In April, U.S. scientists reported that short term use of the popular diabetes drug, Actos (pioglitazone), posed no risk of bladder cancer, while use for more than two years was only weakly associated with an increased risk.

But last month a French study found diabetics who used Actos for longer than 12 months were exposed to a 40 percent increase in risk for bladder cancer compared to diabetics who had never used Actos.

In a footnote to their study the U.S. scientists admit:

  • The study was funded by a grant from Takeda the manufacturer of the Actos. 
  • Takeda reviewed and commented on the study before it was submitted for publication.
  • The scientists are paid consultants of Takeda, as well as, other drug manufacturers GlaxoSmithKline and the Actos distributor Eli Lily. 

When the U.S. study was published the U.S. Food and Drug Administration did not take any action against Actos or its manufacturer Takeda.

But, when the French study was published, France and Germany pulled Actos from the market.  In response to the French study, the FDA issued a warning to consumers that Actos may increase the risk of bladder cancer when used for more than a year.

Did the funding from the drug manufacturers influence the results of the U.S. study?  It sure looks that way. How did the French study uncover such a strong association of risk of bladder cancer, when the U.S. researchers missed it?