U.S. health officials on Friday approved a closely watched Alzheimer's drug that modestly slows the brain-robbing disease, albeit with potential safety risks that patients and their doctors will have to carefully weigh. The drug, Leqembi, is the first that's been convincingly shown to slow the decline in memory and thinking that defines Alzheimer's by targeting the disease's underlying biology. The Food and Drug Administration approved it for patients with mild or early-stage Alzheimer's who test positive for a key hallmark of the disease — the buildup of plaque in the brain. Leqembi, from Japan's Eisai and its U.S. partner Biogen, is a rare success in a field accustomed to failed experimental treatments for the incurable condition. The delay in cognitive decline brought about by the drug likely amounts to just several months, but Dr. Joy Snider and some other experts say it could still meaningfully improve people's lives. "This drug is not a cure. It doesn't stop people from getting worse, but it does measurably slow the progression of the disease," said Snider, a neurologist at Washington University in St. Louis. "That might mean someone could have an extra six months to a year of being able to drive." Snider stressed that the medicine, pronounced "leh-KEM-bee," comes with downsides, including the need for twice-a-month infusions and possible side effects like brain swelling. "The patients at greatest risk for the bleeding during treatment with Lecanemab are those who are on blood thinners or medicines that are used to prevent stroke," said Dr. Sam Gandy at Mount Sinai Hospital. The FDA approval came via its accelerated pathway, which allows drugs to launch based on early results, before they're confirmed to benefit patients. The agency's use of that shortcut approach has come under increasing scrutiny from government watchdogs and congressional investigators.