What to know about the Alzheimer's drug just given full FDA approval

In a positive step forward for Alzheimer's disease treatment, the Food and Drug Administration on Thursday evening granted full approval for a new drug called Leqembi.

Leqembi is the first drug of its kind with clear evidence it can slow cognitive decline in people with early stages of the disease.

The full approval means Medicare can start covering the cost of treatment for patients, making it more widely available.

"This treatment, while not a cure, can give people in the early stages of Alzheimer's more time to maintain their independence and do the things they love," said Joanne Pike, CEO and president of the Alzheimer's Association, in a statement. "This gives people more months of recognizing their spouse, children and grandchildren."

"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," the statement continued.

Here's a brief look at what you need to know about Leqembi.

What is Alzheimer's disease?

More than six million Americans are living with Alzheimer's in 2023, according to the Alzheimer's Association, which further says that by 2050, this number is projected to rise to almost 13 million.

It's unclear what causes Alzheimer's but the National Institute on Aging says it's likely a combination of age-related changes in the brain coupled with genetic, environmental or lifestyle factors.

Patients diagnosed with the disease suffer a decline in several areas, including cognitive, behavioral and physical abilities.

There is currently no cure for Alzheimer's, and one in three seniors dies with the disease or another form of dementia, according to the Alzheimer's Association.

How does Leqembi work?

The drug, generically known as lecanemab and manufactured by the pharmaceutical companies Eisai and Biogen, targets amyloid beta, the main component of amyloid plaques -- abnormal, insoluble clusters of protein fragments -- found in the brains of people with Alzheimer's disease.

Leqembi is administered intravenously every two weeks. It marks the plaques to be cleared by the immune system before they can smother neurons in the brain.

However, officials have stressed that the drug is a treatment, not a cure.

In November 2022, data from a phase III clinical trial showed Leqembi slowed the rate of cognitive decline by 27% in patients experiencing the early stages of Alzheimer's, making the drug the first of its kind to produce such a positive trial result.

The FDA granted accelerated approval in January 2022 before the full approval that was granted this week. However, the drug will only be given to people in the early stages of Alzheimer's, not those who already have significant cognitive impairment.

Are there concerns about Leqembi?

Studies have shown that that there is some risk of swelling and bleeding in the brain with Leqembi, though less so than with Aduhelm, another Alzheimer's drug that the FDA approved in 2021.

However, a congressional report found that Aduhlem's approval by the FDA was "rife with irregularities," and that the agency's actions "raise serious concerns about FDA's lapses in protocol."

Additionally, for those not on Medicaid, there is a concern about how available Leqembi will be due to its cost. Eisai and Biogen have said Leqembi is priced at over $26,000 per year.