Biopharmaceutical company Orexigen Therapeutics has begun the fourth round of Phase III clinical trials for its flagship obesity treatment.

The clinical trial consists of a 56-week study that will assess the safety, potential side-effects and efficacy of its obesity drug Contrave in healthy, non-diabetic, obese patients.

Over 1,500 individuals are expected to enrol in the comprehensive testing scheme, which Orexigen hopes will be the last hurdle before the medicine receives approval from the US Food and Drug administration.

Gary Tollefson, chief executive of Orexigen, said that Contrave is a "unique" approach to weight loss that hinges on the scientific community's understanding of cerebral controls over appetite, energy expenditure and the reward-based aspects of eating.

He added: "With this study, Orexigen hopes to provide clinicians and patients with important information on dosing options in the event of a non-response to an initiation dose."

In a previous Phase IIb trial, Contrave delivered statistically-significant weight loss at 24-weeks when compared with placebos as well as individual applications of its constituent drugs bupropion SR and naltrexone IR.

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