In an unusual twist, a health insurance company has joined the Actos bladder cancer side effects consolidated litigation in federal court, as Blue Cross and Blue Shield of Massachusetts filed an Actos lawsuit alleging that Takeda Pharmaceuticals should pay for the medical bills incurred by members who suffered side effects.

There are hundreds of Actos lawsuits alleging that the Japanese drug maker failed to adequately inform patients of the possibility of cancer while taking the popular type-2 diabetes drug. The insurers note in the complaint that “as a result of the defective nature of Actos, persons who were prescribed and ingested Actos for more than 12 months, including plaintiffs’ insured, have suffered and may continue to suffer from bladder cancer.”

In fact, the Actos complications lawsuits allege that prior to approval in 1999, animal testing resulted in data suggesting that at similar blood serum levels, subjects were more likely to develop tumors. Six years later, unpublished results from a clinical trial regarding cardiovascular concerns also demonstrated the same problem, as did a longer study on liver damage, according to an Actos bladder cancer lawsuit.

Despite that, the company continued to claim that was inaccurate, although a 2011 study noted that reviewing the U.S Food and Drug Administration’s adverse events database, it “is consistent with association between pioglitazone and bladder cancer. This issue needs constant epidemiologic surveillance and urgent definition by more specific studies.”

The Actos Bladder Cancer Lawsuit is Blue Cross and Blue Shield of Massachusetts Inc. and Blue Cross and Blue Shield of Massachusetts HMO Blue Inc. v. Takeda Pharmaceuticals Inc., Case No. 14-cv-01149, in the U.S. District Court for the Western District of Louisiana.