Paris - One man is brain dead and three others are facing possible permanent brain damage after volunteering to take part in a botched drug test in western France, French authorities said Friday.
The Paris prosecutor's office has opened an investigation into what French Health Minister Marisol Touraine called “an accident of exceptional gravity” at the private Biotrial clinical lab in the city of Rennes.
The drug trial, which was testing a new painkiller compound, involved 90 healthy volunteers who were given the experimental drug in varying doses at different times, she told reporters Friday at a news conference in Rennes.
Six male volunteers between 28 and 49 years old have since been hospitalized, including one man now classified as brain dead, Touraine said, adding that all the other 83 volunteers are being contacted.
The drug trial for the six hospitalized men began on January 7 and was halted Monday.
The chief neuroscientist at the hospital in Rennes, Professor Gilles Edan, said in addition to the brain-dead man, three other male medical volunteers could have “irreversible” brain damage. A fifth man is suffering from neurological problems and a sixth man is being kept in the hospital but is in a less critical condition, he said.
Edan said there's no known way to reverse the effects of the experimental drug that Biotrial was testing. The drug is based on a natural brain compound similar to the active ingredient in marijuana.
Touraine said the experimental drug was not based on cannabis, as some media reports had claimed. She urged calm, saying that no drug currently on the market was implicated in the failed trial.
The drug was produced by the Portuguese pharmaceutical company Bial, which said Friday that 108 healthy people had already taken part in the trials and had no moderate or serious reactions to the drug, a new molecule to treat pain. Bial added that initial testing for the drug started in June 2015 following toxicology tests.
It's rare for volunteers to fall seriously ill when testing new drugs. Researchers generally start with the lowest possible dose for humans after extensive drug tests in animals. The French ministry statement said those who had fallen ill had taken an oral medication in the first phase of testing, which was studying safe usage, tolerance and other measures on healthy volunteers.
Biotrial, which has headquarters in Rennes and offices in London and Newark, New Jersey, says it has over 25 years of experience in clinical trials and uses “state-of-the-art facilities.” In France, adults volunteering for Biotrial tests can earn between 100 euros and 4,500 euros ($110 to $4,920).
In 2006, Britain saw a similar incident, when six previously healthy men were treated for organ failure only hours after being given an experimental drug targeting the immune system. That prompted a review of procedures and resulted in the U.K. regulatory agency imposing new testing standards, including recommendations to use the lowest possible dose and to test new drugs only in one person at a time.
The six men in Britain now apparently have a higher risk of cancer and autoimmune diseases tied to their exposure to the experimental drug.
Dr. Ben Whalley, a neuropharmacology professor at Britain's University of Reading, said standardized regulations for clinical trials are “largely the same” across Europe.
“However, like any safeguard, these minimize risk rather than abolish it,” Whalley said in a statement. “There is an inherent risk in exposing people to any new compound.”