In November, pharma giant Eli Lilly announced that its experimental drug for Alzheimer's, solanezumab, did not improve symptoms in a study of 2,100 patients with mild dementia. The company's stock price plummeted after the news.
The drug targeted "amyloid plaques," proteins that build up in the brains of people with Alzheimer's. Its failure undermines the amyloid strategy — which is at the heart of several other experimental drugs as well.