Background: STEP TEENS (NCT04102189) was the first phase 3a trial to examine efficacy and safety of once-weekly subcutaneous semaglutide 2.4 mg (sema) + lifestyle intervention in adolescents (12–<18 yrs) with obesity (BMI ≥95th percentile), or overweight (BMI ≥85th percentile) with ≥1 weight-related comorbidity.
Methods: Participants were randomised 2:1 to sema (n=134) or matching placebo (PBO; n=67). Endpoints (baseline [BL]–wk 68) were %-change in BMI (primary), ≥5% weight loss (WL; confirmatory secondary), ≥10, ≥15 and ≥20% WL, change in cardiometabolic risk factors and quality of life (QoL; secondary), assessed by the treatment policy estimand. Primary and confirmatory secondary endpoints were controlled for multiplicity.
Results: Of 201 adolescents (62.2% female; mean age 15.4 yrs, body weight 107.5 kg, BMI 37.0 kg/m2) randomised, 89.6% completed treatment. Mean change in BMI (BL–wk 68) was −16.1% (sema) vs 0.6% (PBO; estimated treatment difference [ETD]: −16.7%-points; 95% CI: −20.3;−13.2; p<0.0001). ETD in body weight %-change (BL–wk 68) for sema vs PBO was −17.4%-points (95% CI: −21.1;−13.7; p<0.0001). More participants achieved ≥5, ≥10, ≥15 and ≥20% WL with sema vs PBO (72.5 vs 17.7%, 61.8 vs 8.1%, 53.4 vs 4.8%, 37.4 vs 3.2%; p<0.0001). Waist circumference, HbA1c and lipids (except HDL) were reduced with sema (p<0.05). Sema improved overall weight-related QoL (p=0.038) and physical comfort (p=0.005). Adverse events (AEs) were reported by 78.9% (sema) and 82.1% (PBO) of participants. Serious AEs were reported by 11.3% (sema) and 9.0% (PBO) of participants. More participants reported gastrointestinal AEs with sema (61.7%) vs PBO (41.8%). In each group, 4.5% of participants stopped treatment due to AEs.
Conclusions: In adolescents with overweight/obesity, sema resulted in significant reductions in BMI, body weight and waist circumference, and improvements in cardiometabolic risk factors and QoL. Sema was generally well tolerated, with a safety profile consistent with the GLP-1RA class.