Orexigen Therapeutics, Inc announced that all three remaining phase-3 trials evaluating Contrave (bupropion SR/naltrexone SR), its investigational drug for the treatment of obesity, met their co-primary endpoints. The results from the successfully completed Contrave Obesity Research, or COR, programme of more than 4,500 patients exceed the FDA categorical efficacy benchmark for clinically significant weight loss, supporting the Company's plan to file a New Drug Application (NDA) with the US Food and Drug Administration (FDA) in the first half of 2010.

Across the entire COR programme, seven serious adverse events were attributed by investigators as possibly related to Contrave treatment. These include cholecystitis (gallbladder inflammation), seizure, palpitations, paresthesia and vertigo. The most frequently observed treatment-emergent adverse events were nausea, constipation and headache. Nausea was the leading adverse event resulting in discontinuation; however, for the majority of patients experiencing nausea, it was mild to moderate, transient and manageable.

At week 56, mean blood pressure was generally unchanged from baseline for Contrave patients compared to placebo patients, who tended to experience a slight decrease (approximately 2 mm Hg) from baseline. Contrave treatment did not appear to disrupt the normal circadian pattern of blood pressure. There was a slight increase in pulse (approximately 1 beat per minute) in Contrave patients compared to placebo patients, whose pulse was generally unchanged. There were no meaningful treatment effects on ECGs or laboratory measures including liver function tests. Treatment with Contrave was not associated with increases in symptoms of depression or suicidal ideation.

"The data are remarkably consistent across the COR programme, giving us greater confidence that Contrave has the potential to help obese patients, even those with diabetes, to initiate and sustain weight loss and improve their health," said Dr Ken Fujioka, lead investigator, director of Nutrition and Metabolic Research, Scripps Clinic. "These results mark the beginning of an exciting new era in the treatment of the global obesity epidemic where drug therapies may play an increasingly important role."

Contrave is an investigational medication for the treatment of obesity believed to have a unique mechanism of action that works at two levels within the central nervous system: one associated with controlling the balance of food intake and metabolism and another involved in controlling food preference, reward and cravings.

Orexigen Therapeutics, Inc is a biopharmaceutical company focused on the treatment of obesity.