Thus far, “the benefits of medications to treat obesity remain limited because of side effects and inadequate efficacy, especially in the long term.” This is part of an editorial (Siraj ES, Williams J. NEJM 2015; 373: 82-3) that explains a recent study (Pi-Sunyer X, et al. NEJM 2015; 373: 11-22). However, there is a huge need for a cost-effective medication because bariatric surgery is not feasible for 400 million obese persons worldwide.
Liraglutide (marketed as Victoza) has been approved by the FDA for weight loss in adults based on this published study and two other trials. Liraglutide is a glucagon-like peptide-1 (GLP-1) mimetic. The authors conducted a 56-week, double-blind trial with 3731 non-diabetic patients. In a 2:1 design, most patients received a once-daily subcutaneous 3.0 mg injection of liraglutide; some received placebo. Both groups received lifestyle counseling.
- At week 56, the treatment group had lost a mean of 8.4 kg compared with the placebo group which lost 2.8 kg.
There were similar rates of adverse events (mildly increased in treatment group); the rate of new diagnoses of diabetes was less than one-eighth that in the placebo group. A 2-year extension trial is being analyzed to further pursue this finding. Also, the authors note that 4 cases of breast cancer (0.2%) were detected in the treatment group compared with 1 (0.1%) in the placebo group. This finding could have been due to easier exam following weight loss. It is noted that the labeling for liraglutide has a black box warning regarding thyroid c-cell tumor risk which have occurred in rodents at clinically relevant doses.
A fairly good 2 minute summary: NEJM Short Take on Liraglutide
Despite the weight loss, the editorial has a cautious tone.
- “There were statistically significant, although sometimes quantitatively modest, improvements in secondary end points, which included glycemic control, fasting insulin concentrations, cardiometabolic markers, and quality-of-life measures.”
- “Most obese participants stayed obese, reversal of the metabolic syndrome was not quantified, and liraglutide may be required indefinitely, like statins, but with delivery by injection and at a nontrivial cost.” According to http://www.goodrx.com, the approximate retail price is $596.01 for 18 mg. For type 2 diabetes, the dosage varies from 1.2 to 1.8 mg per day, after the first week which is dosed at 0.6 mg.
Take-home point: This new medication may help with modest weight loss but at a very significant cost. In addition, long-term data are lacking. Thus, right now, this medication does not provide the cost-effective option to bariatric surgery.
Related blog posts: