The new antibody drug Donanemab from the US pharmaceutical company Eli Lilly shows the first results in a clinical study. But there are also strong side effects.
The suffix of the new drug – donanemab – indicates the type of drug: MAB stands for monoclonal antibody. Such a drug is always aimed at a specific target, for example a protein.
In this case, the target is called amyloid-beta, or just Aβ. This is a piece of protein that is deposited in the brain and blood vessels of people with Alzheimer’s disease. The idea of an antibody drug, on the other hand, is that if Aβ can be prevented from being deposited in the brain, then the course of the disease can also be slowed down.
promising Results
And indeed, donanemab seems to do just that. In a clinical study with more than 1700 participants, the subjects who received the drug showed around 35 percent less cognitive impairment compared to the placebo group. In almost half, 47 percent, the disease had stopped progressing in a year.
Those treated with the drug were also about 40 percent less impaired in activities of daily living. In more than half, the Aβ deposits in the brain could be completely removed after one year and in almost three quarters after another six months.
Strong side effects
Experts call these results encouraging and superior to previous studies. But donanemab is not the magic bullet either. It seems to slow down the progression of the disease, but this drug cannot stop or even cure Alzheimer’s either.
In addition, unlike other antibody drugs, donanemab has relatively strong side effects. Serious brain swelling or bleeding occurred in more than one and a half percent of the subjects. Two people even died from it, possibly three.
“The Right Approach”
Linda Thienpont, scientific director of the Alzheimer Research Initiative, told the Science Media Center Germany: “Unfortunately, donanemab is not a game changer for those affected either, but it may be a step in the right direction.”
Christian Haass, Head of the Department for Neurodegenerative Diseases at the Ludwig Maximilians University in Munich, assesses the results as follows: “The results of the press release on donanemab look really good. Donanemab is now the second anti-Aβ antibody that clearly slows down memory loss. Certainly, there is still a lot to improve in terms of side effects and more effective therapy, but reducing amyloid is certainly the right approach to at least slow down the disease.” It should finally be clear that the amyloid hypothesis is “no longer a hypothesis, but a fact”.
Approach also followed by other companies
The data published by the US pharmaceutical company Eli Lilly has so far only been published in a press release and not yet in a publication checked by experts. But they show that freeing Aβ deposits is at least a partially promising therapeutic approach, perhaps also as part of a combination therapy.
Other companies, such as the Dutch pharmaceutical manufacturer Vivoryon, are also working on drugs with a similar principle of action. Clinical trial results are expected this year or next.