Myriad Genetics is discontinuing development of Flurizan after the drug failed in a closely watched Phase III clinical study. In a statement, the drugmaker said the med didn’t improve cognition by a statistically significant amount compared to a placebo or improve the ability of patients to go about daily living.

The failure is significant because Flurizan was one of the first drugs to reach late-stage testing that tried to prevent the buildup of amyloid plaque in the brain, a focus of much research into Alzheimer’s. Whether this will raise questions about other drugs targeting amyloid plaque remains to be seen.

Wyeth and Elan are jointly developing a drug that tries to block amyloid plaque and, so far, have generated considerable interest, even though preliminary Phase II results were mixed. Lilly is also in late-stage testing of a drug that works simlarly to Flurizan.