Eleven patients have died while taking Alzheimer’s disease drug Aricept during a clinical trial, Japan’s Eisai Co., which makes the medicine, said Thursday.
There were no deaths among patients who were taking a placebo, said Eisai, which markets Aricept with Pfizer Inc.
The drug, which treats mild to moderate Alzheimer’s disease, was being tested in patients with vascular dementia, the second most common form of dementia after Alzheimer’s disease.
Applications to expand the use of Aricept to vascular dementia, which is caused by a stroke or diseased blood vessels, are pending in both the United States and Europe, said Eisai spokeswoman Judee Shuler.
“We are still working with the FDA (U.S. Food and Drug Administration), discussing it,” she said.
Shuler said she could not comment on how the results might affect the status of Aricept. Pfizer officials were not immediately available.
Aricept is approved for vascular dementia in a half-dozen smaller markets, including South Korea and India.
The deaths were among 648 patients who received Aricept once daily for 24 weeks. That compared with no deaths in the 326 patients receiving placebos, Eisai said in a release.
The difference in mortality between the groups was statistically significant, meaning it probably was not due to chance.
The trial is a Phase 3 study, the final period of testing before companies present proposals to regulators for approval.
Improvement in cognitive function
It was conducted in nine countries and involved only patients with vascular dementia, with no prior diagnosis of Alzheimer’s disease. Most had a history of stroke or heart disease, and were therefore also taking medicines to treat their cardiovascular problems.
Eisai said it had not expected the absence of deaths in the placebo group, considering the age and sickness of patients in the study. By contrast, the company said there had been a combined 2 percent incidence of death among patients taking placebos in two prior vascular dementia trials.
The incidence of death in the Aricept group was similar to that in prior trials. But in these earlier studies, the difference between placebo deaths were not statistically significant.
Patients taking Aricept in the latest trial showed a statistically significant improvement in cognitive function, compared with those taking placebos. But the Aricept group showed no significant benefit on another primary measure of the trial, known as global function.
