What you need to know about possible new Alzheimer's drug

When Eisai Co. and Biogen Inc. announced the clinical results of a new medication for Alzheimer's disease last week, it gave a lot of people hope.

The new drug — called lecanemab — was tested on about 1,800 people and showed a 27% reduction in cognitive decline compared with people on a placebo after 18 months. There were side effects, including brain bleeds or swelling. Of the people taking the medication, 21.3% experienced the side effects compared with 11.3% in the placebo group.

"It's always hopeful," said Dr. John Bertelson, a behavioral neurologist at UT Health Austin and Dell Medical School.

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What is lecanemab?

Lecanemab — which won't be considered for approval by the FDA until next year — is similar to another new medication, aducanumab, that became available last year. Both are monoclonal antibodies that target the biology of the disease. The lecanemab initial results, though, are more promising than what was found with aducanumab, Bertelson said.

Both work on the amyloid hypothesis — which holds that Alzheimer's is caused by the accumulation of a protein called beta-amyloid in the brain. The medications work to reduce that protein.

The amyloid hypothesis has been debated, because some of the medications used to try to get rid of the protein haven't shown benefits in terms of reduced symptoms. "We're wondering if we're barking up the wrong tree," Bertelson said.

If lecanemab does prove to lessen cognitive declines in patients, it would provide more evidence that the amyloid hypothesis is correct. "There are strong feelings" on both sides of the debate, Bertelson said.

Will a new drug be worth taking?

While the decline was less in the clinical lecanemab trials, it doesn't mean that the people taking the drug didn't decline. "They all decline," Bertelson said. It's also unknown if the medication merely slows the decline initially.

Still, "with a slower decline, people will have more OK years before the disease gets really bad for the patients and the caregivers," Bertelson said. "We hope that it can give people more good time."

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What about the people already diagnosed?

This medication, if approved, will be similar to aducanumab, which has already been approved by the FDA and is only for people in the early stages of Alzheimer's or mild cognitive impairment. In the early stages, people can still do many things. In the later stages or dementia, they cannot do one or more things, such as cook, manage medications or drive.

Other medications have been available for about 15 years that help slow things down but also aren't a cure, Bertelson said. People can get worse if they start taking those and then stop taking them, he said.

Doctors also prescribe medications to manage symptoms, such as depression or behavioral problems.

In addition, Bertelson said he works with families to manage symptoms without medications, such as by discussing ways that they can share the load between caregivers, address legal issues and plan for their loved one's future while they are still able to voice their wishes.

Alzheimer's usually takes five to seven years between diagnosis and death. People often die of something else before then, however, such as a heart attack or stroke.

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Are there more medications on the horizon?

Yes. Lecanemab and the already-FDA-approved aducanumab attack the amyloids. Other medications being looked at attack the tau protein in the brain of someone with Alzheimer's. Still other medications are aimed at neuroprotective agents that can help safeguard nerve cells from dying as quickly.

"It might be like cancer, where there are multiple drugs people take," Bertelson said.

The University of Texas at Austin has been part of the research into Alzheimer's medication trials as well as surgical studies. "It's been a roller coaster," he said. "I'm cautiously optimistic that one of these will be a game changer."

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Alzheimer's Association Walk to End Alzheimer's

Round Rock, Oct. 15, 9 a.m. Old Settlers Park, Lakeview Pavilion, 3300 E. Palm Valley Blvd.

New Braunfels, 9 a.m. Oct. 22, Landa Park, Dance Slab, 164 Landa Park Drive

Austin, 9 a.m. Nov. 12, Circuit of the Americas, 9201 Circuit of Americas Blvd.

Information: act.alz.org

This article originally appeared on Austin American-Statesman: What you need to know about possible new Alzheimer's drug