Plaintiffs continue to file lawsuits over the type 2 diabetes drug Actos (pioglitazone), alleging they were never warned about the risk of bladder cancer. More than 4,500 lawsuits have been consolidated in a federal multidistrict litigation (MDL) in the U.S. District Court for the Western District of Louisiana.
The U.S. Food and Drug Administration (FDA) approved Actos in 1999. The drug was developed by Takeda and Eli Lilly, but is now solely marketed by Takeda in the United States. Lawsuits filed over Actos allege that the drug makers failed to adequately warn about the risk of bladder cancer. Plaintiffs cite a number of studies and FDA warnings.
In 2010, the FDA said that use of Actos was associated with an increased risk of bladder cancer after two years of use. The findings were from an ongoing, ten-year epidemiological study. At the time, the FDA said it had not concluded that Actos increased the risk of bladder cancer. The agency issued another safety announcement in June 2011, stating that use of Actos for more than one year may be linked with an increased risk of bladder cancer. At around the same time, use of Actos was suspended in France and Germany; the ban was based on a French study suggesting a link between Actos and bladder cancer.
The FDA announced updated warning labels on Actos in August 2011, warning that use of Actos for one year or longer may be associated with an increased risk of bladder cancer.
A study published in JAMA showed that there was no significantly increased risk of bladder cancer among Actos users. Researchers found that a small increased risk cannot be excluded. The study was funded by a grant from Takeda.
Another recent study published in the BMJ showed that Actos is linked to a 63 percent increased risk of bladder cancer. Researchers found that this risk was only associated with Actos and not rosiglitazone (brand name: Avandia), a similar drug in the same class. The risk increased with increasing dosage and duration of use, researchers found. Funding was by the Canadian Institutes of Health Research.