The results of the 1,800-patient trial support the long-standing theory that removing sticky deposits of a protein called beta amyloid from the brain can slow the progression of the disease.
An experimental Alzheimer’s drug made by the companies Eisai Co Ltd and Biogen slowed cognitive and functional decline in a large trial involving patients in the early stages of the disease. An advance that would be a great boost for similar studies carried out by Roche and Eli Lilly.
To date, numerous drug manufacturers have tried to find an effective treatment for this disease that affects some 55 million people worldwide, without success. The figure could reach 139 million in 2050, according to the organization Alzheimer’s Disease International.
Eisai said the results of the 1,800-patient trial support a long-standing theory that removing sticky deposits of a protein called amyloid beta from the brains of people with early-stage Alzheimer’s can slow the progression of the debilitating disease.
The drug, lecanemab, slowed the progression of the disease by 27% compared to a placebo, fulfilling the main objective of the study. Eisai is seeking expedited approval from the US Food and Drug Administration (FDA), a decision on which is expected in early January. His goal is to achieve full approval and marketing of the drug in the United States, Europe and Japan by the end of 2023, his CEO, Haruo Naito, told reporters in Tokyo.
It’s still “too soon”
Lecanemab, like the partners’ previous drug, Aduhelm, is an intravenous antibody designed to remove amyloid deposits. Unlike Aduhelm, lecanemab targets forms of amyloid that have not yet clumped together. “If you can slow down a disease by almost 30%, that’s fantastic,” said Dr. Jeff Cummings, director of the Chambers-Grundy Center for Transformative Neuroscience at the University of Nevada Las Vegas.
The so-called amyloid hypothesis has been questioned by some scientists, especially after the controversial approval of Aduhelm by the US Food and Drug Administration in 2021, based on its ability to remove plaques and not on the evidence of to help slow down cognitive decline. The decision came after the FDA’s own panel of outside experts advised against its approval.
Although the early results of lecanemab are convincing, it is still “very early” to determine whether the effects are clinically significant, said Dr. Kristian Steen Frederiksen, director of a clinical trials unit at the University of Copenhagen. Alzheimer’s “is an extremely complex disease, and amyloid-related pathology is unlikely to be the only player,” he said. “So targeting a single target is not likely to produce large effects.”
The phase III trial evaluated the drug’s ability to reduce cognitive and functional decline according to the Clinical Dementia Rating-Sum of Boxes (CDR-SB), a numerical scale used to quantify the severity of dementia in patients in areas such as memory, orientation, judgment and problem solving, and self-care.
The rate of cerebral edema side effects associated with anti-amyloid therapies was 12.5% in the lecanemab group versus 1.7% in the placebo group. However, many cases did not cause symptoms, as symptomatic brain swelling was seen in 2.8% of patients in the lecanemab group.
Cerebral microbleeds occurred in 17% in the lecanemab group and 8.7% in the placebo group.
Petersen said the rate of side effects was much lower than with Aduhelm and “certainly tolerable.”
Eddie is an Australian news reporter with over 9 years in the industry and has published on Forbes and tech crunch.