What to Know About Aduhelm, the New Alzheimer's Drug

The drug, given intravenously once a month, signals the immune system to break down amyloid plaques, protein clumps in the brain thought to kill brain cells. In theory, clearing amyloid could slow brain deterioration, though other experimental treatments targeting amyloid haven’t eased Alzheimer’s symptoms.

That’s uncertain because the two pivotal clinical trials of Aduhelm yielded conflicting results. On average, study participants—people with very mild symptoms of Alzheimer’s disease—scored worse on assessments of memory, problem-solving skills, and function after taking Aduhelm or a placebo for 18 months.

One of the studies found that those given Aduhelm declined more slowly than those in the placebo group; the other found it didn’t help. “At best, the drug slowed down an already slow-moving disease by one-quarter to one-third,” says Wolk, whose medical center participated in the clinical trials.

It’s approved for people in the early stages of Alzheimer’s. The drug’s questionable clinical benefits in those with very mild symptoms suggest that it’s highly unlikely to help people with moderate to severe cognitive impairment, says Constantine Lyketsos, MD, director of the Memory and Alzheimer’s Treatment Center at Johns Hopkins University School of Medicine in Baltimore.

In studies, about 40 percent of patients developed brain swelling, sometimes along with tiny brain bleeds. About 1 in 4 people with brain swelling also experienced headaches, confusion, vision changes, or nausea. Other possible side effects include diarrhea and falls, and allergic reactions are possible.

It’s unclear. The Centers for Medicare & Medicaid Services (CMS) is conducting a formal review to decide on a national policy. Some Blue Cross Blue Shield plans have already said they won’t cover it, and other insurers are waiting on the CMS decision.

The price: $56,000 per year for the drug and more for services such as safety monitoring and MRIs. “We’ve worked out that it would cost about $100,000 to treat someone with Aduhelm for a year,” Lyketsos says.

Talk with your Alzheimer’s disease specialist about whether it might be appropriate. If so, you’ll need cognitive tests and probably a lumbar puncture or positron emission tomography (PET) scan to confirm the presence of brain amyloid.

Because side effect risks may well outweigh potential clinical benefits, ask how your doctor will monitor you for those effects and when you’d need to stop taking the drug, Lyketsos says. And be aware that you may face significant out-of-pocket costs.