Four cases
Of the 11 patients who were candidates for aducanumab treatment, four developed ARIA. All are APOE ε4 carriers, with two homozygotes and two heterozygotes. All had severe radiographic ARIA-E, with one developing ARIA-H.
“Importantly, they were all initially asymptomatic and the ARIA was just picked up on their regular surveillance MRI,” said Dr. Riddle. She added that the drug was discontinued in all four cases.
Three of the ARIA cases were detected prior to the 5th scan, which is “concerning,” said Dr. Riddle. “Based on the current FDA label of safety monitoring, they don’t recommend doing that MRI. So [clinicians] would have dosed through that ARIA, which could put someone at much greater risk of developing severe symptoms.”
In addition, 14 patients at the center are receiving treatment with aducanumab. However, at this point they have not yet received their first MRI screen.
Dr. Riddle noted that when patients are told they are not candidates for treatment, or when treatment is discontinued, they are upset. However, she added, there is also a substantial level of understanding.
“We have a very layered discussion that includes the simple fact that we still aren’t sure if this is going to provide any clinical benefit, that this decision [to approve the drug] was accelerated, and that data are still being gathered,” Dr. Riddle added.
Dr. Riddle noted that the risk of ARIA is highest during the dose titration period: “There’s a signal that once you get to the 10 mg/kg dose, that plateaus.”
None of the patients at her center have reached that 12-month treatment mark. “The current plan is to do the MRI at 12 months then to give serial MRIs but less frequently, and whether that’s at 6 months or annually is yet to be determined.”
“We’re kind of writing these protocols as information evolves,” Dr. Riddle said.
The Memory and Aging Program receives grants from NIH-ADNI, Alzheimer’s Association, Fain Family Foundation, Joukowsky Family Foundation, Winter Family, Rhode Island Foundation, Goodman Family Foundation, and Global Alzheimer Platform Foundation; and clinical trials include: Lilly, Biogen, Genentech, Avid, Roche, Eisai, and Novartis. Dr. Riddle has disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.