More details are emerging over the U.S. Food and Drug Administration (FDA)’s controversial approval of Biogen’s Aduhelm (aducanumab) for Alzheimer’s disease. The drug was approved on June 7 under the agency’s accelerated approval pathway, despite the agency’s Peripheral and Central Nervous System Drugs Advisory Committee voting against the drug in November 2020 and having been assured at that time the agency was not considering an accelerated approval.
An accelerated approval allows for surrogate endpoints—in the case of Aduhelm, removal of amyloid plaques—instead of clinical evidence of improvement in cognition and memory. It also requires post-marketing studies to be conducted, although Biogen has nine years to run those studies. Three members of the advisory committee have resigned over the approval.
Numerous researchers are pushing back on the decision to approve the drug based on decrease of amyloid, arguing that a number of studies show that drugs that target and successfully clear amyloid don’t result in clinical improvements.
Janet Woodcock, acting FDA commissioner, says she was not involved in the approval, but defended it, saying she was “fairly confident” that clearing amyloid helps patients’ cognition. “I feel it is a very solid accelerated approval,” she said.
Matthew Schrag, a researcher into Alzheimer’s at Vanderbilt University Medical System, does not believe the FDA has produced good new data showing that cutting amyloid benefits patients. “The arguments are well-trodden and don’t account for the fact that the trials have not demonstrated a reproducible clinical benefit,” he told The Washington Post.