Health authorities in France denying keeping the lid on a study said to show that the anti-convulsive drug Depakine, produced by drugmaker Sanofi and used to treat epilepsy, caused birth defects over a period of eight years. The weekly newspaper Le Canard Enchainé reported that the drug based on sodium valproate was prescribed by physicians to more than 10,000 pregnant women in France between 2006 and 2014, at a time when the potential risks for their unborn children were already known.

In a response published on Aug. 10, the ministry said initial findings of the study launched a year ago by national drug agency ANSM and health insurance agency CNAMTS will be presented as scheduled on Aug. 24 to parents whose children were affected. An „action plan“ of measures needed to be taken is to be made public in September.

In another study, published in February of this year, the French social affairs inspection agency IGAS estimated that as many as 450 children exposed to the drug during their mother’ pregnanc were stillborn or suffered congenital defects. Reports said the agency had criticized the slow response of French health authorities and Sanofi to the findings.

A Sanofi spokesperson told the news agency Reuters the company was not aware of the data contained in the studies; however, the risk of the drug causing fetus malformation were identified in the 1980s and later its impact on the unborn child’s neurological development became known. The risks, it said, had been spelled out in the drug's documentation – approved by French health authorities – since 2006.

Depakine has been on the market since 1967. In addition to the Sanofi-branded formulation, a generic product is also sold. According to Reuters, the Paris prosecutor launched a preliminary investigation into the authorization and marketing of the drug in October 2015.