17 Dec 2021

The European Medicines Agency rejected Biogen and Eisai’s marketing application for aducanumab (trade name Aduhelm) in a tersely worded decision on December 16. In five brief sentences, the EMA noted that clinical results from the two Phase 3 trials conflicted, and that aducanumab carries risks of brain swelling and bleeding that may not be adequately managed in clinical practice. “The Agency’s opinion was that the benefits of Aduhelm did not outweigh its risks,” the EMA concluded.

The decision was expected, as the EMA’s Committee for Medicinal Products for Human Use (CHMP) had recommended against approval in November. Biogen has 15 days to appeal the EMA’s decision, and the company has already indicated it will do so. The EMA will then have 60 days to make a final determination.

Meanwhile, Biogen described plans for a confirmatory trial of aducanumab, as required by the U.S. Food and Drug Administration’s accelerated approval (Jun 2021 news). In a December 16 press release, the company announced it plans to start enrolling for a global placebo-controlled clinical trial in May 2022. Biogen aims to include 1,300 participants with early Alzheimer’s disease, who will take the drug for 18 months. The company expects results by 2026.

[Editor's update: On December 20, Biogen announced it would halve aducanumab's price from U.S. $56,000 per year to $28,200 per year.]—Madolyn Bowman Rogers