ARIA with edema or effusions (ARIA-E) occurred in 24.4% of donanemab-treated patients in the placebo-controlled trials and 19.8% of donanemab-treated patients in the open-label extension.

Because the firm skull bone encloses the brain with very little space for blood or swelling to expand, a brain hemorrhage squeezes and compresses brain tissue – causing brain damage. If a blood ...