The Paris public prosecutor's office announced the investigation today.
It said while the death and injuries that occured could have been the result of pre-existing medical conditions the men involved had been suffering, it decided to examine if “criminal offenses" had contributed.
Investigations conducted since the trial was halted in January show the drug the injured men received - BIA 10 2074 - was not adulterated and was given in the dosages specified in the ANSM-approved protocol.
A defendant in the case was not named.
Biotrial told us “This is a normal decision, which was expected as part of a complex investigation that requires expertise and investigations abroad. As we have done since the first day of the administrative and judicial investigations, we will continue to cooperate in the utmost transparency with investigators.
"The judicial investigation guarantees respect for the adversarial principle and the rights of people, which are highly valued. We are convinced that Justice alone will make the truth about this dramatic accident, truth which is owed to the victims and their families, but also to all the Biotrial staff.”
One man died and five others were hospitalised during the study of Portuguese drug firm Bial-Portela & Ca. SA's anxiety treatment candidate - BIA 10 2074 - in January.
Last month, investigators from France's social affairs inspectorate (IGAS) criticised CRO Biotrial over how it conducted the Phase I study in a report (here – in French).
Failings cited by IGAS included that Biotrial continued to administer the drug to volunteers after the first member of the group was sent to hospital and that it failed to confirm patient consent.