Biogen’s Alzheimer’s disease treatment reduced amyloid plaque in patients’ brains in an early-stage trial, in what is being hailed as “game-changing.” But although promising, onlookers remain cautious of overhyping a drug candidate that had provided weak results just last year.
The Phase 1b data, published today in Nature, showed aducanumab, an amyloid-targeting monoclonal antibody, lowered the amount of amyloid plaque in the brains of 165 patients, ages 50 to 90, with mild Alzheimer’s disease. The reduction was dose-dependent, and the study was placebo-controlled.
Brain scans showed patients who were given the highest dose, at 10 mg, by monthly intravenous infusion experienced the greatest reduction in amyloid after a year of treatment. In the study, 125 patients completed the treatment and 40 discontinued it, primarily withdrawing due to negative side effects. Treatment with the higher dose can cause serious swelling in the brain.
The trial, funded by Biogen, was not designed to test for cognitive decline. But Biogen contends that aducanumab also improved patients’ brain function.
“These early studies of aducanumab show its effectiveness in removing amyloid plaque from the brain as well as its potential effect on the slowing of cognitive decline in patients suffering from Alzheimer’s disease,” said Alfred Sandrock, MD, PhD, executive vice president and chief medical officer at Biogen, in a prepared statement.
Biogen’s aducanumab data has been hyped by the media. But the market remains wary: Biogen stock initially dropped, but rebounded in after-hours trading.
In March 2015, Biogen presented promising data on aducanumab, which showed that the drug candidate reduced amyloid in the brain and slowed cognitive decline at doses of 3 mg and 10 mg. But a few months later in July, a 6-mg dose failed to deliver promising results.
Another promising Alzheimer’s drug is Eli Lilly’s solanezumab. Although its effects were touted early on, in 2012 Lilly reported that the treatment did not work in advanced stages of Alzheimer’s disease. The company has begun a third trial testing solanezumab against a placebo in patients with mild symptoms. These results are not expected until early 2017, according to Lilly.
Pre-clinical research on Biogen’s aducanumab was originally presented in March 2013 at the International Conference on Alzheimer’s and Parkinson’s Diseases in Florence, Italy. Larger, Phase 3 trials of aducanumab in Alzheimer’s disease are currently in progress.
Many researchers believe that reducing amyloid plaque may slow the progression of Alzheimer’s disease. But this theory has not yet produced a successful Alzheimer’s treatment. The neuroscience community also has their sights set on a second brain protein, tau, which is responsible for the tangles that form in the brains of people with Alzheimer’s.
More than 5 million people live with Alzheimer’s in the U.S., a number expected to increase to 13.5 million by 2050, according to the Alzheimer’s Association.
