A phase 3a trial showed a once-weekly 2.4mg dose of semaglutide in combination with intensive behavioral therapy (IBT) helped patients lose significantly more weight than placebo and IBT. 

According to a press release from the manufacturer, the phase 3a STEP 3 trial looked at the treatment’s safety and efficacy after 68 weeks. In the trial, IBT included 30 counseling sessions with a dietician, a reduced-calorie diet, and increased physical activity. Patients enrolled in the trial were adults deemed obese with a BMI ≥ 30 kg/m² or overweight with a BMI ≥ 27 kg/m² with at least one weight-related comorbidity and without type 2 diabetes. 

The release noted that patients treated with semaglutide lost an average of 16.0% of their body weight from baseline, compared to 5.7% for the placebo group (estimated treatment difference: -10.3 [95% CI: -12.0, -8.6] p<0.0001). In addition, 87% of patients in the treatment arm lost greater than or equal to 5% of their body weight, compared to 48% in the placebo group. 

“Given the multiple weight-loss related challenges faced by people with obesity, patients and practitioners alike need additional medical therapies to support lifestyle interventions, such as IBT, which is a highly intensive weight loss approach,” said Tom Wadden, PhD, lead investigator from the Perelman School of Medicine at the University of Pennsylvania. “I’m encouraged to see the significant additional weight loss and improvements in certain cardiometabolic disease risk factors achieved with semaglutide 2.4 mg when added to IBT.” 

The release noted that semaglutide also provided more significant benefits in cardiometabolic risk factors, including waist circumference (-14.6 vs. -6.3 cm) and systolic blood pressure (-5.6 vs. -1.6 mmHg), compared to placebo. 

The number of patients reporting adverse events was similar in the two groups, with the most common adverse events in the semaglutide group being nausea, vomiting, diarrhea, and constipation. These symptoms were reported in 82.8% of patients in the semaglutide group, compared to 63.2% in the placebo group. According to the release, the higher rate in the drug group “was driven by more gallbladder-related serious events and single events unrelated to the treatment.” 

Results of the trial were presented at the Obesity Week 2020 interactive congress.