Three members of the FDA panel overseeing research have resigned since the approval this week, including Dr. Aaron Kesselheim, a professor of medicine at Harvard Medical School, who said in a letter the agency’s decision on Biogen “was probably the worst drug approval decision in recent U.S. history.”
CNBC’s article entitled “Biogen Alzheimer’s drug and the battle over dementia treatment of the future” reports that last November, in an 8-1 vote, that panel said Biogen’s late-stage study didn’t provide “strong evidence” showing that aducanumab effectively treated Alzheimer’s; two other panelists said that the data was “uncertain.”
While some experts see Aduhelm an “effective treatment” for a disease that affects millions of Americans, others have concerns about the FDA ruling’s implications for the panoply of other potential treatment options that are in late-stage development.
An immediate challenge facing other researchers working on a wider Alzheimer’s drug pipeline will be to keep participants in ongoing trials. In most cases, many Alzheimer’s sufferers will quit other drug studies to pursue treatment with the newly approved Aduhelm. This will make the trial data for those alternative drugs less useful, even though the drugs in question might one day prove safer, more effective, or more appropriate for different stages of the disease’s progression. Nonetheless, Aduhelm’s approval is seen by many as a big boost towards those efforts.
Some major drug companies stopped efforts to research brain diseases, including Pfizer and Boehringer Ingelheim in 2018. Biogen had given up on Aduhelm at one time in the clinical trials in 2019 before reversing its decision. This was after decades of failure in search of a breakthrough.
The National Institutes of Health spent two to three times more on heart disease and cancer research than on dementia in recent years, while a lack of qualified participants for clinical trials also slowed progress.
Aduhelm’s clinical trial data demonstrated that the drug successfully targets and clears out clusters of a specific type of protein that are thought to be responsible for Alzheimer’s. However, it gave insufficient evidence to prove the drug provides patients with cognitive benefits. Known among scientists as aducanumab, it works by offering an array of identical antibodies that are cloned from white blood cells. These antibodies are chosen for their targeting abilities, since they can identify specific proteins, called beta amyloids, that have constructed particular formations in the body. There’s extensive evidence suggesting that these beta amyloid formations, also known as “pathological aggregates” or “plaques,” are a major driver of Alzheimer’s disease, though the exact causal mechanisms are still not fully understood.
“What we’re going to find out from the use of this drug one way or the other, is whether or not the amyloid clearing hypothesis is correct,” says USC health economist Darius Lakdawalla, who argues the continued trialing of Biogen’s drug will prove useful to that confirmatory effort.
“If it is correct, then I think it opens the door for a lot of innovation, a lot of drug candidates that are going to try to clear amyloid in the future pursuit of that hypothesis.”
Reference: CNBC (June 12, 2021) “Biogen Alzheimer’s drug and the battle over dementia treatment of the future”