Current Clinical Trials
Contrave®
Contrave is a fixed dose combination of naltrexone sustained-release (SR) and bupropion SR. We chose these constituents based on the results of our screening model as well as our understanding of the circuitries in the brain that regulate appetite and energy balance. In particular, naltrexone was chosen as a complement to bupropion in order to block compensating mechanisms that attempt to prevent long-term, sustained weight loss.
Naltrexone was approved in the United States in 1984 for the treatment of opioid addiction and in 1995 for the treatment of alcoholism. Naltrexone works by blocking opioid receptors in the brain and inhibits the reinforcing aspects of addictive substances, reducing their perceived reward. It has been shown in numerous studies to negatively alter the palatability, or taste, of many foods, particularly sweets.
Bupropion was approved for marketing in the United States in 1985 for depression and in 1997 for smoking cessation. Functionally, bupropion is thought to increase the level of dopamine activity at specific receptors in the brain, which appears to lead to a reduction in appetite and increase in energy expenditure. It is currently among the most commonly prescribed anti-depressants in the United States. Bupropion has become popular in the treatment of depression not only for its clinical efficacy, but also its attractive side effect profile, including modest weight loss.
NB-301 In October 2007, Orexigen initiated enrollment in its third Phase III clinical trial, a 58-week study designed to assess the safety and efficacy of Contrave in healthy, nondiabetic, obese patients. The trial is taking place at 34 centers nationwide and has randomized 1,742 patients. In April 2008, Orexigen completed enrollment of this trial.
NB-302 In April 2007, Orexigen initiated enrollment in its first Phase III clinical trial, a 56-week study designed to evaluate the safety and efficacy of Contrave alone or when combined with intense diet, exercise and behavior modification. This trial is taking place at nine centers nationwide and has enrolled approximately 800 patients. In November 2007, Orexigen completed enrollment of this trial.
NB-303 In December 2007, Orexigen initiated enrollment in its fourth Phase III clinical trial, a 56-week study designed to assess the safety and efficacy of Contrave in healthy, nondiabetic, obese patients. The trial is taking place at 36 centers nationwide and has randomized approximately 1,495 patients. In May 2008, Orexigen completed enrollment of this trial.
NB-304 In May 2007, Orexigen initiated enrollment in its second Phase III clinical trial, a 56-week study designed to assess the safety and efficacy of Contrave in obese subjects who also have been diagnosed with Type II diabetes. The trial is taking place at 51 centers nationwide and has randomized approximately 500 patients. In May 2008, Orexigen completed enrollment of this trial.