The Food and Drug Administration (FDA) on Thursday gave full approval to Leqembi, the first drug that can change the course of Alzheimer's disease. The move gives patients a glimmer of hope, and patient advocates and some doctors say it's the beginning of a new era of Alzheimer's treatment.
But there are lingering questions about the drug's safety, cost, effectiveness and accessibility.
Here are five things to know:
Leqembi is meant only for people in the very early stages of Alzheimer's disease
Alzheimer's disease affects more than 6 million Americans. Scientists have been searching for an effective treatment for decades and still don't know what causes the disease, which is ultimately 100 percent fatal.
Leqembi, developed by Eisai and Biogen, is a breakthrough. But the impact is very modest. It's not a cure and doesn't restore memories of people afflicted with the disease.
It was only approved for patients with mild cognitive impairment or mild dementia, who have a confirmed presence of brain plaque called amyloid.
"It's a major step. And it's going to change how we practice and how we diagnose," University of Kansas Medical Center neurologist Jeffrey Burns said. "But I see it as a first step with a lot of steps hopefully to come, with new drugs and new approaches."
Late-stage trial data showed that the drug slowed cognitive decline by about 27 percent over 18 months compared to a placebo. But the difference between patients receiving the drug and the placebo was small, and some critics say it wasn't clinically significant.
Supporters argue that for the patients who benefit, the drug could stave off memory loss long enough to buy them a few extra months with family and loved ones.
Leqembi's approval will unfortunately not help patients who are already past the early stages of the disease.
Leqembi is expensive. Medicare will cover it, with caveats.
The FDA's approval opens up Leqembi to a much wider population, because Medicare said it will cover the $26,500 annual cost.
After the FDA gave Leqembi accelerated approval in January, Medicare said it was limiting coverage to clinical trials only. Now, Medicare will broadly cover it, so long as patients and providers participate in data collection registries that will track how the drug performs in real-world settings.
Industry groups, patient advocates and bipartisan lawmakers have been lobbying against the use of a registry, arguing it will prevent people who could benefit from accessing the drug. Registries are used for some medical devices, but never for an FDA-approved drug.
Regardless of the registry requirement, patients could also face thousands of dollars a year in co-insurance. Leqembi is an infusion drug, meaning that without supplemental coverage, enrollees are responsible for 20 percent of the cost after meeting a deductible.
Patients may also be responsible for potentially tens of thousands of dollars of additional costs beyond the drug itself. It's unclear if Medicare will pay for the cost of the medical visit or the regular brain scans needed to monitor a patient's progress.
There are risks in taking it
The positive outcomes of Leqembi are tempered by a potentially serious type of brain swelling or bleeding.
The condition, called amyloid-related imaging abnormalities (ARIA), is usually asymptomatic and managed safely, but there have been serious and even fatal cases. Three patient deaths during the trial were thought to be linked to the drug.
Nearly 13 percent of patients receiving Leqembi in a large clinical trial experienced brain swelling, compared to 2 percent on placebo, but most of those cases were mild or moderate. About 17 percent of the patients experienced brain bleeding, compared with 9 percent of patients receiving the placebo.
FDA included a "boxed warning" on the drug's label to highlight the safety issues.
Patients who are at higher risk of ARIA include those on blood thinners. The FDA recommended caution for clinicians who may consider prescribing Leqembi for those patients but did not advise against it.
The agency also said patients with two copies of a gene mutation linked to Alzheimer's have a considerably higher risk of complications. The FDA recommended genetic testing, but did not require it.
There are barriers to widespread uptake
Experts largely agree that the U.S. health system isn't equipped to diagnose and treat large numbers of Alzheimer's patients.
Getting the drug to everyone who qualifies for it and wants it "is not something we're going to be able to do overnight," Burns said.
"Memory clinics around the country are backed up without this drug. I don't know how fast the demand will increase, but it's going to increase for memory clinics and really stretch us even further," he said.
To even be eligible for Leqembi, patients need complex imaging or a spinal tap to confirm the presence of amyloid in the brain. Once prescribed, they need to travel to get infusions every other week, as well as regular brain scans for monitoring.
Large academic medical centers are likely the best equipped to handle those patients, which could be a barrier to rural patients. And even the capable medical centers will likely experience a bottleneck of patients because of a shortage of qualified specialists.
A similar drug is on the horizon
There could be another anti-amyloid drug on the market soon.
Eli Lilly in May released promising initial results from a clinical trial of its new Alzheimer’s antibody treatment that were comparable to Leqembi.
The company is expected to release more detailed data later this month, and the FDA could approve it by the end of the year.
Leqembi is the second anti-amyloid drug to hit the market, but its predecessor was the controversial Aduhelm.
The FDA granted accelerated approval to Aduhelm in 2021, despite a recommendation from its outside panel of experts not to.
The data on Aduhelm was conflicting and contradictory; while it appeared to remove plaque from the brain, it did not seem to slow the progression of the disease. As a result, Medicare refused to cover the drug, and doctors wouldn't prescribe it.
