A Trial Evaluating the Effectiveness of Contrave in Patients Who Have Weight Recidivism Following Bariatric Surgery

Obesity is associated with increased mortality and morbidity and represents a worldwide epidemic that is increasing in prevalence and remains a significant problem in Canada and a burden on our healthcare system. Maintaining long-term weight loss is the "Achilles' heel" of obesity therapy. Treatment for obesity with surgery is increasing because it has been shown to produce the best results for long-term weight loss and improving obesity related risk factors and diseases. But, these benefits are often reduced by inadequate weight loss or by weight regain in many patients after surgery.

Contrave (naltrexone HCl and bupropion HCl) extended-release tablet is an approved drug and indicated to be used with a low calorie diet and increased physical activity for chronic weight management in obese adults (BMI 30 Kg/m2 or greater) or overweight adults (BMI 27 Kg/m2 or greater) with at least one weight related condition such as hypertension or diabetes. It is unknown how many or which medical treatments for weight loss, such as Contrave work in the subjects who have had bariatric surgery.

This is a 1 year, phase 4, prospective, randomized, double-blind, placebo controlled study that will be conducted across multiple Bariatric Centres of Excellence (BCoE) in Ontario. Consenting participants will be randomly assigned to receive Contrave with usual care (dietary and behaviour counselling) or placebo with usual care. All subjects will also continue to receive usual care. The study includes several follow up visits to assess safety and treatment effects, some in person and others by telephone or video conferencing. Body weight, blood pressure, heart rate, waist circumference, lab tests, and subject completed questionnaires will be collected as part of usual care or for the study. Changes in medications and any possible side effects will also be monitored during the study.

To qualify, men and women must have had prior bariatric surgery (roux en-y gastric bypass or sleeve gastrectomy) at a surgical Center of Excellence within the Ontario Bariatric Network, and have inadequate weight loss or significant weight regain, based on the following OBN criteria:

1. \< 10% total body weight (TBW) loss at 6 months or; 2. \< 20% TBW loss at 12 months or; 3. Weight regain of \> 25% of weight loss.

The aim of this study is to explore the effectiveness of Contrave combined with usual care (dietary and behaviour counselling) compared to placebo with usual care, in patients who have inadequate weight loss or significant weight regain following bariatric surgery.