The diet drug sibutramine (meridia), first approved in 1997 for use in obesity, was voluntarily pulled from the market by Abbott pharmaceuticals on October 8, 2010 based on the results of the SCOUT study. The large SCOUT study involved about 9800 subjects and lasted 3.4 years. All the subjects in the study had a history of cardiovascular disease and/or type 2 diabetes and were at least 55 years old. The study showed that high risk subjects with pre-existing cardiovascular disease had a 16% increase in nonfatal events (stroke or heart attack), but there was no increase in cardiovascular deaths or deaths from any cause. The diabetes-only group (without preexisting cardiovascular disease) did not show an increase in nonfatal events. The average group weight loss was about nine pounds maintained over the course of the study. Sibutramine is not recommended for patients with cardiovascular disease, so this study involved subjects who are not considered candidates for use of the drug.
Lorcaserin, another investigational weight loss drug, was not approved by the FDA. There were tumors in rats which dissuaded the FDA to not approve the drug. In addition, weight loss with this drug was 5% from baseline which, in the FDA’s opinion, was not large enough to justify approval.
Contrave (a sustained-release combination drug of wellbutrin and naltrexone) will be considered for approval by a FDA advisory panel in December. This medication was studied in 1742 patients, and the mean weight loss was 6.1 % in the subjects taking the largest dosage of the drug. Significantly more patients on Contrave lost at least 5% of their body weight than the placebo group. Subjects were more likely to report early reduced hunger or desire for sweet or starchy foods, increased feelings of fullness, reduced incidence and strength of food cravings, reduced eating in response to food cravings, and increased ability to resist food cravings and control of eating. The most frequent adverse event in the Contrave group was nausea. There were significant improvements in waist circumference, insulin resistance, HDL cholesterol, triglycerides and high-sensitivity C-reactive protein.
The Central Ohio Nutrition Center (CONCI) has been involved in research of anti-obesity medications since 1993. CONCI was one of the test sites in the USA for a Contrave trial.