On Alzheimer's, an Advance 'We've All Been Waiting For'

Last summer, the Food and Drug Administration gave the thumbs-up to Leqembi, the first drug shown to slow the progression of Alzheimer's disease. Now, almost a year to the day after that move, the government agency has greenlit a second drug: Eli Lilly's donanemab, sold under the brand name Kisunla, was given the OK on Tuesday, for mild or early dementia cases spurred by Alzheimer's, reports the AP.

• How it works: Kisunla clears out the protein amyloid, which has been found to cluster together to form plaques in the brains of Alzheimer's patients years before symptoms even appear, per the New York Times.
• Results: The FDA approved Kisunla after an 18-month clinical trial in which patients with mild dementia or mild cognitive impairment who received the drug saw their cognitive decline slow by up to 7.5 months more than those who received a placebo.

• Advantages: Patients need to take Kisunla via IV infusion just once a month (Leqembi is needed twice a month), and they can stop taking it once their plaque levels dip to low-enough numbers. In this study, almost half of the subjects got to that point within a year's time.
• Warnings: The researchers note that Kisunla does pose a risk of amyloid-related imaging abnormalities, or ARIA, which most commonly manifest as temporary swellings on the brain. Per an Eli Lilly release, ARIA "is a common side effect that does not usually cause any symptoms, but serious symptoms can occur," and may even prove fatal; three patients in the trial died as a result. The AP notes that such brain swelling and bleeding are common side effects in drugs that target plaque.
• Cost: The Washington Post notes a six-month supply of Kisunla would cost about $12,500, while a year's worth of therapy would run around $32,000. The paper adds that many patients won't pay the full cost, though, since Medicare may pick up some of the slack for certain individuals. Leqembi costs $26,000 for a year's supply, but patients need to keep taking it even after the amyloid protein is cleared.
• Reaction: Some experts are skeptical on Kisunla's powers, noting the risks may outweigh the benefits. Others say, however, that the modest benefits offered may still be worth it—"for example, by delaying progression from mild forgetfulness to having to be reminded about appointments," per the Times. "Having multiple treatment options is the kind of advancement we've all been waiting for—all of us who have been touched, even blindsided, by this difficult and devastating disease," says Joanne Pike, head of the Alzheimer's Association, in a statement, per the Post.

(More Alzheimer's disease stories.)