The Food and Drug Administration approved the drug aducanumab to treat patients with Alzheimer’s disease on Monday morning. It is the first new drug approved by the agency for Alzheimer’s disease since 2003.
The drug is the first to show significant progress against the sticky brain plaques that are the hallmark of Alzheimer’s disease.
The drug has proved highly effective at reducing the plaques, called beta amyloid, that build up in the brains of people with Alzheimer’s.
But does the drug actually slow the progression of the disease when it reduces the plaques? It’s not yet clear. Two large studies offered conflicting evidence about whether the treatment slows declines in memory and thinking. A panel of expert advisers to the FDA recommended in November that the agency not approve the drug.
As a condition of approval, the FDA is requiring Biogen, the drug’s maker, to conduct another clinical study to confirm that the reduction of amyloid plaques results in clinical improvement for patients. If the subsequent study doesn’t show a clinical improvement, the agency could move to withdraw the approval.
There are also concerns that the FDA’s approval will make it difficult for Biogen and Eisai to find enough patients to participate in its next clinical trials, as patients might not want to risk getting the placebo and can get the drug without being in a study.
The medicine will be marketed under the trade name Aduhelm.
The FDA acknowledged the controversy and attention the drug’s approval has garnered from the Alzheimer’s patient community, elected officials and others.
The agency opted to put Aduhelm on the FDA’s accelerated approval pathway, which is meant to speed access to potentially valuable therapies for patients with serious diseases to serve an unmet need, and where a clinical benefit is expected — even if there is still some uncertainty about that benefit.