A patient who was left braindead following a Phase I clinical trial at the University Hospital of Rennes in France has died.

As part of the trial begun in June last year, the drug developed by Portuguese pharmaceutical company Bial was administered to 108 patients.

The Guardian reported that 90 patients were given the drug at varying doses, while the rest of them were given placebos.

The fatty acid amide hydrolase (FAAH) enzyme inhibitor left another five people in hospital who showed severe symptoms.

However, the Rennes hospital said that the patients were in a stable condition.

Those hospitalised include men aged between 28 and 49 who have repeatedly taken the medication, which is aimed at treating pain and mood disorders such as anxiety, the Business Standard reported.

The trial was approved by the French Regulatory Authorities, as well as by the French Ethics Committee, in accordance with the guidelines of Good Clinical Practices. The approval followed the completion of tests and pre-clinical trials, particularly in the area of toxicology.

Bial said in a statement that it will keep following the hospitalised volunteers and work closely with the health authorities to understand the causes of this tragic and unfortunate situation.

Founded in 1924, Bial develops, produces and markets new drugs including anti-inflammatories, antidiabetics, cardiovascular, anti-asthmatics, antibiotics, antidepressants and antianemics.