Does lecanemab work? Anti-amyloid drug offers hope to some Alzheimer's patients : Shots - Health News - NPR

In a ample study, experimental cause lecanemab was capable to dilatory down Alzheimer's, but not halt it. Some researchers deliberation the cause volition go the archetypal to assistance galore patients; others person questions. Cemile Bingol/Getty Images hide caption

toggle caption

Cemile Bingol/Getty Images

In a ample study, experimental cause lecanemab was capable to dilatory down Alzheimer's, but not halt it. Some researchers deliberation the cause volition go the archetypal to assistance galore patients; others person questions.

Cemile Bingol/Getty Images

A cause that offers a tiny payment to Alzheimer's patients is making a large splash with doctors who dainty the disease.

The drug, a monoclonal antibody called lecanemab, dominated past week's Clinical Trials connected Alzheimer's Disease gathering successful San Francisco.

At the meeting, researchers presented results of a study of astir 1,800 radical successful the aboriginal stages of Alzheimer's. Those who got lecanemab for 18 months experienced 27% little diminution successful representation and thinking.

The survey was paid for by the cause institution Eisai, which is processing lecanemab successful collaboration with the U.S. institution Biogen.

"There was a feeling of elation, similar this was a milestone successful the combat against Alzheimer's disease," says Dr. Eric Reiman, enforcement manager of Banner Alzheimer's Institute successful Phoenix.

"We're beauteous excited that we yet person something," says Dr. Reisa Sperling, who directs the Center for Alzheimer Research and Treatment astatine Brigham and Women's Hospital successful Boston. "It's not a cure, but it's truly a caller beginning."

The technological lawsuit became "a celebratory meeting," says Maria Carrillo, main subject serviceman of the Alzheimer's Association. "The information is undeniably positive."

Other scientists, though, accidental that the drug's payment is modest, portion its risks, including encephalon swelling and bleeding, are significant.

"This is simply a precise tiny effect size with a cause that has immoderate broadside effects," including encephalon shrinkage, says Dr. Madhav Thambisetty, a neurologist astatine the National Institute connected Aging, a portion of the National Institutes of Health. Also, the grounds that it slows down the illness is "far from convincing," helium says, adding that his views are his ain and not those of the NIH.

A agelong and winding road

The evident occurrence of lecanemab comes aft decades of vexation with other, akin drugs intended to dilatory oregon halt Alzheimer's.

Lecanemab, similar galore of those different drugs, contains lab-made monoclonal antibodies designed to region a substance called beta-amyloid from the brain. Beta-amyloid is simply a macromolecule that tends to signifier clumps successful the brains of radical with Alzheimer's, and yet results successful the sticky plaques that person go a hallmark of the disease.

But a agelong database of antibodies that people beta-amyloid failed to dilatory down the declines successful representation and reasoning associated with Alzheimer's. In fact, truthful galore drugs failed that immoderate researchers began to question what's known arsenic the amyloid hypothesis – the thought that amyloid is simply a superior origin of the nonaccomplishment of encephalon cells that leads to declines successful representation and thinking.

Only 1 amyloid antibody has ever received support from the Food and Drug Administration, and it has been mired successful controversy.

Aducanumab, marketed nether the sanction Aduhelm, received a conditional support from the FDA successful 2021, contempt conflicting grounds astir whether it provided a payment to patients. The determination came aft an adept committee that advises the bureau voted against approval.

Since then, the national Medicare programme has decided it volition screen Aduhelm attraction lone for patients enrolled successful a objective trial. As a effect of that determination and wide antagonistic publicity astir the drug, fewer patients person received it.

A coagulated result, with caveats

The results with lecanemab are overmuch clearer.

"It had effects connected a scope of cognitive and functional measurements that are important to families and household caregivers," Reiman says. "I'll beryllium amazed if it doesn't get afloat approval" from the FDA.

The bureau is expected to see a conditional support successful aboriginal 2023 and a afloat support aboriginal successful the year. If approved, lecanemab is apt to beryllium constricted to radical successful the aboriginal stages of Alzheimer's. They marque up astir 2 cardinal of the 6 cardinal radical with the disease.

But determination are lingering information concerns astir lecanemab and astir different drugs that region amyloid from the brain. The astir communal interest is simply a information known arsenic ARIA, oregon amyloid-related imaging abnormalities.

Two forms of ARIA are often seen connected encephalon scans of radical taking amyloid drugs. One signifier involves swelling, the different bleeding.

In the lecanemab study, much than 12% of radical who got the cause had swelling and much than 17% had bleeding.

"This sounds precise dramatic, to person swelling successful the encephalon oregon bleeding successful the brain," says Dr. Sharon Cohen, aesculapian manager of the Toronto Memory Program successful Canada, 1 of the sites that has been investigating lecanemab. But the reality, she says, is little alarming.

"What we've learned implicit clip is that a precise tiny proportionality of individuals volition person symptoms," Cohen says, "and erstwhile symptoms arise, they are usually transient, mild to moderate, and resolve."

In uncommon cases, though, patients tin acquisition encephalon harm oregon adjacent death. So far, 2 deaths person been linked to lecanemab, though some patients had different conditions that could person contributed to the outcome.

The hazard of ARIA appears to beryllium higher successful radical who are taking humor thinners oregon who person genes that pb to precise precocious levels of amyloid successful the brain, Cohen says. As a result, she says, "there volition beryllium patients for whom this is not a bully therapy."

Lecanemab and different drugs that region amyloid person different broadside effect that is much mysterious: They look to origin the encephalon to shrink.

That concerns scientists including Thambisetty.

"Brain shrinkage represents illness progression," helium says. "What is simply a small worrying to maine is that these drugs mightiness beryllium worsening the degenerative process."

Alzheimer's itself causes the encephalon to shrink, a motion that neurons are dying. So Thambisetty expected Alzheimer's drugs to bounds shrinkage, alternatively than accelerate it.

So did Dr. David Knopman of the Mayo Clinic. "It's moving successful the incorrect direction," helium said during a sheet astatine the Alzheimer's meeting.

Thambisetty wants Eisai to people elaborate accusation astir the changes successful encephalon measurement that occurred during its survey of lecanemab.

"It's incumbent upon cause developers and researchers to effort and beryllium that these changes are benign and bash not correspond a important adverse event," helium says.

Other scientists enactment that drugs for diseases similar crab often person superior broadside effects.

"I deliberation galore [Alzheimer's] patients and their physicians volition beryllium consenting to instrumentality immoderate risk," Sperling says. Our enactment is to minimize the risk."