In 2021, Biogen Inc.’s Aduhelm (aducanumab) became the first amyloid-targeting therapy to win U.S. FDA approval in Alzheimer’s disease. After decades and dozens of failed phase III trials, the drug was granted accelerated approval in June 2021. In January 2022, however, the U.S. Center for Medicare & Medicaid Services said it would only cover use of Alzheimer’s MAbs targeting amyloid in NIH trials or trials it approved, thus appearing to call into question the rigor of FDA-approved trials.