New research presented at this year’s European Congress on Obesity (held online, 10-13 May) shows that treatment with the drug semaglutide reduces body weight in adults with overweight or obesity, regardless of their baseline characteristics.

However, the study showed that female participants had slightly better results than males and also that participants with the lowest starting body weight responded slightly better than those with higher body weights. The study is by Professor Robert Kushner, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA, and colleagues.

Semaglutide is already approved for treatment for type 2 diabetes in multiple countries, and is under development for treatment of obesity. The STEP trials published over the past year have established the efficacy and safety of semaglutide 2.4 mg in treating people with overweight and obesity. In this new analysis of data from the STEP 1 trial (see link below), the researchers investigated weight loss in subgroups of participants based on their baseline characteristics.

In STEP 1, adults without type 2 diabetes with either a body mass index (BMI) of at least 27 kg/m² plus one or more weight-related comorbidities, or a BMI of 30 kg/m² or above, were enrolled. Participants were randomised to a once-weekly injection of semaglutide 2.4 mg or placebo, both plus lifestyle intervention, for 68 weeks.

The authors looked at what proportions of the participants achieved different levels of weight loss with semaglutide from baseline to week 68 (?20%, 15-<20%, 10-<15%, or 5-<10%) when grouped by different baseline characteristics (age, sex, race [White, Asian, Black or African American, or other], body weight, BMI, waist circumference and glycaemic status [normal blood sugar, or pre-diabetes]). Mean percent weight loss with semaglutide from baseline to week 68 was analysed separately by sex (male, female) and baseline body weight (?115 kg, 100-<115 kg, 90-<100 kg, <90 kg) subgroup.

The original study included 1,961 randomised participants (mean age 46 years, body weight 105.3 kg, BMI 37.9 kg/m²; 74.1% female). For categorical weight loss, the observed proportions of participants with ?20%, 15-<20%, 10-<15% and 5-<10% weight loss at week 68 were 34.8%, 19.9%, 20.0% and 17.6% with semaglutide vs 2.0%, 3.0%, 6.8% and 21.2% with placebo, respectively.

The distribution of participants across weight-loss groups did not appear to be affected by any baseline characteristics, except sex and baseline body weight. Mean percent weight loss at week 68 with semaglutide was greater among females (-18.4%) than males (-12.9%), and in participants with lower vs higher baseline body weight (-18.6% for participants with <90 kg body weight at baseline; -13.9% for participants with ?115 kg baseline body weight).

The authors conclude: “We found that weight loss with once-weekly injections of semaglutide 2.4 mg was seen in all subgroups evaluated and was generally not influenced by baseline characteristics. The exceptions were sex and baseline body weight; female sex and a low baseline body weight were associated with a slightly greater response to semaglutide. These data support the use of semaglutide 2.4 mg across a broad population of patients with overweight or obesity.”