Semaglutide 2.4 mg led to 12.1% average weight loss in East Asian population trial

Once-weekly semaglutide 2.4 mg helped adults with overweight or obesity lose an average of 12.1% of their body weight over 44 weeks in a trial conducted mainly in East Asia, results published in The Lancet Diabetes & Endocrinology show. Participants who received a placebo lost an average of 3.6% over the same period, and everyone in the study also received diet and physical activity support ^[1].

The study, called STEP 7, was a phase 3a randomized, double-blind trial run at 23 hospitals and trial centers in China, Hong Kong, Brazil and South Korea. Researchers screened 448 people between Dec. 8, 2020, and Aug. 23, 2022, then randomly assigned 375 of them in a 2-to-1 ratio: 249 to semaglutide 2.4 mg and 126 to placebo. Both groups gave themselves a subcutaneous injection once a week for 44 weeks, alongside a diet and physical activity program. Randomization was stratified by whether a participant had type 2 diabetes, so the trial enrolled people with and without the condition ^[1]. Semaglutide is a GLP-1 receptor agonist ^[1].

The main result was measured as percentage change in average body weight. From the start of the trial to week 44, the semaglutide group's average weight fell 12.1% (standard error 0.5), while the placebo group's fell 3.6% (standard error 0.7). The estimated difference between the groups was 8.5 percentage points (95% confidence interval 10.2 to 6.8; p<0.0001) ^[1].

A second measure looked at how many people lost at least 5% of their body weight. That was 203 of 238 people (85%) taking semaglutide and 36 of 116 (31%) taking placebo, an odds ratio of 13.1 (95% confidence interval 7.4 to 23.1; p<0.0001) ^[1].

Side effects were common in both groups. Adverse events were reported by 231 of 249 participants (93%) on semaglutide and 108 of 126 (86%) on placebo. The most common were gastrointestinal disorders, reported by 168 of 249 (67%) on semaglutide and 45 of 126 (36%) on placebo ^[1]. The published abstract gives that broad category rather than individual symptoms or their severity.

The authors concluded that the results support the use of semaglutide 2.4 mg for weight management in people of East Asian ethnicity with overweight or obesity, with or without type 2 diabetes ^[1]. The trial was funded by Novo Nordisk ^[1]. The journal also published a commentary titled "GLP-1 analogue therapy for obesity in people from Asia" ^[1].

Why it matters for patients

The trial was designed because data on semaglutide's weight-management benefits in people from East Asia were insufficient, the authors wrote ^[1]. For patients, 12.1% is a group average across 249 people, not a prediction for any one person. The publication does not report how many participants lost no weight, and the abstract does not break the results down by whether someone had type 2 diabetes ^[1].

Everyone in both groups received diet and physical activity support, and the placebo group still lost an average of 3.6% of body weight over 44 weeks ^[1]. That gives a sense of how much of the change came from the program and the trial setting rather than the drug.

Gastrointestinal disorders were the most frequently reported side effect and appeared about twice as often with semaglutide (67%) as with placebo (36%) ^[1]. The abstract reports only that category, so which specific symptoms occurred, and how long they lasted, has not been disclosed.

The results cover 44 weeks of treatment. What happened to participants' weight after the injections stopped has not been reported in this publication ^[1].

What happens next

The trial is complete and is registered with ClinicalTrials.gov as NCT04251156 ^[1]. Longer-term results, including whether weight was regained after treatment ended or any breakdown by diabetes status, have not been reported in the published abstract ^[1]. Whether the findings change prescribing or insurance coverage in the United States was not addressed in the publication ^[1].