Written by Dina Beasley and Julie Steenhuysen
(Reuters) – An experimental Alzheimer’s drug developed by Eisai Co (OTC:) Ltd and Biogen Inc (NASDAQ): significantly slowed cognitive and functional decline in a large trial on patients in the early stages of the disease, the two companies said on Tuesday.
The injected drug, lecanemab, slowed the progression of cerebral wasting disease by 27% compared to placebo, achieving the study’s main goal, and providing a clear win for companies and possibly patients and their families desperate for effective treatment.
The results of the 1,800-patient trial prove the old theory that removing sticky deposits of a protein called amyloid-beta from the brains of people with early Alzheimer’s disease can delay the progression of the debilitating disease, Isai said.
“It’s not a big effect, but it’s a positive effect,” said Ronald Petersen, director of the Alzheimer’s Disease Research Center at the Mayo Clinic in Rochester, Minnesota, adding that the findings were very important to Alzheimer’s research.
“This means that treating amyloid is a step in the right direction,” he said.
Wall Street analysts, such as Salem Syed at Mizuho Securities, said the results would be considered a “win” if lecanemab slowed the decline rate by about 25%, and that both companies’ shares could jump in the news.
Shares of Biogen and Eisai are halting, but shares of Eli Lilly & Co (NYSE:), which is also developing an Alzheimer’s drug, rose 6.7% in post-closing trading.
Lecanemab, like the company’s previous drug Aduhelm, is an antibody designed to remove amyloid deposits. Unlike Aduhelm, lecanemab targets forms of amyloid that have not yet clumped together.
The so-called amyloid hypothesis has been challenged by some scientists, especially after the controversial US Food and Drug Administration approved Aduhelm in 2021 based on its ability to remove plaque rather than proving that it helped slow cognitive decline. The decision came after the US Food and Drug Administration’s panel of external experts advised against approval.
Aduhelm was the first new Alzheimer’s drug approved in 20 years after a long list of notable industry failures.
Eisai, the leader of the lecanemab 50-50 Partnership, is seeking FDA approval under the same fast track as Aduhelm, with a decision expected in early January. But the Japanese drugmaker said Tuesday it will use the results of the new efficacy to submit lecanemab for conventional Food and Drug Administration review.
The company said it will also seek a license in Japan and Europe during the current fiscal year, which ends on March 31.
The Phase III trial evaluated the drug’s ability to reduce cognitive and functional decline based on the Clinical Dementia Rating – Total Boxes (CDR-SB), a numerical scale used to determine the severity of dementia in patients in areas such as memory, orientation, judgment, problem-solving and personal care.
The rate of ARIA-E, a side effect of brain swelling associated with anti-amyloid treatments, was 12.5% in the lecanemab group, versus 1.7% in the placebo group.
The companies said that while the side effects appeared on the imaging, many of those cases were not asymptomatic. They said symptomatic brain swelling was observed in 2.8% of those in the lecanemab group and not in any of the placebo group.
The trial also tracked the rate of minute bleeding in the brain, which occurred at a rate of 17% in the lecanemab group, and 8.7% in the placebo group.
The two companies said the total incidence of both conditions was 21.3% in the lecanemab group and 9.3% in the placebo group, rates that are within the expected range.
The side effect was present, Petersen said, but much less than that of Aduhelm, and “certainly can be tolerated.”
Aduhelm’s approval has been a rare bright spot for Alzheimer’s patients, but critics have demanded more evidence that drugs targeting amyloid are worth the cost.
Controversy and reluctance by some advocates to cover Aduhelm led Biogen to lower the price of the drug to $28,000 per year from $56,000 initially.
But the US government’s health care plan for people 65 and older said this year it would pay for Aduhelm only if patients were enrolled in a valid clinical trial, sharply reducing use of the drug. Because Alzheimer’s is a disease of aging, an estimated 85% of patients who qualify for the drug are covered by the government’s plan.
The number of Americans living with Alzheimer’s disease is expected to rise to about 13 million by 2050 from more than 6 million currently, according to the Alzheimer’s Association. Globally, that number could rise to 139 million by 2050 without effective treatment, according to Alzheimer’s Disease International.
Other antibodies that target plaques in the late stages of development in Alzheimer’s patients include Roche Holding AG’s (OTC:) gantenerumab and Eli Lilly’s donanemab.