An announcement by drug manufacturer, Biogen that it plans to seek approval from the US Food and Drug Administration (FDA) for its Alzheimer treatment, aducanumab has rekindled hope for millions of people with early Alzheimer disease that it could reduce clinical decline.

According to the company and its Japanese partner, Eisai a new analysis of a larger dataset from its Phase 3 EMERGE study suggested that patients who received greater exposure to high doses of the drug experienced significant benefits on measures of cognition and function such as memory, orientation, and language. Patients also experienced benefits on activities of daily living including conducting personal finances, performing household chores such as cleaning, shopping, and doing laundry, and independently traveling out of the home.

“If approved, aducanumab would become the first therapy to reduce the clinical decline of Alzheimer’s disease and would also be the first therapy to demonstrate that removing amyloid beta resulted in better clinical outcomes,” Biogen says in a statement.

The decision to apply for FDA approval came as a surprise after Biogen and Eisai ended two-late stage trials (EMERGE and ENGAGE) of aducanumab in March this year after a so-called “futility analysis” suggested that the drug would fall short of its targets.

Source: http://investors.biogen.com/news-releases/news-release-details/biogen-plans-regulatory-filing-aducanumab-alzheimers-disease

However in a statement, Biogen says a new analysis of a larger dataset that became available after the pre-specified futility analysis shows that aducanumab is pharmacologically and clinically active as determined by dose-dependent effects in reducing brain amyloid and in reducing clinical decline as assessed by the pre-specified primary endpoint Clinical Dementia Rating-Sum of Boxes (CDR-SB). In both studies, the safety and tolerability profile of aducanumab was consistent with prior studies of aducanumab, the company states.

“With such a devastating disease that affects tens of millions worldwide, today’s announcement is truly heartening in the fight against Alzheimer’s. This is the result of groundbreaking research and is a testament to Biogen’s steadfast determination to follow the science and do the right thing for patients,” said Michel Vounatsos, Chief Executive Officer at Biogen. “We are hopeful about the prospect of offering patients the first therapy to reduce the clinical decline of Alzheimer’s disease and the potential implication of these results for similar approaches targeting amyloid beta.”

Study Results
EMERGE (1638 patients) and ENGAGE (1647 patients) were Phase 3 multicentre, randomised, double-blind, placebo-controlled, parallel-group studies designed to evaluate the efficacy and safety of two dosing regimens of aducanumab. The futility analysis was based on data available as of December 26, 2018, from 1748 patients who had the opportunity to complete the 18-month study period and predicted that both studies were unlikely to meet their primary endpoint upon completion.

Following the discontinuation of EMERGE and ENGAGE, additional data from these studies became available resulting in a larger dataset, which included a total of 3285 patients, 2066 of whom had the opportunity to complete the full 18 months of treatment. A new extensive analysis of this larger dataset showed a different outcome than the outcome predicted by the futility analysis. Specifically, the new analysis of this larger dataset showed EMERGE to be statistically significant on the pre-specified primary endpoint (P=0.01). Biogen believes that data from a subset of ENGAGE support the findings from EMERGE, though ENGAGE did not meet its primary endpoint. Biogen consulted with external advisors and the FDA on these different results and their implications.

“This large dataset represents the first time a Phase 3 study has demonstrated that clearance of aggregated amyloid beta can reduce the clinical decline of Alzheimer’s disease, providing new hope for the medical community, the patients, and their families,” said Dr. Anton Porsteinsson, William B. and Sheila Konar Professor of Psychiatry, Neurology and Neuroscience, director of the University of Rochester Alzheimer’s Disease Care, Research and Education Program (AD-CARE), and principal investigator.

Biogen says after reviewing the data in consultation with the FDA, it believes that the difference between the results of the new analysis of the larger dataset and the outcome predicted by the futility analysis was largely due to patients’ greater exposure to high dose aducanumab. Multiple factors contributed to the greater exposure to aducanumab in the new analysis of the larger dataset, including data on a greater number of patients, a longer average duration of exposure to high dose, the timing of protocol amendments that allowed a greater proportion of patients to receive high dose, and the timing and pre-specified criteria of the futility analysis.