Pioglitazone (Actos°) was authorised in 2000 by the European Medicines Agency for diabetic patients. The application already revealed a risk of bladder cancer that had been observed in animals, and Prescrire advised right away against using this drug.

In 2006, the US Food and Drug Administration (FDA) revised the Summary of Product Characteristics (SPC) for Actos° in order to include worrying human data regarding bladder cancer.

Nonetheless as of mid-2011, the European SPC for Actos° still says nothing about the data observed in humans.

In January 2011, Prescrire requested pharmacovigilance data from the European Medicines Agency regarding the bladder cancer risk. It took EMA two months to get back to Prescrire with basic information explaining the studies underway, but with no details whatsoever on the cases of cancer reported.

Prescrire's experience in requesting information from EMA is both long and disappointing (5 complaints filed for EMA's refusal to provide information are currently pending with the European Union Ombudsman). Prescrire sent a second request to the Agency, having interpreted the initial response as a veiled refusal to provide information. EMA confirmed this refusal in May 2011, citing a reason often given: the fact that a re-evaluation is currently underway.

At the same time, the French medicines agency (Afssaps) replied to Prescrire with information on 3 reports of bladder cancer. The French agency also requested a study from France's national health insurance system (Cnamts), which confirmed "that the use of pioglitazone causes a slight increase in the risk of bladder cancer". This finally led Afssaps to decide in June 2011 to suspend the use of pioglitazone in France.

The French medicines agency is starting to draw lessons from the Mediator° scandal, to the benefit of patients. Their decisions are still slow, but a promising change in attitude is discernable. On its end, EMA continues to turn a deaf ear. The Agency is keeping Actos° on the market, a drug that is more dangerous than it is useful, to the detriment of patients, and all the while refusing to provide the data in its possession to an independent editorial team.

It is time that the European Commission firmly redirects EMA back to its mission of protecting the public, in particular by insisting on a major clean-up in the Agency's conflicts of interest with pharmaceutical companies.

©Prescrire 6 July 2011