Roche Drug for Alzheimer’s Cleared Less Amyloid Than Hoped (1)

Roche Holding AG’s experimental Alzheimer’s disease drug was far less effective than hoped at clearing a toxic protein from the brain, according to findings from two studies that may explain why it failed when a rival therapy succeeded.

Amyloid, an abnormal protein in Alzheimer’s patients’ brains, dropped to a target threshold in only about a quarter of treated patients, Roche said Wednesday in a presentation at the Clinical Trials in Alzheimer’s Disease conference in San Francisco. A smaller study had suggested that the drug could hit that target in about half of patients.

The results scuttle hopes for gantenerumab ...