have two copies or this susceptibility gene. The safety warning said patients should take a genetic test to learn about their ApoE4 status before starting treatment. The FDA also recommends doctors discuss genetic testing with patients. If patients decline testing, doctors won't know if they face a greater genetic risk of brain swelling and bleeding.

Doctors also should be cautious when prescribing the drug to patients on blood thinners, the FDA said.

Before starting the drug, doctors must confirm a patient has amyloid in the brain, which can be detected by a PET scan or a spinal tap. Patients also must get multiple MRIs during the first year of treatment to check for side effects.

Improved access

Dr. James Galvin, a neurologist and director of the comprehensive center for brain health at the University of Miami Health System, said the FDA's approval should make the drug easier to get for patients with early Alzheimer's disease.

Doctors have prescribed Leqembi since January, when the FDA granted fast-track approval. But the Centers for Medicare and Medicaid Services has refused to pay for Leqembi, Biogen's Aduhelm and other similar Alzheimer's drugs that get FDA's "accelerated approval" unless patients are enrolled in a clinical trial.

The FDA's full approval means Medicare will pay for the drug as long as prescribing doctors participate in a registry, or a database that tracks how well the drug works. Medicare said such registries are used to learn how patients fare after taking newly approved drugs or undergoing procedures.

The drug has been limited mainly to people who can afford the full price or have qualified for a clinical trial. If Medicare extends coverage following FDA's approval, "this really changes access of the medication to a wide group of people," Galvin said.

Advocates hail FDA move

The Alzheimer's Association has pushed for Medicare to cover Leqembi and other similar Alzheimer's drugs should they gain FDA approval.

Joanne Pike, Alzheimer’s Association president and CEO, said the FDA's approval means patients can access a drug that "can give people in the early stages of Alzheimer’s more time to maintain their independence and do the things they love."

“This gives people more months of recognizing their spouse, children and grandchildren," Pike said. " This also means more time for a person to drive safely, accurately and promptly take care of family finances, and participate fully in hobbies and interests.”

Dr. Alvaro Pascual-Leone, a professor of neurology at Harvard Medical School, said Leqembi's approval is a "major catalyst for change" for how the doctors care for dementia patients. However, he said other treatments now being developed attack Alzheimer's disease in other ways, such as targeting tau tangles also found in brain neurons. He added other studies show lifestyle changes can slow cognitive decline.

"Ultimately, a multipronged therapeutic approach that incorporates behavioral modifications in addition to drugs is going to be most effective," said Pascual-Leone, also a chief medical officer of Linus Health, a cognitive testing provider.

Ken Alltucker is on Twitter at @kalltucker, or can be emailed at alltuck@usatoday.com.