A study showing that once-weekly subcutaneous semaglutide 2.4 mg (Wegovy, Novo Nordisk) produces greater long-term weight loss than once-daily injected liraglutide 3.0 mg (Saxenda, Novo Nordisk) among adults with overweight or obesity without diabetes has now been published.
The findings are from the phase 3 Semaglutide Treatment Effect in People with Obesity (STEP) 8 trial by Domenica M. Rubino, MD, of the Washington Center for Weight Management and Research, Arlington, Virginia, and colleagues.
Semaglutide and liraglutide, subcutaneously injectable glucagon-like peptide-1 (GLP-1) agonists, were both first approved for the treatment of type 2 diabetes in the United States and elsewhere, but are now also approved, in different doses, for chronic weight management and in people with obesity or overweight and comorbidities. A phase 2 trial demonstrated that once-daily semaglutide 0.4 mg produced significantly more weight loss than liraglutide 3.0 mg.
“Semaglutide and liraglutide induce weight loss by lowering energy intake. However, the reduction in caloric intake versus placebo appears to be larger with semaglutide (35%) than liraglutide (approximately 16%),” say Rubino and colleagues.
“Semaglutide has also been associated with reductions in food cravings, which is less evident with liraglutide, suggesting different mechanisms of energy intake regulation,” they add.
Novo Nordisk has recently reported that there may be supply problems with Wegovy, as a contract manufacturer that fills syringes for pens to inject the drug temporarily halted deliveries and manufacturing after issues related to good manufacturing practice.
The company is also developing an oral form of semaglutide for weight loss. The oral form has already been approved in doses of 7 or 14 mg/day for the treatment of type 2 diabetes in the United States as Rybelsus.
Individualize Treatment for Those With Obesity
STEP 8 was a randomized, open-label, 68-week phase 3b trial of 338 adults randomized to once-weekly semaglutide 2.4 mg (n = 126), once-daily liraglutide 3.0 mg (n=127), or matched injected placebo (n = 85) for 68 weeks, all provided with counseling on diet and physical activity.
The primary outcome — estimated mean change in body weight at week 68 — was –15.8% with semaglutide versus –6.4% with liraglutide, a significant difference (P < .001). The proportions of patients achieving loss of body weight of 10%, 15%, or 20% were 70.9%, 55.6%, and 38.5% with semaglutide versus 25.6%, 12.0%, and 6.0% with liraglutide, respectively.
Significantly greater reductions were also seen at 68 weeks for weekly semaglutide versus daily liraglutide in absolute body weight, waist circumference, diastolic blood pressure, total cholesterol, very low-density cholesterol, triglycerides, A1c, fasting plasma glucose, and C-reactive protein. Differences in systolic blood pressure, LDL and HDL cholesterol, free fatty acids, and fasting serum insulin did not achieve significance.
Overall, 19.8% of patients permanently discontinued treatment, with the most discontinuations in the liraglutide group (27.6%), followed by placebo (17.6%) and semaglutide (3.5%). Time to first and permanent discontinuation were shorter with liraglutide than with semaglutide or placebo.
Adverse events were reported by 95.2% of patients with semaglutide, 96.1% with liraglutide, and 95.3% with placebo. Gastrointestinal disorders were the most common with the two active drugs, reported by 84.1% with semaglutide and 82.7% with liraglutide versus 55.3% with placebo.
Most side effects were mild to moderate and resolved without treatment discontinuation. Severe gastrointestinal adverse events were reported by only 3.2%, 2.4%, and 3.5% of patients with semaglutide, liraglutide, and placebo, respectively.
“This trial found weight loss with semaglutide was significantly greater than with liraglutide. However, the variability in treatment response means an individual’s tolerance and sensitivity to a specific treatment is important for obesity management,” the researchers observe.
“Therefore, having multiple antiobesity medications proven to lower body weight through different mechanisms, with different adverse effect profiles and dosing regimens, can only benefit clinicians and patients,” they conclude.
The trial was funded by Novo Nordisk. Rubino has reported being a clinical investigator for Boehringer Ingelheim, AstraZeneca, and Novo Nordisk; receiving honoraria from WebMD; receiving speaker fees, consulting fees, scientific advisory fees, and honoraria from Novo Nordisk; receiving grants from SARL and personal fees from Medscape, PeerView, and the Endocrine Society; and being a shareholder in Novo Nordisk.
JAMA. Published online January 11, 2022. Abstract
Miriam E. Tucker is a freelance journalist based in the Washington, DC, area. She is a regular contributor to Medscape, with other work appearing in The Washington Post, NPR’s Shots blog, and Diabetes Forecast magazine. She is on Twitter: @MiriamETucker.