FDA Extends Review Period for Aducanumab  for Alzheimer Disease Treatment

The Food and Drug Administration (FDA) has extended the review period by 3 months for aducanumab (BIIB037; Biogen, Cambridge, MA) for Alzheimer disease (AD) treatment. The updated Prescription Drug User Fee Act (PDUFA) action date is June 7, 2021.

As previously reported in Practical Neurology, the application to the FDA for approval was based on data from the EMERGE (NCT02699463) and ENGAGE (NCT02477800) clinical trials, which were phase 3 multicenter randomized double-blind placebo-controlled parallel-group studies designed to evaluate the efficacy and safety of aducanumab. The studies evaluated the efficacy of monthly doses of aducanumab compared with placebo in reducing cognitive and functional impairment as measured by changes in the Clinical Dementia Rating-Sum of Boxes (CDR-SB) score. Secondary objectives were to assess the effect of monthly doses of aducanumab as compared with placebo on clinical decline. The EMERGE trial met the primary and secondary endpoint, the ENGAGE trial as a whole did not meet the prespecified primary endpoint. However, the post hoc analysis of a subset of participants in the ENGAGE trial provided supporting data for the EMERGE trial. 

Although the neurology advisory board to the FDA recommended against approval, the FDA has continued with the approval process and requested more information from the developers of aducanumab. The extension of the review period is response to that information request.

“We are committed to working with the FDA as it completes its review of the aducanumab application,” said Michel Vounatsos, chief executive officer at Biogen. “We want to thank the FDA for its continued diligence during the review.”