A landmark criminal trial opened in Paris on Monday to decide whether one of the country's biggest pharmaceutical companies is responsible for the deaths of hundreds of people.
Servier Laboratories, the National Agency for the Safety of Medicines (ANSM) and 21 other defendants will face 2,684 plaintiffs.
They allege that Mediator, marketed as an antidiabetic drug, has cost the lives of hundreds of patients.
Mediator was removed from the market in late November 2009. It is believed some five million French patients had used the drug since its introduction in 1976.
Also used as an appetite suppressant, it is suspected of having caused heart and pulmonary failure. Experts believe that between 500 and 2,000 people may have died as a result of taking the drug.
The defendants face seven charges including "unvoluntary homicides and injuries" and "aggravated deceit".
The scale of the case is such that Monday is only expected to be devoted to the organisation of the 110 scheduled hearings. The trial is scheduled to run until April 30, 2020.
A battalion of 376 lawyers will plead during the trial — 353 of whom representing the civil parties — and more than 100 witnesses will be called to testify.
Among the defendants are people who worked for Servier or one of its nine subsidiaries, as well as several members of the ANSM who are implicated for their ties to the pharmaceutical company.
Jacques Servier, who founded the drug-making firm, passed away in 2014 at the age of 92.
Victims' lawyers will argue that Servier knew of the potentially lethal side-effects of the Mediator drug but knowingly concealed them. They will also question whether the French regulator was too slow to act and too close to drug companies.
Servier withdrew the drug from the Spanish and Italian markets in the early 2000s after regulators reported cases of cardiac valvulopathy to the European Medicines Agency.
As of last month, Servier has paid out €131.8 million to thousands of victims.