Despite availability of the dextromethorphan plus quinidine formulation, clinicians should avoid using it to treat agitation in Alzheimer’s disease patients until data become available from phase III studies that involve at least 6 months of chronic therapy, Dr. Cummings said. “We don’t want to encourage off-label use of the combined formulation until we understand it better when treating agitation in Alzheimer’s disease,” he cautioned.
He also highlighted the difficulty in enrolling Alzheimer’s disease patients with agitation as a significant symptom into trials, which means that completing a phase III trial could take perhaps as long as 2 more years and that FDA approval of this indication could be as long as 3 years off.
The study was sponsored by Avanir, the company that markets Nuedexta. Dr. Cummings has been a consultant to and has received honoraria from Avanir as well as from several other drug companies. He also owns stock or stock options in several companies developing drugs or other products aimed at Alzheimer’s disease patients. Dr. Sano has been a consultant to Eisai, Eli Lilly, and Takeda. Dr. Doody has been a principal investigator for trials sponsored by Avanir and several other drug companies. She also has been a consultant to several drug companies.
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