LONDON — Six men were hospitalized — and one of them was pronounced brain-dead — after a drug trial in northwestern France, the country's health minister said Friday.
Marisol Touraine, the minister for social affairs, health and women's rights, said in a statement that her office was informed Thursday evening about a "serious accident" that resulted in the hospitalization of the six men, at the Centre Hospitalier Universitaire de Rennes, in eastern Brittany.
Calling the incident "unprecedented" at an afternoon news conference in Rennes, Touraine said: "I have no knowledge of a comparable event."
The patients, all men, ranged in age from 28 to 49, she said. The head of the hospital's neurology department said that three men may have suffered irreversible brain damage, based on magnetic resonance imaging scans, but cautioned that the scans were not conclusive.
"I was deeply moved by their suffering," Touraine said after visiting the patients and their families.
The drug was administered orally to healthy volunteers as part of a Phase 1 clinical trial by Biotrial, a drug-evaluation company based in Rennes, on behalf of a Portuguese drug manufacturer, Bial. The drug is intended to help with mood, anxiety and motor problems linked to neurodegenerative diseases by having an effect on the endocannabinoid system, a set of brain receptors. Of 128 participants, 90 were given the drug, and the rest a placebo.
In a statement, Biotrial acknowledged "serious adverse effects" in a trial, adding: "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."
A spokesman for Bial, based in Coronado, Portugal, said the company had no immediate comment.
Biotrial submitted its application to conduct the trial, on April 30, Touraine said. The French Agency for the Safety of Health Products, the country's drug regulator, authorized the trial on June 26, and it began July 9.
Touraine said the drug had previously been tested on animals, including chimpanzees, and had been administered to 90 people under the trial. The six men received the drug several times, starting Jan. 7. The first symptoms appeared in one man on Sunday; he was quickly hospitalized, and the others followed. The trial was halted the next day.
Contrary to several reports in the French news media, the drug was not a cannabis-based painkiller, Touraine said.
Along with the French drug regulation agency, the country's General Inspectorate of Social Affairs, the Rennes prosecutor's office and the health branch of the Paris prosecutor's office have opened investigations.
Deaths or serious adverse reactions during Phase 1 clinical trials — which focus primarily on a drug's safety and side effects, rather than on its effectiveness — are rare.
In March 2006, six previously healthy young men fell ill and spent weeks in intensive care, with severe damage to their immune systems, at Northwick Park Hospital in London after being injected with an immune-system stimulant, known as TGN1412, during a Phase 1 trial.
Despite its potency, the drug, which was held up as a potential treatment for multiple sclerosis, leukemia and rheumatoid arthritis, was tested under much the same standards as those governing ordinary pharmaceuticals. British regulators approved the trial in just 17 days, and the testing company, based in Massachusetts, did not have an adequate response plan in the event of a disastrous adverse reaction, British investigators concluded.
"Toxicity deaths in Phase 1 trials are rare," said Daniel P. Carpenter, a professor of government at Harvard and an authority on the U.S. Food and Drug Administration. Some deaths were reported in Phase 1 trials early in the effort to treat AIDS, he said, but "nothing like this in a long time."
A meta-analysis of non-cancer Phase 1 drug trials, published last year in The British Medical Journal, found serious adverse events in only 0.31 percent of participants, and no life-threatening events or deaths.