A phase 3 clinical trial involving 1,795 patients with early-stage Alzheimer’s disease has shown that an experimental drug for the treatment of Alzheimer’s, lecanemab, slowed cognitive decline by 27% compared to placebo. It is, without a doubt, one of the most anticipated news items for decades and could provide hope for the more than 50 million people – around 800,000 in Spain – who suffer from this neurodegenerative disease.
The results of the work will be presented on November 29 at the Congress of Clinical Trials on Alzheimer’s (CTAD) and will also be published in a scientific journal once they are reviewed by independent experts, so we must wait and take them with caution. . In fact, last year the FDA (Food and Drug Administration of the United States) approved Aduhelm, the first drug against Alzheimer’s to be approved in 20 years and which had been developed by Biogen, one of the companies that have created lecanemab, and that it has not achieved the expected improvements, so Biogen has stopped marketing it.
The two companies that have jointly developed lecanemab, the American Biogen and the Japanese Eisai, announced last Tuesday, September 27, that their product can slow down the cognitive deterioration experienced by Alzheimer’s patients because it targets amyloid plaques present in the brain. of the patients, one of the main hypotheses of the origin of this type of dementia, which until now has not been proven.
This theory is known as the ‘amyloid hypothesis’ and argues that β-amyloid protein progressively accumulates in the brain as toxic deposits and eventually triggers dementia. However, experts believe that Alzheimer’s is a very complex disease due to different causes or risk factors, and that it is very unlikely that the accumulation of amyloid beta is the only cause.
Questions and answers about lecanemab, a new drug against Alzheimer’s
But what really matters to patients and their loved ones and caregivers is how this new drug works, for whom it is indicated, how it is administered, its effectiveness and possible side effects, when it will be approved and when it will be available in Spain.
How does lecanemab work to slow cognitive decline caused by Alzheimer’s?
Lecanemab is a monoclonal antibody that is administered intravenously, and has been designed taking into account one of the main hypotheses for the origin of Alzheimer’s, which is the formation of amyloid plaques that prevent the connection between neurons and cause their degeneration. It is responsible for removing amyloid deposits, but, unlike Aduhelm, it targets the forms of amyloid that have not yet been grouped, that is, it acts before large plaques are formed in order to prevent the progression of amyloid. this type of dementia by binding an antibody to beta amyloid and removing it to prevent nerve cells from being destroyed.
How has the efficacy and safety of lecanemab been proven?
The 1,795 individuals who participated in the clinical trial (residents of the United States, Japan and Europe) suffered from mild cognitive impairment or early-stage Alzheimer’s and had amyloid beta abnormalities. They were divided into two groups, and the experimental drug was administered to the patients of one of them once every two weeks for 18 months. The other group received placebo.
At the end of this time, patients treated with lecanemab had experienced a 27% reduction in the worsening of symptoms compared to those who received placebo, although already six months after the start of the study “the treatment showed statistically significant changes”. significant” in cognitive evolution, according to their results. Regarding its possible side effects, it has been observed that it can cause inflammation (3%) or cerebral bleeding (21%).
It is not known how long the drug will continue to be effective in stopping cognitive decline, as it has only been tested for 18 months so far.
Which patients will benefit from treatment with lecanemab?
Treatment with lecanemab is indicated for patients in the early stages of the disease or with mild Alzheimer’s, since what it does is stop cognitive deterioration, but it does not help to recover the mental capacity that the patient has already lost with the progress of dementia . The drug has to be administered intravenously, and patients need to be followed and have imaging tests done to monitor for possible side effects on the brain.
When will lecanemab arrive in Spain?
The regulatory bodies of the United States have already begun to review the drug to evaluate its potential approval, and their decision could be announced in the first days of January 2023. The objective of the pharmaceutical companies that have created the drug is to obtain its approval and commercialization in the United States, Europe and Japan before the end of 2023, according to Haruo Naito, CEO of Eisai.
However, it could take two years before lecanemab is available in our country, since it is necessary to wait for the European and Spanish health authorities to give their approval. First, it must be approved by the European Medicines Agency (EMA), and then the Spanish Medicines Agency (Aemps) has to grant its approval. Juan Fortea, Coordinator of the Behavior and Dementia Study Group of the Spanish Society of Neurology (SEN), has explained in statements to Medical Writing that “it may take about two years to be implemented in Spain and it will be given in very specific indications. Few patients who currently have Alzheimer’s will be able to benefit from it, since many of them are already in advanced stages.”
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