Prolonged Use of Diabetes Drug Actos May Increase Risk of Bladder Cancer

The FDA announced that the prolonged use of pioglitazone (Actos), a medication used to treat type 2 diabetes mellitus, for more than 1 year has been linked to an increased risk of bladder cancer. The FDA is recommending that healthcare professionals tell patients with active bladder cancer not to take pioglitazone.

The FDA based its decision on a 5-year interim review of an ongoing 10-year epidemiological study. Although these results indicated that patients taking the drug were not at an overall increased risk of bladder cancer, those who either experienced the highest cumulative dose of pioglitazone or were taking the drug for the longest period of time were at an increased risk of bladder cancer.

The FDA’s recommendation is based on data showing that compared with those who had never been exposed to pioglitazone, patients who had received the drug for >1 year had a 40% increased risk of bladder cancer (hazard ratio [HR], 1.4; 95% confidence interval [CI], 0.9-2.1). The French study showed a statistically significant increase in the risk for bladder cancer in those taking pioglitazone compared with other antidiabetic medications (HR, 1.22; 95% CI, 1.03-1.43).

The news has already caught the attention of international authorities and has triggered suspensions of the drug overseas. In France, the Agence Francaise De Securite Sanitaire Des Produits De Sante (AFSSAPS), the French equivalent of the FDA, will suspend use of all medicines that contain pioglitazone as of July 11. The French had conducted their own epidemiological study of patients taking antidiabetic medications between 2006 and 2009. Takeda Pharmaceutical Company Ltd is the manufacturer of Actos and Competact (metformin and pioglitazone), another antidiabetic drug that is similarly affected by the suspension. Currently, 230,000 people are taking these drugs in France.

In March, the European Medicines Agency (EMEA) began an evaluation of medications that contain pioglitazone. The EMEA will also assess the French study’s results and determine how the data may impact the use of these medications throughout the European Union. Germany has recommended that pioglitazone not be started in new patients.

Takeda Pharmaceuticals said it will add this information to the “Warnings and Precautions” labels of its pioglitazone-containing medications. The company’s stock price has dropped since these study data were announced.