SFor decades, researchers around the world have been looking for a remedy for Alzheimer’s dementia – so far without success. Every active ingredient disappointed in the clinical trial. The new antibody lecanemab, which is intended to clear deposits from certain proteins in the brain, has now shown a positive effect in a phase III study. It is a monoclonal antibody designed to fight the precursors of beta amyloid. In Alzheimer’s patients, a particularly large number of these proteins aggregate to form the plaques typical of the disease and are deposited between the nerve cells in the brain. The amyloid hypothesis is the research assumption that these deposits play a central role in the development and progression of Alzheimer’s dementia, i.e. to a certain extent they are the cause of the cognitive deficits. Nerve cells die off during the disease: those affected forget more and more, lose their language, and their personality changes drastically, they die early. Conversely, researchers hoped that this development could be stopped by preventing the formation of amyloid plaques. So far, however, such antibodies have not improved the symptoms. Also, experts suspected, because the treatment came too late.
The new results of what is typically the last testing phase before a possible approval of the drug were presented at a specialist congress in San Francisco and in the “New England Journal of Medicine”. The study involved 1,795 subjects who were treated in 235 centers around North America and Europe. They were between 50 and 90 years old and had an early stage of the disease. Amyloid was detectable in the brain with special diagnostics. Around half of the patients received regular infusions with lecanemab, which is manufactured by the pharmaceutical companies Biogen and Eisai, for 18 months, the others a placebo.