Sanofi investigated over epilepsy drug linked to birth defects

French healthcare company Sanofi said on Tuesday it was being investigated over Depakine, an epilepsy drug which caused birth malfunctions and slow neurological development when taken during pregnancy.

The Paris prosecutor launched a preliminary investigation into the authorization and marketing of Depakine in October 2016 after French social affairs inspection agency IGAS criticized the slow response of French health authorities and Sanofi over the risks related to the drug and its derivatives.

Sanofi said in a statement that the indictment will allow it to defend itself and to "prove it has always complied with its to duty to inform and been transparent".

Sodium valproate, the active molecule in the drug, has been on the market since 1967 to treat epilepsy and bipolar disorder. It features on the World Health Organization's (WHO) list of "essential medicines".

IGAS estimated that between 2006 and 2014, 425 to 450 babies suffered congenital birth defects or were stillborn following exposure to Depakine.

Marine Martin, president of victims association APESAC, said on Twitter she was "extremely satisfied to see the criminal proceedings she launched in 2016 reach an important threshold".

"Sanofi will have to deal with the tens of thousands of poisoned victims, out of which more than a hundred died".

The French firm become aware of the risk of fetus malformation in the 1980s and then, around 2003, of the drug's impact on the neurological development of the fetus, with a risk of autism or learning difficulties.

Sanofi, which in January 2019 said that it would not take part in any compensation for Depakine, added it would continue to "fully cooperate with the judicial authorities", and was "confident" over the outcome of the procedure.

Its shares were up 0.6% at 09h00 GMT on the Paris stock market, broadly in line with the pharmaceutical sector .SXDP.