Background: Obesity is a global health challenge with few pharmacologic options. Whether adults with obesity can achieve weight loss with once-weekly semaglutide at a dose of 2.4 mg as an adjunct to lifestyle intervention has not been confirmed.

Methods: In this double-blind trial, we enrolled 1961 adults with a body-mass index (the weight in kilograms divided by the square of the height in meters) of 30 or greater (≥27 in persons with ≥1 weight-related coexisting condition), who did not have diabetes, and randomly assigned them, in a 2:1 ratio, to 68 weeks of treatment with once-weekly subcutaneous semaglutide (at a dose of 2.4 mg) or placebo, plus lifestyle intervention. The coprimary end points were the percentage change in body weight and weight reduction of at least 5%. The primary estimand (a precise description of the treatment effect reflecting the objective of the clinical trial) assessed effects regardless of treatment discontinuation or rescue interventions.

Results: The mean change in body weight from baseline to week 68 was -14.9% in the semaglutide group as compared with -2.4% with placebo, for an estimated treatment difference of -12.4 percentage points (95% confidence interval [CI], -13.4 to -11.5; P<0.001). More participants in the semaglutide group than in the placebo group achieved weight reductions of 5% or more (1047 participants [86.4%] vs. 182 [31.5%]), 10% or more (838 [69.1%] vs. 69 [12.0%]), and 15% or more (612 [50.5%] vs. 28 [4.9%]) at week 68 (P<0.001 for all three comparisons of odds). The change in body weight from baseline to week 68 was -15.3 kg in the semaglutide group as compared with -2.6 kg in the placebo group (estimated treatment difference, -12.7 kg; 95% CI, -13.7 to -11.7). Participants who received semaglutide had a greater improvement with respect to cardiometabolic risk factors and a greater increase in participant-reported physical functioning from baseline than those who received placebo. Nausea and diarrhea were the most common adverse events with semaglutide; they were typically transient and mild-to-moderate in severity and subsided with time. More participants in the semaglutide group than in the placebo group discontinued treatment owing to gastrointestinal events (59 [4.5%] vs. 5 [0.8%]).

Conclusions: In participants with overweight or obesity, 2.4 mg of semaglutide once weekly plus lifestyle intervention was associated with sustained, clinically relevant reduction in body weight. (Funded by Novo Nordisk; STEP 1 ClinicalTrials.gov number, NCT03548935).

The STEP 5 trial assessed the efficacy and safety of once-weekly subcutaneous semaglutide 2.4 mg versus placebo (both plus behavioral intervention) for long-term treatment of adults with obesity, or overweight with at least one weight-related comorbidity, without diabetes. The co-primary endpoints were the percentage change in body weight and achievement of weight loss of ≥5% at week 104. Efficacy was assessed among all randomized participants regardless of treatment discontinuation or rescue intervention. From 5 October 2018 to 1 February 2019, 304 participants were randomly assigned to semaglutide 2.4 mg (n = 152) or placebo (n = 152), 92.8% of whom completed the trial (attended the end-of-trial safety visit). Most participants were female (236 (77.6%)) and white (283 (93.1%)), with a mean (s.d.) age of 47.3 (11.0) years, body mass index of 38.5 (6.9) kg m-2 and weight of 106.0 (22.0) kg. The mean change in body weight from baseline to week 104 was -15.2% in the semaglutide group (n = 152) versus -2.6% with placebo (n = 152), for an estimated treatment difference of -12.6 %-points (95% confidence interval, -15.3 to -9.8; P < 0.0001). More participants in the semaglutide group than in the placebo group achieved weight loss ≥5% from baseline at week 104 (77.1% versus 34.4%; P < 0.0001). Gastrointestinal adverse events, mostly mild-to-moderate, were reported more often with semaglutide than with placebo (82.2% versus 53.9%). In summary, in adults with overweight (with at least one weight-related comorbidity) or obesity, semaglutide treatment led to substantial, sustained weight loss over 104 weeks versus placebo. NCT03693430.

Background: Semaglutide is an effective treatment for type 2 diabetes; however, 20-30% of patients given semaglutide 1·0 mg do not reach glycaemic treatment goals. We aimed to investigate the efficacy and safety of once-weekly semaglutide 2·0 mg versus 1·0 mg in adults with inadequately controlled type 2 diabetes on a stable dose of metformin with or without a sulfonylurea.

Methods: We did a 40-week, randomised, active-controlled, parallel-group, double-blind, phase 3B trial (SUSTAIN FORTE) at 125 outpatient clinics in ten countries. Participants (≥18 years) with inadequately controlled type 2 diabetes (HbA1c 8·0-10·0%) with metformin and with or without sulfonylurea were randomly assigned (1:1) by an interactive web-response system to 2·0 mg or 1·0 mg once-weekly semaglutide. Participants, site personnel, the clinical study group, and investigators were masked to the randomised treatment. Outcomes included change from baseline at week 40 in HbA1c (primary outcome) and bodyweight (secondary confirmatory outcome), evaluated through trial product estimand (no treatment discontinuation or without rescue medication) and treatment policy estimand (regardless of treatment discontinuation or rescue medication) strategies. This study is registered with ClinicalTrials.gov, NCT03989232; EudraCT, 2018-004529-96; and WHO, U1111-1224-5162.

Findings: Between June 19 and Nov 28, 2019, of 1515 adults assessed for eligibility, 961 participants (mean age 58·0 years [SD 10·0]; 398 [41%] women) were included. Participants were randomly assigned to once-weekly semaglutide 2·0 mg (n=480 [50%]) or 1·0 mg (n=481 [50%]); 462 (96%) patients in the semaglutide 2·0 mg group and 471 (98%) in the semaglutide 1·0 mg group completed the trial. Mean baseline HbA1c was 8·9% (SD 0·6; 73·3 mmol/mol [SD 6·9]) and BMI was 34·6 kg/m2 (SD 7·0). Mean change in HbA1c from baseline at week 40 was -2·2 percentage points with semaglutide 2·0 mg and -1·9 percentage points with semaglutide 1·0 mg (estimated treatment difference [ETD] -0·23 percentage points [95% CI -0·36 to -0·11]; p=0·0003; trial product estimand) and -2·1 percentage points with semaglutide 2·0 mg and -1·9 percentage points with semaglutide 1·0 mg (ETD -0·18 percentage points [-0·31 to -0·04]; p=0·0098; treatment policy estimand). Mean change in bodyweight from baseline at week 40 was -6·9 kg with semaglutide 2·0 mg and -6·0 kg with semaglutide 1·0 mg (ETD -0·93 kg [95% CI -1·68 to -0·18]; p=0·015; trial product estimand) and -6·4 kg with semaglutide 2·0 mg and -5·6 kg with semaglutide 1·0 mg (ETD -0·77 kg [-1·55 to 0·01]; p=0·054; treatment policy estimand). Gastrointestinal disorders were the most commonly reported adverse events (163 [34%] in the 2·0 mg group and 148 [31%] in the 1·0 mg group). Serious adverse events were similar between treatment groups, reported for 21 (4%) participants given semaglutide 2·0 mg and 25 (5%) participants given semaglutide 1·0 mg. Three deaths were reported during the trial (one in the semaglutide 1·0 mg group and two in the semaglutide 2·0 mg group).

Interpretation: Semaglutide 2·0 mg was superior to 1·0 mg in reducing HbA1c, with additional bodyweight loss and a similar safety profile. This higher dose provides a treatment intensification option for patients with type 2 diabetes treated with semaglutide in need of additional glycaemic control.