Following successful results in clinical trials with its potential weight loss drug Contrave, Orexigen Therapeutics has taken the next step for market approval and submitted a New Drug Application (NDA) to the U.S. Food and Drug Administration (FDA).
Contrave is now one of several obesity drugs that are currently awaiting FDA approval. Rather than affecting food digestion and blocking fat absorption, Contrave acts on the central nervous system to reduce hunger, increase energy expenditure, and negatively alter the palpability of sweets.
If approval of the NDA is granted, the company will legally be able to sell and market Contrave in the United States as a weight loss therapy, although consumer use will require a prescription from a medical professional.
The Contrave clinical trials involved more than 4,500 patients and yielded a substantial body of evidence which seems to support the safety and efficacy of the product. The results of the randomized, double-blind, placebo-controlled trials showed that patients given Contrave lost more weight than patients in the placebo group. All patients who participated in the clinical program followed the same diet and exercise program.
The weight loss drug is a combination therapy of two well-established drugs, bupropion and naltrexone. These two active ingredients have been widely used for over 20 years. Bupropion is a popular antidepressant and smoking cessation medication; naltrexone is prescribed for alcohol and opioid addiction treatment.
By combining these two drugs, Contrave is designed to address both the physiological and behavioral aspects of obesity. Obesity is thought to alter the body’s circuitry so that it is resistant to leptin satiety signals and ineffectively regulates reward-based eating behavior.
Highlights of the Contrave clinical trials:
- Contrave exceeded the FDA efficacy benchmark: Percent of patients who lost at least 5% of their body weight in the two phases of trials were 48% and 56% of Contrave patients compared to 16% and 18% of placebo patients
- Few side effects, although some patients experienced nausea, constipation, vomiting, dizziness, and dry mouth
- Patients treated with Contrave reported greater control of eating and showed significant improvement in quality of life
Although Contrave is being touted as a potential pharmacological solution for the treatment of obesity, weight loss will still require a patient to follow a healthy diet and adopt a more active lifestyle.
Other potential weight loss drugs that have been submitted to the FDA for approval are Qnexa (Vivus Inc) and Lorcaserin (Arena Therapeutics Inc).
