"The promising effects of Aducanumab are currently being investigated in two large phase three clinical studies to further evaluate safety and efficacy. Involving over 300 centers in 20 countries throughout North America, Europe, and Asia, these studies are evaluating the effectiveness and safety of the antibody on a total of 2,700 patients with early-stage Alzheimer's disease."

https://www.sciencedaily.com/release...0831133555.htm

They will be in a better position to make a judgement after these studies have been completed.