Paris, January 16 (RHC)-- Six men have been hospitalized — and one of them was pronounced brain-dead — after a drug trial in northwestern France, the country’s health minister said on Friday.

Marisol Touraine, the minister for social affairs, health and women’s rights, said in a statement that her office was informed about a “serious accident” that resulted in the hospitalization of the six men, at the Centre Hospitalier Universitaire de Rennes, in eastern Brittany.

The French health minister said that the patients, all men, were ages 28 to 49. The head of the hospital’s neurology department told reporters that three men may have suffered irreversible brain damage, based on magnetic resonance imaging scans, but cautioned that the scans were not conclusive.

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. Of 128 participants, 90 were given the drug, and the rest a placebo.