And why do they inspire both hope and criticism?
In recent years, new Alzheimer’s drugs have garnered significant attention. This is particularly true of antibody therapies that target amyloid in the brain, including the Swedish-developed Lecanemab. At the same time, an intense debate is currently underway among researchers and policymakers, with some seeing this as a breakthrough, while others believe we are not yet close to a solution.
To understand the debate, it is important to distinguish between three things:
- biological effect
- measurable effect in studies
- actual significance for the patient
Antibody therapies are designed to:
- bind to amyloid protein in the brain
- help break down these deposits
This is one of the key mechanisms underlying Alzheimer's disease, according to the so-called amyloid hypothesis.
Large clinical trials show that drugs such as Lecanemab:
- reduces the amount of amyloid in the brain
- slows the decline in cognitive function compared to placebo
- does so in a statistically significant manner
In other words, there is a demonstrable effect.
The criticism is not that there is no effect, but rather concerns a classic question in research:
What constitutes sufficient evidence—and what counts as a meaningful effect?
It is important to understand the difference between two things:
Statistical significance → the effect is likely not due to chance
Clinical significance → the effect is large enough to matter in real-world settings
The question, then, is how significant the effect is and what it means in practice.
While the Cochrane report has had a major impact, several leading clinicians and researchers argue that the analysis risks presenting a misleading picture of developments in recent years.
There are five clearly identified issues with the report:
The report is based on class-level analysis rather than molecular-level analysis
This may sound technical, but it is crucial for understanding.
The report thus groups already known ineffective drugs with drugs that have proven efficacy.
"If you know that two drugs are effective and five are not, and then you analyze them all together, it’s not hard to see that the analysis will be misleading"
Patient groups are being conflated
The report conflates patients at different stages of the disease—some in the early stages and others in the late stages. Since we now know that the timing of treatment initiation matters, this part of the analysis becomes completely irrelevant and misleading.
Too narrow criteria for what counts as an effect
Small changes are considered insignificant in the report. This is clearly a problem because dementia disorders such as Alzheimer’s disease, like other chronic diseases, develop over a long period of time. If a treatment slows deterioration slightly each year, it can add up to several extra years of independence, even if the difference after one year seems small. Small effects become significant over time, and this has not been addressed at all.
Risks are presented out of context
Side effects are highlighted, but without specifying who they affect or how often they actually occur. All medications carry risks.
The question is never whether side effects exist, but rather who they affect and whether the benefits outweigh the risks.
Risk of incorrect decisions
The greatest risk associated with this overly broad interpretation of the Cochrane report is that it could negatively influence decision-makers—especially at a time when several countries are actively evaluating the introduction of the first disease-modifying treatments that have demonstrated efficacy.
In Sweden, a comprehensive assessment is conducted of:
- Power
- Safety
- Cost
When the NT Council evaluated Lecanemab, its conclusion was:
- There is some effect, but the benefit is considered small and uncertain
- The treatment is costly and requires resources (e.g., infusions and follow-up)
For this reason, it is not currently recommended for widespread use.
Supporters point out that:
- Even a slight improvement can be valuable, especially in a disease with no cure
- The effect may become more apparent over time
This is about how to assess value.
At Geras Solutions, we see this as an important step forward—but not a complete solution.
History has taught us that medical progress rarely happens in a single step.
Several major breakthroughs began as incomplete first-generation treatments:
Cancer, HIV, MS—early treatments had significant side effects and limited efficacy
BUT
They marked a turning point.
It wasn’t until the healthcare system began using these treatments, following up with patients, and collecting data that progress really took off.
If Sweden completely refrains from introducing these treatments, several problems will arise:
1. No clinical experience is being built up
2. No infrastructure is being developed around the treatments (covering both diagnostics and follow-up)
3. We are limited in our ability to contribute to ongoing research
4. We risk falling behind when the next generation of treatments arrives
In other words, this is just as much about current treatments and the message we want to convey to affected patients and their families right now as it is about future capacity.
The question we should really be asking is not whether or not to introduce new medications, but how to do so in a safe and educational manner.
/Simon Körösi, Chief Medical Officer, April 20, 2026