Saxenda launches as the first GLP-1 approved in the US for weight management

Saxenda, a 3 mg once-daily injection of liraglutide, is listed in federal drug data with a marketing start date of December 31, 2014, under new drug application NDA 206321 ^[1]. It is the first GLP-1 receptor agonist available in the United States for chronic weight management rather than for type 2 diabetes alone.

The same molecule has been sold in the US since January 25, 2010 as Victoza under a separate application, NDA 022341, which is approved for type 2 diabetes at doses up to 1.8 mg once daily ^[1][2]. Both products are subcutaneous injections containing liraglutide at 6 mg/mL and are classified as GLP-1 receptor agonists ^[1]. The difference is the approved use and the higher daily dose used for weight management.

What the trial showed

The key evidence comes from the SCALE Obesity and Prediabetes trial, a 56-week double-blind study of 3,731 adults who did not have type 2 diabetes and who had a body-mass index of at least 30, or at least 27 with treated or untreated high cholesterol or high blood pressure ^[2]. Participants were randomly assigned 2:1 to liraglutide 3.0 mg (2,487 people) or placebo (1,244 people), and both groups received counseling on diet and exercise ^[2]. The dose started at 0.6 mg and rose by 0.6 mg each week to 3.0 mg ^[2].

At the start, the average age was 45.1 years, average weight was 106.2 kg (about 234 pounds), average BMI was 38.3, 78.5% of participants were women, and 61.2% had prediabetes ^[2].

At week 56, the liraglutide group had lost an average of 8.4 kg (about 18.5 pounds) compared with 2.8 kg (about 6 pounds) in the placebo group, a difference of 5.6 kg, or roughly 12 pounds (95% confidence interval −6.0 to −5.1; P<0.001) ^[2]. A total of 63.2% of people taking liraglutide lost at least 5% of their starting weight, versus 27.1% on placebo, and 33.1% lost more than 10%, versus 10.6% on placebo ^[2].

The most commonly reported side effects with liraglutide were mild or moderate nausea and diarrhea ^[2]. Serious adverse events occurred in 6.2% of the liraglutide group and 5.0% of the placebo group ^[2]. Fewer than three-quarters of participants finished the study: 71.9% of the liraglutide group and 64.4% of the placebo group completed 56 weeks of treatment ^[2].

The trial ran from June 1, 2011 through March 18, 2013 at 191 sites in 27 countries and was funded by Novo Nordisk, which also planned and performed the statistical analyses and supplied the study drugs ^[2].

Why it matters for patients

Until now, GLP-1 medicines in the US were prescribed for blood sugar control in type 2 diabetes. A dedicated weight-management approval means a GLP-1 can be prescribed specifically for obesity or for overweight with a weight-related health problem, using the BMI thresholds studied in the trial: 30 and above, or 27 and above with conditions such as high cholesterol or high blood pressure ^[2].

The trial numbers also set expectations. Average loss was about 8 kg over 56 weeks, with roughly one in three people losing more than 10% of their starting weight, and about one in four on liraglutide did not complete the study ^[2]. Nausea and diarrhea were the most common complaints ^[2].

The study excluded people with type 1 or type 2 diabetes, a history of pancreatitis, prior bariatric surgery, severe psychiatric disorders, and a personal or family history of medullary thyroid cancer or multiple endocrine neoplasia type 2 ^[2]. That means the results describe a specific population, not everyone who might seek treatment.

US pricing, insurance coverage and pharmacy availability are not described in these sources, so those details are not yet known from the material here.

What happens next

A two-year extension of the trial in participants with prediabetes, designed to test whether liraglutide delays the onset of type 2 diabetes, was recently completed; its results are not reported in the 56-week publication ^[2].