The FDA’s approval of the Biogen-Eisai drug, aducanumab, marks a milestone achievement in Alzheimer’s disease research. This drug is the first approved treatment shown to slow progression of this disease. It is also a reflection of the years of research and momentum we see in Alzheimer’s research more broadly.
FDA approved aducanumab to treat patients with Alzheimer’s using the Accelerated Approval pathway, under which the agency “approves a drug for a serious or life-threatening illness that may provide meaningful therapeutic benefit over existing treatments when the drug is shown to have an effect on a surrogate endpoint that is reasonably likely to predict a clinical benefit to patients and there remains some uncertainty about the drug’s clinical benefit.” FDA further stated that “at the end of the day, we followed our usual course of action when making regulatory decisions in situations where the data are not straightforward.”
The FDA also stated that “approval is based on a surrogate or intermediate clinical endpoint (in this case reduction of amyloid plaque in the brain).” Additionally, “drug companies are required to conduct post-approval studies to verify the anticipated clinical benefit. These studies are known as phase 4 confirmatory trials. If the confirmatory trial does not verify the drug’s anticipated clinical benefit, FDA has regulatory procedures in place that could lead to removing the drug from the market.”