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# Panel Thumbs Down on Biogen Alzheimer’s Drug
- URL: https://www.fdaweb.com/panel-thumbs-down-on-biogen-alzheimers-drug/
- Published: 2020-11-09T12:00:00.000Z
- Updated: 2026-09-14T16:35:39.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5148039

FDA’s Peripheral and Central Nervous System Drugs Advisory Committee has voted 8 to 1 that a study involving Biogen’s Alzheimer’s drug did not provide strong evidence to support its effectiveness. The panel also voted 7 to 0 (4 votes uncertain) that a second study did not provide evidence of the aducanumab’s effectiveness for the treatment of Alzheimer’s. If FDA goes against the recommendations, aducanumab would be the first new Alzheimer’s drug approved in nearly 20 years.

During the meeting, panel members were not persuaded by an FDA briefing document’s discussion on effectiveness. An agency medical reviewer [said ](https://www.fda.gov/media/143502/download?ref=fdaweb.com)one of the clinical studies submitted by Biogen “provides substantial evidence of effectiveness to support approval.”

The briefing material did, however, acknowledge aducanumab’s checkered history. It noted that after promising clinical and biomarker data emerged from an early study, Biogen embarked on two trials of essentially identical design in 2015\. A 2019 pre-specified interim analysis for futility led to the company terminating the studies and notifying FDA. However, later examination of individual study results, including additional data that had accrued during the time the futility analysis was being conducted, identified seemingly positive results in one of the two trials.

FDA says Biogen brought the results to the agency seeking confirmation of its analysis. “FDA recognized that additional work was necessary to achieve a maximum understanding of the results and established a collaborative plan for further rigorous analysis of the data,” the briefing paper said. “These analyses ultimately led to FDA advising the applicant that submission of a marketing application seeking approval of aducanumab was reasonable.”

On the issue of safety, a frequent side effect of aducanumab has been a painful but manageable swelling of the brain called ARIA. Outside experts reportedly worried that the side effect might effectively unblind the study, informing patients that they had received the treatment and thus creating a bias in the study. The reviewers said an analysis of the data did not suggest that ARIA biased the trial.

Panel members also were concerned about FDA’s statistical reviewer, **Tristan Massie**, who wrote in the briefing paper that the one positive trial of aducanumab could not overcome the negative one. “There is no compelling evidence of treatment effect or disease slowing and … another study is needed to confirm or deny the positive study and the negative study,” she wrote.

FDA Office of Neuroscience director **Billy Dunn** told the panel that issues with the negative trial don’t “meaningfully detract from the persuasiveness” of the positive trial. He suggested the drug might still have a clear path to approval.