U.S. FDA approves new Alzheimer's drug Leqembi

The U.S. Food and Drug Administration (FDA) on Thursday fully approved Leqembi, the first medicine shown to slow the progression of Alzheimer's disease.

The FDA said the approval was based on clinical data showing the drug's effect on a "surrogate endpoint" that is "reasonably likely to predict a clinical benefit to patients."

Leqembi slows cognitive decline by about 27% over 18 months, according to the clinical trial.

"Today's action is the first verification that a drug targeting the underlying disease process of Alzheimer's disease has shown clinical benefit in this devastating disease," Teresa Buracchio, acting director of the Office of Neuroscience in the FDA's Center for Drug Evaluation and Research, said in the statement.

"This confirmatory study verified that it is a safe and effective treatment for patients with Alzheimer's disease," Buracchio added.

The agency's approval is likely to trigger Medicare coverage for adults over 65 as the twice-monthly infusion costs $26,500 annually.

More than 6.5 million Americans are affected by Alzheimer's disease, which is the fifth-leading cause of death among adults over 65.