The results of the trial support the notion that the drug must be administered early, said Dr. Paul Verhoeff, a clinician-scientist at the Kunin-Lunenfeld Applied Research Unit at Baycrest, a University of Toronto teaching hospital that specializes in studies of aging.
The Phase 2 trial found people with mild Alzheimer's who were on a high dose of the drug scored significantly better on tests gauging their functional abilities when compared to people on placebo. People on a lower dose of the drug or people with moderate Alzheimer's did not show the same benefit.
"There seems to be a magic window, again pointing out that you probably have to be there fairly early in the disease to get the maximum bang for your buck," Verhoeff said.
Neither Verhoeff nor Chertkow were involved in the study, which was paid for by tarenflurbil's manufacturer, Myriad Pharmaceuticals.
Even those who did show benefit didn't score higher on cognitive tests - tests in which they might have been asked to remember words or list as many animals as they could think of, for example. The gains seen related to their ability to function, a critical part of prolonging independent life.
"It means that people were continuing to be able to do the things that they started off being able to do, and they didn't lose their abilities as quickly as the patients on the lower dose or on placebo," Black said.
"So that would translate into somebody who might still be able to look after finances. Or somebody might still be able to drive. Or somebody might still be able to take part in hobbies. Or even do part time work - that sort of thing."
