FDA AdCom roster shrinks as two quit over Aduhelm approval

Mayo Clinic neurologist David Knopman on Wednesday became the second member of the FDA's Peripheral and Central Nervous System Drugs Advisory Committee (AdCom) to resign in protest at the agency's decision earlier this week to approve Biogen and Eisai's Alzheimer's disease drug Aduhelm (aducanumab).

The 11-member panel was nearly unanimous last November in concluding that the clinical evidence did not support approval of the anti-amyloid antibody. On Tuesday, Washington University neurologist Joel Perlmutter, a member of the advisory group who had voted against the approval, resigned from the committee as well.

In its approval announcement on Monday, the FDA said it cleared Aduhelm using an accelerated approval pathway that had not been discussed at the November AdCom meeting. The agency, which usually follows the advisory panel's recommendations, but is not obligated to, explained that its decision was based on the drug's ability to reduce beta-amyloid, arguing this was "reasonably likely to result in clinical benefit."

Knopman did not participate in the AdCom vote, having been recused over a conflict of interest because he was an investigator on clinical trials of the drug (see ViewPoints: Inauspicious start to a big week for Biogen's aducanumab). However, he stated Wednesday that he "was very disappointed at how the advisory committee input was treated by the FDA," adding "I don't wish to be put in a position like this again."