Physicians are warning against prescribing the controversial Alzheimer’s disease drug aducanumab for a related condition amid concerns of amyloid-related imaging abnormalities.
The U.S. Food and Drug Administration approved the controversial drug on June 7. Patients will require either an amyloid-positive PET scan or lumbar puncture to begin treatment. Baseline MRI scans are also mandatory to track disease progression.
But during trials testing aducanumab and other anti-amyloid drugs, MR imaging revealed high rates of major adverse events, including brain bleeding and swelling.
Leading experts say using this novel drug to treat patients with cerebral amyloid angiopathy (CAA)—a cerebrovascular condition similar to Alzheimer's—may trigger even more of these amyloid-related imaging abnormalities (ARIAs).
Massachusetts General Hospital doctors and members of the International Cerebral Amyloid Angiopathy Association (ICAAA) issued their warning letter Tuesday in The Lancet Neurology.
"We believe that there are substantial uncertainties and concerns about both the safety and efficacy of aducanumab in patients diagnosed with CAA [and] therefore believe [it] should not be used for the purpose of treating CAA outside the context of a research trial," Steven Greenberg, MD, PhD, director of the Hemorrhagic Stroke Research Program at MGH and president of the ICAAA, and co-authors advised.
Their concern stems from the way amyloid-beta forms in ICAAA patients compared to those with Alzheimer’s. In the former, deposits typically gather in the cerebral blood vessels, not the brain tissue itself, the experts noted. And these specific deposits are more resistant to aducanumab treatment, which could put patients at risk.
"We haven't taken a position on whether an Alzheimer's patient who also has markers of CAA should be prescribed aducanumab," Greenberg said in a statement. "What we are saying is that the drug shouldn't be prescribed for the purpose of treating CAA."
Read the full letter here.