The safety of the oral diabetes drug Actos has been increasingly questioned as research has linked the drug to bladder cancer. Pharmaceutical product liability litigation surrounding Actos jumped markedly in the past few years as more patients began developing bladder cancer and other serious side effects.

Actos, also known as pioglitazone, was introduced to the U.S. market by Takeda Pharmaceutical Co. and Eli Lilly. The companies jointly marketed and sold the blockbuster drug until around 2006. Actos belongs to a class of drugs called thiazolidinediones, which were all introduced in the late 1990s. Many thiazolidinediones have been linked to serious side effects, including heart disease, heart attacks and, in the case of Actos, bladder cancer.

The U.S. Food and Drug Administration issued a warning regarding Actos in the summer of 2011. The FDA specifically warned patients that using Actos for more than one year was associated with an increased risk of bladder cancer. The FDA’s safety announcement was based on the agency’s review of a 10-year epidemiological study.

“The five-year results showed that although there was no overall increased risk of bladder cancer with pioglitazone use, an increased risk of bladder cancer was noted among patients with the longest exposure to pioglitazone and in those exposed to the highest cumulative dose of pioglitazone,” the FDA said.

Research published in the journal Diabetes Care also confirmed the link between Actos and bladder cancer. Researchers evaluating FDA adverse events reports found that Actos patients experienced a threefold increase in bladder cancer incidents based on their reporting odds ratio. The European Medicines Agency also called for more study into the safety of Actos after noticing a flood of bladder cancer reports.

Although the FDA did little more than strengthen the label warnings for Actos, authorities in Germany and France pulled the dangerous pharmaceutical from store shelves.

For its part, Takeda, the manufacturer of Actos, denies the link between Actos and bladder cancer, going so far as to suggest that Actos may actually prevent bladder cancer. The company’s claim is based on a 2009 re-evaluation of a 2005 study into the side effects of Actos.

Researchers from the American Association for Justice have noted that the Takeda study was flawed and that independent re-evaluations of the Takeda research have confirmed the link between the drug and bladder cancer.

“A significant weakness of the 2005 study is the exclusion of patients merely because they had one or more risk factors for bladder cancer,” AAJ researchers said.

Patients who have taken Actos may be at a continued risk for developing bladder cancer. Actos users should consult with their doctors regarding their diabetes treatment options and contact an experienced pharmaceutical litigation law firm if they are diagnosed with bladder cancer.

Source: American Association for Justice, “Bad Actos,” 48-JUN Trial 20, Howard L. Nations, John M. Restaino, 2012