Real-World Evidence Study of Naltrexone/Bupropion for Achieving Clinically Significant Weight Loss

Background: Naltrexone/Bupropion (NB) was approved as an anti-obesity medication (AOM) based on the Contrave Obesity Research (COR) trials, which assessed weight loss at weeks 28 and 56. Prior research suggests that weight loss within three months of AOM treatment predicts long-term success. This study evaluates the real-world effectiveness of NB in achieving clinically significant weight loss after three months of adherence and compares long-term outcomes to the COR trials. Methods: A retrospective chart review was conducted at a Canadian community clinic. Patients were included if they had obesity (class I–III), adhered to NB for at least three months, were treated solely with NB (June 2019–March 2023), and were ≥18 years old. Weight loss was calculated from baseline at three months, and for those with longer adherence (26, 52, and 104 weeks). Results: Among 125 patients completing three months of NB, the mean weight loss was 4.9% (clinically significant). Of those continuing NB, 57.6% had already lost ≥5% by three months. At six months (n=72), weight loss was 8.6%. At 52 weeks (n=33), it was 11.3%, and at 104 weeks (n=11), it reached 11.8%. Conclusion: NB effectively achieves clinically significant weight loss within three months. Longer-term real-world outcomes align with COR trial findings, supporting NB’s sustained effectiveness in obesity treatment.