Medivation Alzheimer's drug helps -- if used early

By Julie Steenhuysen
31 july 2008--A drug for Alzheimer's disease made by Medivation Inc kept symptoms at bay for 18 months, U.S. researchers said on Wednesday, but people who got the drug after first taking a placebo fared less well, suggesting early treatment is best.
The latest results, being presented at the Alzheimer's Association's international meeting in Chicago, found Dimebon was safe and continued to benefit people who took it for a year and a half.
"The most important thing from my point of view is there were no new safety issues that emerged with longer exposure of the patients," said Dr. Jeffrey Cummings of UCLA, who helped with the study.
The results from the 183-patient study conducted in Russia found people continued to improve, with benefits seen in cognition, memory, activities of daily living and behavior.
The study also found that people who were treated with a placebo for a year and then took Dimebon stabilized across five measures of thinking ability, but were unable to catch up to the group who had taken it for the full 18 months.
"People initially treated with the placebo and then crossed over to Dimebon did not show the same level of benefit as those people who took Dimebon for the full 18 months," Cummings said in a statement.
"This emphasizes the benefit of earlier treatment and suggests the possibility that Dimebon may slow the progress of Alzheimer's," he said.
Medivation has provided frequent updates of patients in the study in Russia, where patients in the study took few if any drugs other than Dimebon.
Such a study would not be possible in Western countries, where most Alzheimer's patients take a variety of other drugs.
Some doctors think the true test of whether Dimebon represents an advance over current therapies will come from studies done in the West, where patients have ready access to other drugs that can slow progression of the disease.
These include Eisai Co Ltd's and Pfizer Inc's Aricept, Forest Laboratories Inc's Namenda, Novartis AG's Exelon and Johnson & Johnson's Razadyne.
All affect message-carrying chemicals in the brain called neurotransmitters, but lose their effect over time.
"The one issue with this trial is that no other treatments were allowed," Dr. Scott Turner, incoming director of the Memory Disorders Program at Georgetown University Medical Center in Washington, said in a telephone interview.
"Here it will be tested as an add-on, and the question is will it have any other benefit (when taken) with the current therapies," he said. "I think that is a big if."
Cummings thinks the drug has a shot.
"I think we will continue to see an effect because the signal was strong; but under the circumstances of a global trial, it will likely be not as clearly seen as it was in the Russian trial," he said in a telephone interview.