A potential Alzheimer’s disease treatment called BAN2401 is causing both excitement and criticism after Eisai, a Japanese drug company, presented data from a clinical trial suggesting the treatment slows cognitive decline and clears the amyloid-β proteins that congest the brains of people with the disease.
“It was a very impressive data set—better than expected,” says Dennis Selkoe, a Harvard University neurologist who saw the results of the 18-month Phase IIb trial presented at the Alzheimer’s Association International Conference in Chicago. “They didn’t cure the disease by any means, but this will probably be the strongest data yet for a disease-modifying Alzheimer’s treatment.”
BAN2401, an antibody being developed by Eisai and Biogen, targets amyloid-β, a strategy that has caused high-profile failures at other drug companies. Brain imaging in the new study revealed that 80% of people on the highest dose were amyloid-negative by 18 months.
Perhaps more importantly, the highest dose of BAN2401 slowed cognitive decline by 30% compared with the placebo in people with mild Alzheimer’s, according to one newly designed measure of cognition. Those results led Eisai’s scientists to declare their study the “first large clinical trial to support the amyloid hypothesis.”
Investors were more skeptical. Biogen’s stock rose steadily in anticipation of the results but dropped sharply on the news. The emphasis on the novel cognition measure worried some investors, while others poked holes in the trial’s design.
For instance, only 161 people received the highest dose, and the study also excluded people with the APOE4 gene, a high risk factor for Alzheimer’s, from the highest dose. A larger study will likely be required before BAN2401 is considered for approval.