Biogen and Eisai unveil details for five-year, real-world Aduhelm clinical trial


Biogen and partner Eisai are pressing ahead to gather more data about their Alzheimer’s disease drug, Aduhelm, and they have now revealed plans for a 6,000 patient real-world study. To be clear, this study is not the confirmatory clinical trial required as a condition of the drug’s accelerated approval.

The observational study will enroll patients at about 200 sites in the U.S. over the course of four years. Those patients will be followed for up to five years to understand the drug and its effects as it is prescribed in routine clinical practice. The main goal of the study is to characterize and evaluate long-term changes in cognition, function, and the neuropsychiatric status of patients treated with Aduhelm. Biogen and Eisai announced the plans for the observational study at Alzheimer’s Association International Conference, which is being held this week both virtually and in Denver.

Aduhelm is an antibody drug designed to reduce levels of beta amyloid, a protein that builds up on the brains of Alzheimer’s patients. The intravenously infused drug won the regulatory nod in June under the agency’s accelerated approval pathway. That decision defied an FDA advisory panel’s vote against recommending approval, citing the drug’s failure in pivotal studies.

The aftermath of Adhuelm’s approval has sparked controversy on multiple fronts. Many in the scientific community bemoaned the approval despite the drug’s clinical trial failures. Others criticized the process, in which certain FDA officials reportedly discussed the drug’s application while the medicine was under regulatory review. Supporters of the drug criticized the Aduhelm’s $56,000 annual price. The initial approval, which was worded to suggest an indication broader than what was tested in clinical trials, led Cambridge, Massachusetts-based Biogen to seek an update to Aduhelm’s label clarifying that the drug should be prescribed to Alzheimer’s patients with mild cognitive impairment or mild dementia rather than to Alzheimer’s patients broadly.

Accelerated approval is a speedier decision based on a less evidence than is typically required in a drug application. As a condition for this type of approval, companies are required to provide additional post-marketing clinical data to confirm the drug’s benefit to patients. Biogen said the confirmatory study is still being designed.

Biogen said it aims to improve minority representation in the real-world study, setting a goal of having Black and Latinx patients represent at least 16% of the 6,000 clinical trial participants. A total of three clinical programs are planned for generating new data about Aduhelm. In addition to the real-world study and the confirmatory study, Biogen is conducting an ongoing Phase 3b re-dosing study. This clinical trial is enrolling eligible patients who previously participated in the Aduhelm clinical trials.

Photo: John Tlumacki/The Boston Globe, via Getty Images