Dr Salloway, a site principal investigator for the drug’s trials, was not paid for this work but received research and consulting fees from Biogen. He said doctors should only use the drug for patients whose status matches that of clinical trials.
“There is no evidence that this could be beneficial for any other stage of Alzheimer’s disease,” he said.
Mary Sano, director of Mount Sinai Alzheimer’s Disease Research Center in New York City, said the criteria she and other panelists described were “very important” and meant “this is going to be very restrictive and the ability to share what drug with a wide range of people will be drastically limited, at least for now. “
Treating only people with mild symptoms would mean that for dementia clinicians, “most of your staff in your current practice are probably not eligible,” said Dr Sano.
In its decision, the FDA acknowledged that there was not the standard of proof of benefits that the agency requires. As a result, he makes Aduhelm available through a program called expedited approval, citing the drug’s ability to reduce amyloid levels in the brain. But reducing amyloid is not the same as slowing the symptoms of dementia. Many amyloid-reducing drugs have failed to slow the decline in clinical trials, a story that makes some experts particularly reluctant to trust Aduhelm based on the evidence produced so far.
Given the agency’s focus on amyloid in its approval decision and the fact that all clinical trial participants were required to have high levels of amyloid, experts were also surprised that the label FDA does not require that patients be tested for the protein. Doctors at the Alzheimer’s Association forum all said that high levels of amyloid, usually measured by PET or lumbar puncture, should be a condition of treatment.
Several of the panelists said that at least initially, relatively few physicians and clinics would have the capacity to adequately diagnose, screen and treat patients.
“It’s not a simple drug to use,” said Dr. Paul Aisen, director of the Alzheimer’s Therapeutic Research Institute at the University of Southern California and co-author of a article urging the FDA to approve the drug. “I believe that establishing the right people for treatment and monitoring treatment requires knowledge and benefits from experience, and there are very few clinicians who have that experience.”