Great hope has been placed in new types of drugs that target a protein called beta-amyloid. Accumulations of beta-amyloid in the brain are believed by many to be what causes Alzheimer's disease.
Now, the Cochrane research network presents an analysis in which they reviewed 17 clinical studies with a total of over 20,000 participants. Their conclusion is that treatment with drugs targeting plaques reduces their amount in the brain, but the effect on cognition is not clinically relevant.
“Unfortunately, the evidence suggests that these drugs do not make a meaningful difference for patients,” said the study’s lead author, Francesco Nonino, of the IRCC’s Institute of Neurological Sciences in Bologna, Italy, in a press release.
“Clumped substances”
The studies include nine substances that bind to the amyloid plaques in different ways. One of them is Leqembi, containing the substance lecanemab, which was approved in the EU in April 2025; another is Kisunla, containing the substance donanemab, which was approved in September.
Hugo Lövheim, chief physician at the Geriatric Center, Norrland University Hospital, and professor at Umeå University, opposes the conclusions of the analysis.
They have lumped together substances that have a demonstrated effect with substances that do not, which leads to a dilution of the results.
He says that although all the substances included in the analysis are antibodies that bind to the amyloid plaques, this happens in different ways. Lecanemab and donanemab, which have already been approved as drugs, have shown some slowing of cognitive decline in patients with Alzheimer's disease.
You should be aware that the effects are quite small even if it is given early in the disease.
Not yet available
Lecanemab is not currently available in Sweden because the NT Council, a cooperation body for Swedish regions, has not yet announced how it will be introduced. Donanemab is even earlier in the process.
Many hope that in the future it will be possible to identify certain groups of patients for whom the substances have the most effect.
There is a lot of research into many different substances in Alzheimer's right now.
Alzheimer's is the most common form of dementia. In Sweden, just over 100,000 people are affected.
A characteristic of the disease is that brain tissue is gradually destroyed.
The most important risk factors are old age and heredity. Lifestyle also has an impact.
The likelihood of being affected increases significantly after the age of 65.
According to studies, approximately 40 percent of cases can be traced to lifestyle factors. These include high blood pressure, diabetes and other metabolic diseases, as well as physical inactivity.
The Cochrane analysis included studies with the substances: aducanumab, bapineuzumab, crenezumab, donanemab, gantenerumab, lecanemab, ponezumab, remternetug and solanezumab.
Source: Alzheimer's Foundation, Dementia Center, Cochrane
