Treatment with aducanumab produced a dose- and time-dependent reduction of amyloid plaque in the brain. Amyloid plaque is believed to play a key role in the development of the symptoms of AD. In exploratory analyses, a dose-dependent, statistically significant effect of slowing clinical decline was observed on the Mini Mental State Examination (MMSE) and Clinical Dementia Rating (CDR) scales.
“This is the first time an investigational drug for Alzheimer’s disease has demonstrated a statistically significant reduction on amyloid plaque as well as a statistically significant slowing of clinical impairment in patients with prodromal or mild disease,” said Alfred Sandrock, M.D., Ph.D., group senior vice president and chief medical officer at Biogen Idec. “Based on these results, we are advancing the aducanumab clinical program to Phase 3 with plans to initiate enrollment later this year.”
Summary from Business Insider:
When the drug was tested at a high dose, it showed a 71% reduction in the plaque after 54 weeks compared to the control drug. Investors had been expecting a 30% reduction, according to TheStreet's Adam Feuerstein. These percentages are measured by the Clinical Dementia Rating the industry uses.