France's health ministry has presented a plan to tighten rules governing human drug trials after a trial in Rennes in January of this year led to the death of one volunteer and left five others (all male) in serious or critical condition. The incident, called the worst of its kind ever in France, occurred during Phase I tolerability tests with a drug manufactured by Portugal’s Bial. It led to the suspension until further notice of all further tests with the medication, which was designed to treat Alzheimer’s and Parkinson’s diseases.

Studies with the medication compound that acts on the body's endocannibanoid system, a group of receptor proteins that responds to compounds naturally made in the body as well as being components in cannabis, were being carried out by a private company, Biotrial, based at Rennes.

Health Minister, Marisol Touraine, has ordered Biotrial to provide an action plan within a month to avoid such negative outcomes or have its permission to conduct trials rescinded.

Touraine said the investigation by the French health administration showed that the trial was compliant with the current legislation, but there were breaches in the way Biotral handled the problem.

The incident should have been reported without delay to the National Agency for Drug Safety, the minister said. However, the lab only made its first formal report on Jan. 14, four days after the first volunteer was taken to a hospital and three days after the decision was made to suspend the test.

In total, 108 volunteers reportedly took part in the trial, with 90 receiving the drug at varying doses and the remainder given placebos. The six men who had severe reactions are believed to have been among those given the highest dose.

The French incident was the second of similar dimension in a clinical trial since 2006, when six volunteers taking a German-manufactured autoimmune drug in a London probe were left seriously impaired.