'Serious Accident' In Medical Drug Trial One person is "brain dead" and four others seriously ill after a "serious accident" during a medical drug trial in France. 18:15, UK,Friday 15 January 2016 The six volunteers are being treated at Rennes University Hospital Five volunteers are seriously ill in hospital after a medical trial at a private clinic in France. One of the five is described as "brain dead" while the other four are critically ill. Some of those who have been taken ill were suffering from a "handicap that could be irreversible," French Health Minister Marisol Touraine said. A sixth person has been taken to hospital, but is not thought to be seriously affected. Health Minister Marisol Touraine has described the incident as 'tragic' Initially it was believed the trial involved a cannabis-based painkiller, but later reports suggested there was no cannabis in the drug. The painkiller compound - manufactured by the Portuguese lab Bial - was being tested by the research company Biotrial, which has offices in London. A total of 90 people were given the drug in various doses, while others were given a placebo, Ms Touraine said. "A serious accident took place during a therapeutic trial near Rennes," the minister said. She added that the trial had been halted and all volunteers taking part recalled. The minister said the six patients had been in good health until taking the oral medication. The study was a Phase I clinical trial, where healthy volunteers take medication to evaluate its safety. "Undertaking Phase 1 studies is highly specialist work," said Daniel Hawcutt, a lecturer in clinical pharmacology at the University of Liverpool. Medicines then go into larger Phase II and Phase III trials to assess their effectiveness and safety before they are finally approved for sale. Ms Touraine expressed her "deep determination to get to the bottom... of this tragic accident". Biotrial said in a statement: "During (...) a study which was being conducted for a sponsor, serious adverse events related to the test drug have occurred in some subjects. "The trial has been conducted in full compliance with the international regulations and Biotrial's procedures were followed at every stage throughout the trial, in particular the emergency procedures for the transfer of subjects to the hospital. "We are in close and regular contact with the Health Authorities and Ministry in France. "The priority at Biotrial remains the safety of our subjects. We are very grateful for the support we have been receiving from our clients and partners today." The first five volunteers to fall ill were taken into hospital earlier this week, French media said. The sixth volunteer, who is not seriously ill, was taken to hospital today as a precaution. A statement issued by the French health ministry confirmed that one of the volunteers is in an "état de mort cérébrale", or "brain dead." Medical lawyer Philippe Courtois told French media: "This is the most serious case I have come across." A formal investigation has been opened in Paris. The emergency comes almost 10 years after six students were left seriously ill after a medical trial in London. In that case, the six volunteers had a severe immune reaction which was triggered by the antibody drug, TGN1412. They survived after intensive care treatment, but were told they faced a lifetime risk of cancer and arthritis. One patient lost fingers and toes to gangrene following the trial at Northwick Park Hospital in London. Another said his head swelled up so he resembled the lead character in the film, The Elephant Man. The six were paid up to £2,000 to take part in that trial.