Two recent studies this year show a stronger link between Actos, a drug used in treating Type 2 diabetes, and bladder cancer.
In May, a study published in the British Medical Journal showed that using Actos for two years would double a patient’s risk of bladder cancer. A study published in the July edition of the Canadian Medical Association Journal showed that taking Actos (pioglitazone) increased the risk of bladder cancer by about one-fifth. However, researchers on the second study state that the individual risk of bladder cancer remains low.
On WebMD, researcher Laurent Azoulay, an epidemiologist at Lady Davis Institute of Jewish General Hospital in Montreal, says of the study in the BMJ: “Patients with type 2 diabetes and their physicians need to be fully aware of the potential association between Actos and bladder cancer … Certainly, this drug should not be used in patients with a history of bladder cancer and those with other bladder conditions.”
Spyros Mezitis, MD, an endocrinologist at Lenox Hill Hospital in New York, told WebMD, “We need to be careful when starting patients on Actos, and we should be checking for bladder cancer in urine samples among the ones who are already taking it.”
The May study, at McGill University in Montreal, focused on diabetes patients who had been treated with any diabetes drug between 1988 and 2009. Out of 115,000 people studied, 470 were diagnosed with bladder cancer in about 4 years of follow-up treatment. Risk of bladder cancer increased when Actos (pioglitazone) was taken for 2 or more years, and when patients took higher doses of the drug.
However, according to this study, Avandia (rosiglitazone) carried no increased risk of bladder cancer. Avandia is in the same drug class as Actos, and is often studied alongside Actos to compare side effects.
After the results of this study were published in the BMJ, Takeda Pharmaceuticals, the company that manufactures Actos, released a statement about its drug:
“Takeda is confident in the therapeutic benefits of Actos and its importance as a treatment for type 2 diabetes. As a science and evidence-based company, Takeda firmly stands behind the substantial data available confirming the positive risk/benefit profile of Actos, which includes more than 12 years of clinical and patient experience with the product.”
In the July study, study senior author Jeffrey A. Johnson noted that, even with a 22% increase in risk, the incidence of bladder cancer is still low when using Actos. While researchers are not yet sure how Actos increases the risk of bladder cancer, Johnson pointed to animal studies which suggested the drug could cause crystals to form in the bladder, which could play a role in forming tumors.
Patients diagnosed with Type 2 diabetes have a 40% increased chance of developing bladder cancer due to the nature of the disease, and unrelated to prescribed drugs they take. Dr. Joel Zonszein, director of the clinical diabetes center at Montefiore Medical Center in New York City, says of many Actos studies that “there may be a population bias” because many patients with Type 2 diabetes are older and have had the disease for awhile. Some of the studies conducted on Actos do not take these risk factors into account, along with risk factors like being overweight and a smoker.
Last year, several individual lawsuits were consolidated in Louisiana under the title MDL 2299, with presiding Judge Rebecca Doherty. She has recently extended the deadline to submit injury claims in this trial. If you are in South Carolina, and you or a loved one may have developed bladder cancer after taking Actos, contact the experienced lawyers at Strom Law Firm, LLC. We offer free consultations to review the facts of your case, and advise you in the best way to proceed.