Diabetes Drug Shows Slight Effect on Dementia in Study

Older Germans who took Takeda Pharmaceutical Co.’s diabetes medicine Actos were slightly less likely to develop dementia, according to a study that may do little to resolve questions about the drug’s usefulness.

The German Center for Neurodegenerative Diseases followed 145,717 people of age 60 or older who were members of the country’s biggest public insurer from 2004 to 2010, tracking whether they developed dementia and also whether they took Actos, once the world’s best-selling diabetes medicine. Those on the drug were 6 percent less likely to develop dementia, according to results presented today at the Alzheimer’s Association International Conference in Copenhagen.

Doctors have long wondered whether Actos, known generically as pioglitazone, and another similar diabetes drug, Avandia, or rosiglitazone, might also work in the brain to stave off dementia. An Alzheimer’s study of Avandia failed, and problems with side effects plagued both drugs. Now Takeda is trying again with Alzheimer’s, in a five-year trial that started last August. Today’s data may not provide much encouragement, said Ben Wolozin, a professor at the Boston University Alzheimer’s Disease Center.

“It was very important to do this study,” Wolozin said in a telephone interview. “However, it’s actually almost surprising to me that the lowering of relative risk was so weak.” The 6 percent reduction seen in the study is such a small effect that it’s unlikely to translate into an observable difference in everyday practice, Wolozin said.

Even so, he said, Takeda is probably right to continue the study begun last year. Takeda’s study, dubbed Tommorrow, will compare pioglitazone with placebo tablets and will also see whether a genetic test can predict which patients are at risk of developing mild cognitive impairment due to Alzheimer’s.

“The benefits of a success are huge,” Wolozin said.

Takeda said its trial will probably keep enrolling patients for the next several months before it hits a target of 5,800 people. It’s on schedule, Stephan Brannan, the Osaka-based company’s head of central nervous system development, said by e-mail before today’s research was released.

The German research team declined to comment in advance of the study’s publication.

(Corrects fifth paragraph of article published July 14 to reflect company’s spelling of trial name.)
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