The use of the drug idalopirdine for six months did not improve or reduce the loss of cognition for patients with mild to moderate Alzheimer disease according to research published in JAMA.

Two phase 2 trials have suggested that a certain type of drug, a selective 5-hydroxytryptamine-6 receptor antagonist, such as idalopirdine, may improve cognition in Alzheimer disease when added with another type of drug, cholinesterase inhibitors.

Researchers conducted three randomized clinical trials, in which patients were assigned to receive idalopirdine or placebo added to a cholinesterase inhibitor. They included 2,525 trial participants, ages 50 years or older with mild to moderate Alzheimer disease from October 2013 to January 2017.  The researchers measured changes in cognition from study entry to 24 weeks.

Alireza Atri, M.D., Ph.D., of California Pacific Medical Center, San Francisco, and Brigham and Women's Hospital/Harvard Medical School, Boston, was lead author of the study.

Six months of idalopirdine treatment added to cholinesterase inhibitor therapy did not improve cognition or decrease cognitive loss in patients with mild to moderate Alzheimer disease. These findings do not support the use of idalopirdine for the treatment of Alzheimer disease.

There was no requirement for evidence of Alzheimer disease biomarker positivity for inclusion in a trial, which may have allowed some patients to be included without having Alzheimer disease pathology.