According to news reports, thiazolidinediones -- pioglitazone and rosiglitazone (Avandia) are under the scrutiny of the FDA. The agency is looking into a probable connection between pioglitazone (Actos) and bladder cancer. After it got preliminary information from a 10-year epidemiological study that was funded by Takeda, the FDA started its investigation to evaluate pioglitazone.

After conducting a short-term study from the data that entailed over 193,000 patients suffering from type 2 diabetes, it was found that there was hardly any rise in bladder cancer amongst patients who took pioglitazone, than the ones who did not use pioglitazone.

However, it was seen that increased dosage and continued usage might boost the possibility of bladder cancer, with statistical significance rising after 24 months of use.

Today, Robert Spanheimer, MD, Takeda's Medical Director for pioglitazone told MedPage that the FDA declaration and the data from the epidemiological study should be "interpreted in the context of being interim results from a
10-year study".

The FDA wrote in its declaration of the safety review, "Results from two, three-year controlled clinical studies of Actos (the PROactive study and a liver safety study) demonstrated a higher percentage of bladder cancer cases in patients receiving Actos versus comparators".

The results of the PROactive study are incorporated in the present pioglitazone label in the "Precautions -- Carcinogenesis, Mutagenesis, Impairment of Fertility" segment.