There’s a new class of immunotherapy to treat Alzheimer’s disease. What do you need to know about them?

Alzheimer’s disease occurs from a toxic molecule called Amyloid beta. It is a normal byproduct of brain metabolism. Under normal circumstances, our brain can clear it. However, in Alzheimer’s disease this clearing mechanism fails and so amyloid accumulates in the brain. It is toxic to the nerve cells.

Now, it turns out that if we remove amyloid deposits from the brain, we can slow down the damage. That’s exactly what these new immunotherapies do. They are monoclonal antibodies. They enter the brain and attach to amyloid beta. So the immune cells can recognize it and remove it from the brain.

This concept seems to work. After a few months of treatment, the amyloid burden in the brain drops. And cognitive decline slows down by a small amount.

Side effects? The most feared side effects are brain swelling and bleeding. When the immune system enters the brain and clears out Amyloid from the brain, that process can damage small blood vessels, and cause microscopic areas of bleeding and swelling. This can occur in more than 20% of cases. Usually it’s mild but occasionally it can be severe and make things worse.

We are still collecting data for better understanding of how effective they really are. It’ll take another 2-3 years to get more clarity on this.