Two Antiamyloid Antibodies Will Undergo Further Study

Gantenerumab May Reduce Amyloid Burden

Gantenerumab will be examined in further trials, following investigators’ analyses of open-label extension data from the Scarlet Road and Marguerite Road studies, said Dr. Klein. Patients in these studies were randomized to either 105 mg or 225 mg of the antibody. Researchers observed no significant cognitive benefits of therapy, but noted trends toward improvement with the higher dose, as well as dose-dependent plaque clearance. These results encouraged researchers to examine higher doses in 52-week open-label extensions of each study.

Dr. Klein presented new imaging data for these studies. In both studies combined, 40 patients were maintained for six to nine months on the highest doses (ie, from 900 mg to 1,200 mg). Of these participants, 17 had almost total clearance of their amyloid burden. Their scans, Dr. Klein said, appear to show traces of amyloid or to be amyloid-negative. The effect was consistent, regardless of the amount of amyloid at baseline. “These are encouraging biomarker data,” he said. “We are going into our new phase III studies, Graduate I and II, optimistic.”

According to a Roche press release, these studies will target patients with prodromal to mild disease at the higher doses. Emails to Roche and its German partner, MorphoSys, were not returned by press time. Dr. Klein’s comments suggest that studies of gantenerumab will continue.

—Michele G. Sullivan