January 2024 | Ryan Institute Co-Executive Director and Herrmann Professor of Neuroscience William Van Nostrand began a new collaboration with Eli Lilly this month to investigate the molecular mechanisms responsible for the potential risk of serious brain bleeds that was identified in Alzheimer’s disease immunotherapies FDA-approved last year.

Working with transgenic rat models developed by his lab, Van Nostrand hopes to better understand why these brain bleeds might happen and the risk factors involved.

Immunotherapies offered a breakthrough in Alzheimer’s disease treatment in 2023 when they showed some ability to slow the progression of disease. The treatments work by removing the build-up of amyloid protein “plaques” that is thought to be a key contributor to disease development. The potential risk for serious or fatal brain bleeds, however, creates some concern and the need for more information to understand what causes the bleeds and who should avoid treatment.

Van Nostrand is a foremost expert in cerebral amyloid angiopathy (CAA), a brain blood vessel disorder that causes microbleeds and hemorrhaging, and often occurs with Alzheimer’s disease. The project will use transgenic rat models of CAA, providing a unique way to isolate and study the link between the immunotherapy approach and the brain bleed risk.

“These drugs are not cures, but they have shown promise in slowing the rate of cognitive decline and disease progression,” said Van Nostrand. His collaboration with Eli Lilly could help determine which patients are best candidates for the treatment and whether there may be a way to reduce or eliminate the brain bleed risk.