Finding Treatment Effects in Alzheimer Trials in the Face of Disease Progression Heterogeneity

Can we learn lessons from the FDA's approval of aducanumab?

On 7 June 2021, aducanumab was granted accelerated approval for the treatment of Alzheimer disease (AD) by the FDA on the basis of amyloid-lowering effects considered reasonably likely to confer clinical benefit. This decision makes aducanumab the first new drug to be approved for the treatment of AD since 2003 and the first drug to ever be approved for modification of the course of AD. Many have questioned how scientific evidence, expert advice and the best interests of patients and families were considered in the approval decision. In this article, we argue that prior to approval, the FDA and Biogen's shared interpretation of clinical trial data - that high-dose aducanumab was substantially clinically effective - avoided conventional scientific scrutiny, was prominently advanced by patient representative groups who had been major recipients of Biogen funds, and raised concerns that safeguards were insufficient to mitigate regulatory capture within the FDA. Here, we reflect on events leading to the FDA's decision on 7 June 2021 and consider whether any lessons can be learned for the field.