Biogen aims to file with the Food and Drug Administration for regulatory approval of aducanumab, an antibody under investigation for Alzheimer’s disease, in 2020 following largely positive results of a secondary analysis of two failed phase 3 trials, ENGAGE and EMERGE, the company announced Oct. 22.
Biogen’s plans reverse its March 21, 2019, decision with codeveloper Eisai to discontinue work on the drug after a futility analysis of the trials determined aducanumab was unlikely to yield significant benefit. Biogen announced the plan to file a biologic drug application following a new analysis of additional data that became available after the data lock on the futility analysis. But while primary and secondary endpoints were nearly all positive for EMERGE in the secondary analysis of the larger dataset, the same could not be said for the twin trial, ENGAGE, which had negative results for most of its endpoints. However, Biogen said that “results from a subset of patients in the phase 3 ENGAGE study who received sufficient exposure to high-dose aducanumab support the findings from EMERGE.”
Both the Alzheimer’s Association and researchers interpreted the announcement with a measured tone, saying it offered a hopeful sign for a field continually stymied in its quest for an effective treatment. More than 100 clinical trials have failed over the last 20 years.
Dr. Rebecca Edelmayer
“This really is very encouraging news,” Rebecca M. Edelmayer, PhD, director of scientific engagement at the Alzheimer’s Association, said in an interview. The secondary combined analyses showed “the largest reductions in clinical and functional decline we have seen. It’s an important moment for the patients with AD and their families, and for researchers all around the world. This deserves to be discussed and considered by the research community, but we really need to dig deep into the data. We expect to see more of them at the Clinical Trials on Alzheimer’s Disease conference,” which is set for early December.
Paul Aisen, MD, a consultant for Biogen and director of the Alzheimer’s Therapeutic Research Institute at the University of Southern California, Los Angeles, was similarly measured.
“There is an enormous amount of data here and they will be very challenging to interpret, especially since both trials were stopped in a futility analysis,” he said in an interview. “We’re now interpreting data that continue to be collected after the initial data lock. But I do believe there is evidence that supports the amyloid hypothesis and the development of aducanumab.”
A deep data dive is in order before the field completely embraces aducanumab’s advancement, agreed Michael Wolfe, PhD, the Mathias P. Mertes Professor of Medicinal Chemistry at the University of Kansas, Lawrence.
Dr. Michael Wolfe
“We would have to see exactly how they came up with this new data set and analysis. I have felt for many years now that these companies would try to parse and shuffle the data around until they got a statistically significant result, just to get approval. They would make billions per year but not really make a difference in people’s lives. That being said, if aducanumab truly slows the decline in activities of daily living, keeping people independent longer, that would be a worthwhile clinical result.”
Still to be considered is whether aducanumab could confer enough benefits to be worth monthly, potentially lifelong, infusions of a pricey medication that still won’t stop disease progression.
“Whether the clinical impact will be worth the anticipated cost remains to be seen,” Richard J. Caselli, MD, said in an interview. “This is likely to be a very expensive treatment for a subgroup of individuals with the hope of slowing decline, but – unless there is a huge upside surprise in data yet to be released – it is not going to halt progression and will certainly increase the cost of care dramatically.”
Dr. Richard J. Caselli
Dr. Caselli, clinical core director of the Alzheimer’s Disease Center at the Mayo Clinic in Phoenix, continued: “I imagine if approved, there will be a number of insurance obstacles to overcome regarding who qualifies, for how long, etc. Scientifically, this certainly supports the long-held view that beta amyloid is important in the pathophysiology of Alzheimer’s disease. But, again, unless the impact is unexpectedly huge, I don’t think this quiets those who feel there is more to the story than only a gain of beta amyloid toxicity, though this does support the idea that it plays a role, which should not surprise anyone.”
Dr. Edelmayer said the Alzheimer’s Association has raised the issue of access and cost with Biogen.
“We have had many discussions about their capacity to roll this out,” if aducanumab is approved, she said. “Those who were in the studies will be the first recipients. But Biogen is making plans to move this into the general population if approved, to all patients who meet the diagnostic criteria.”
“There is precedent out there when it comes to doing infusion medicines, and those centers are part of the planning process. In terms of pricing, this is a problem we would be happy to see, because it would mean that we have a treatment. But we’ll cross that bridge when we come to it.”