"More importantly, lecanemab might not work very well. From the data released so far, it is unclear what difference it could make to the devastating burden inflicted by Alzheimer’s. Some doctors warn that the benefits of the drug seem so small, patients may not even notice. But others counter that any effect on Alzheimer’s deserves celebration: it proves the disease can be beaten, or at least slowed down. It’s a start, a concrete foundation to build on."
https://www.theguardian.com/society/2022/nov/22/treatment-for-alzheimers-lecanemab-dementia-research