On June 15, 2011, the FDA issued a Drug Safety Warning with regards to an increased bladder cancer risk associated with the use of the diabetes drug, Actos.
This warning came after a review of data from a five-year interim analysis of an ongoing study of Actos by Takeda.
In the same year, Takeda was named in more than 10,000 Actos-related lawsuits.
The results showed that although there was no increased risk of bladder cancer among Actos users overall, there was an increased risk of bladder cancer amongst those who had used the drug the longest.
Independent researchers discovered that Actos users have a 40% higher chance of developing cancer after they have taken the drug for longer than a year.
There was also a greater risk of bladder cancer among Actos users who had been exposed to the highest cumulative dose of the drug.
Before the FDA warning – several European Markets, France and Germany, suspended the use of Actos, citing concerns over an increased risk of patients developing bladder cancer.
Studies continued to point toward Actos bladder cancer risks.
On July 5, 2013, an international independent study was published finding Actos to be “probably carcinogenic.”
In June 2013, 23 experts from nine countries met at the International Agency for Research on Cancer (IARC) to assess the carcinogenicity of fourteen drugs and herbal products.
After a detailed review of one large randomized controlled study, four cohort studies, and three case-controlled studies, the Agency determined that pioglitazone (the active ingredient in Actos) should be classified as “probably carcinogenic” to humans based on the evidence that it causes bladder cancer.
Takeda had profited from sales of Actos in the U.S. of over $3 billion in 2009 and just under $3 billion in 2010.