The phase 3b IGNITE study shows that naltrexone/bupropion (Contrave/Mysimba, Orexigen) combined with a comprehensive lifestyle intervention led to greater weight loss at 26 weeks than usual care consisting of a doctor’s advice to lose weight and be more active.
Specifically, obese and overweight patients who responded to naltrexone/bupropion plus a comprehensive lifestyle intervention lost 9.5% of their body weight, whereas patients in the usual-care group lost just 0.9% of their body weight at 26 weeks (P < .001), the primary study end point.
Moreover, “the efficacy was maintained for at least 78 weeks, a longer duration than has been previously studied,” Amy Halseth, PhD, with Orexigen Therapeutics, La Jolla, California, and colleagues report in an article published online in Obesity.
The results provide hope for meaningful weight loss, Scott Kahan, MD, MPH, director of the National Center for Weight and Wellness, George Washington University, Washington, DC, and chair of the clinical committee of the Obesity Society, who was not involved in the study, told Medscape Medical News.
“There’s an overriding sense of futility among physicians and patients that nothing works for weight management, especially longer-term weight management, and this is a great example refuting that,” he said.
Patients in the usual-care group received “what usually happens: the doctor basically tells the patient ‘you should lose weight’ without providing comprehensive counseling, referrals, or medications.”
In contrast, the other study arm showed that “with just a little bit of decent counseling and when appropriate, a medication, we can go a long way; a lot of people lost > 15% of their body weight, which is what you get with lap-band surgery, and [among responders] virtually everyone (80% or more) had a meaningful > 5% weight loss,” Dr Kahan added.
“I think this study should incite optimism among clinicians that there’s a lot we can be doing if we spend some time with our patients focusing on this,” he continued.
As previously reported, another study, the LIGHT trial — to test cardiovascular-disease rates with naltrexone/bupropion — was controversially stopped in May 2015 due to leaked results from 25% of planned enrollment, and the phase 4 CONVENE trial, set to replace the LIGHT study, was also ended, in April 2016, after Takeda sold its US rights to Contrave to Orexigen.
Dr Kahan said it would be good to see a completed cardiovascular-outcomes trial, but as bupropion and naltrexone “have been around for 60, 70 years…I’m not bothered at all” that these trials were not completed, he commented.
Since Contrave includes the antidepressant bupropion, as with all antidepressants, there is a warning that it may cause suicidal thoughts in people under age 24.