Hope for Alzheimer's patients
- Jenner Nex
- Apr 18
- 4 min read
Antibody drug against Alzheimer's now also available in Europe
How Lecanemab works against dementia and who is eligible for it
Hope for Alzheimer's patients:
Earlier this week, the European Commission approved the first antibody drug for the treatment of Alzheimer's in Europe. The active ingredient, lecanemab, can slow the progression of the disease in some early-stage Alzheimer's patients, but cannot cure or stop it. Early diagnosis of the first symptoms of dementia remains a particular challenge.
Alzheimer's is currently incurable:
The breakdown of brain cells caused by misfolded amyloid and tau proteins, which characterizes this dementia, cannot be stopped and is difficult to slow. However, in recent years, several antibody drugs have been developed that can destroy these protein deposits. They are thus, for the first time, addressing the root causes of Alzheimer's disease and mental impairment, but can have serious side effects. Therefore, it was long debated whether the benefits outweigh the risks.
Where is lecanemab approved?
The EU Commission has now approved one of these antibody drugs against Alzheimer's disease for the European market under strict conditions. The active ingredient, called lecanemab, is the first drug of its kind to be approved in the EU. The European Medicines Agency (EMA) has assessed the drug as safe and effective. According to the report, the benefits outweigh the risks and potential side effects.
Lecanemab has been approved in the US for almost two years and in the UK for almost a year. It was developed by Biogen and Eisai, who market it under the trade name Leqembi.
What can this Alzheimer's drug do?
Lecanemab therapy can slow the progression of Alzheimer's dementia and the associated cognitive impairments by about 30 percent. "Many patients in Europe have been waiting for approval because, from the perspective of those affected, a slowed progression of the disease makes a big difference," explains Peter Berlit of the German Society of Neurology.
However, the drug cannot cure the disease or completely halt its progression. The antibodies do not target already formed amyloid plaques, but "only" dissolve their precursors, the protofibrils. The antibody preparation cannot reverse existing nerve damage caused by protein deposits or these fibrils.
Who can receive the drug?
Lecanemab is only suitable and approved for a small subgroup of Alzheimer's patients. These people have plaques of misfolded amyloid beta proteins in their brains, but have only one or no copies of the ApoE4 gene. The ApoE genes play an important role in cholesterol metabolism, but the ApoE4 variant is considered a risk gene for Alzheimer's. Patients with two copies of the ApoE4 gene therefore have a particularly high risk of dementia, but at the same time, the risk of dangerous side effects from lecanemab, such as cerebral edema and microbleeds, is too high.
In addition, Alzheimer's patients eligible for lecanemab therapy must still be in an early stage of dementia, with only mild cognitive impairments occurring. For many patients, this therapy is therefore not an option. Early diagnosis, in particular, remains difficult and a major hurdle, as neither those affected nor doctors reliably recognize the early signs – or are willing to acknowledge them. Many wait to see whether the symptoms can be explained by other means or worsen.
How is patient selection carried out?
The German Society of Neurology (DGN) is therefore calling for improvements in early detection structures. To achieve this, the German Society of Neurology (DGN) calls for improved public awareness of dementia and its early symptoms through campaigns. Furthermore, more funding is needed for general practitioners and more specialist appointments so that suspected cases can be clarified promptly and those affected do not miss the narrow window of opportunity for lecanemab therapy, according to the professional society.
"The initial diagnostic evaluation is time-consuming; it cannot be done 'on the side.' However, careful patient selection is important to make optimal use of limited specialist resources and not overburden further diagnostics, including cerebrospinal fluid examination, imaging, and genetic testing," explains Berlit.
In the long run, it is cheaper to invest in early detection and early treatment than to diagnose the disease late and then bear the high costs of caring for dementia patients, as analyses by the German Centers for Neurology (DZNE) have shown. Therefore, it would be beneficial not only personally but also economically if the severe phase of the disease could be delayed with medication for as many patients as possible, according to the DGN.
What's the future of Alzheimer's therapy?
Treatment with lecanemab is currently administered via regular infusion by a specialist, making it labor-intensive. An application has now been filed in the US to allow the drug to be injected subcutaneously to simplify administration. This could also be applied for in Europe. Approvals for other antibody drugs such as donanemab, aducanumab, or gantenerumab, which have so far only been available in clinical trials, could follow in the future.
Source: German Society of Neurology, EU Commission
