Does a GLP-1 receptor agonist offer the same weight-loss benefits to different racial subgroups?
The glucagon-like peptide (GLP)-1 receptor agonist liraglutide had similar efficacy for weight loss across racial subgroups, according to data taken from a post hoc analysis of data from five clinical trials comparing the drug with placebo.
“The efficacy and safety of liraglutide 3.0 mg for weight management were generally similar across races in this post hoc pooled analysis, with overall consistent positive effects on body weight, cardiometabolic risk factors, and health-related quality of life,” wrote researcher Jamy Ard, of Wake Forest Baptist Medical Center, and colleagues in Diabetes, Obesity and Metabolism.
“With liraglutide 3.0 mg, more than half the individuals across the racial subgroups achieved a clinically meaningful weight loss of at least 5%, which is associated with a variety of health benefits and improvements in obesity-related comorbidities such as diabetes and hypertension, as well as in quality of life and physical mobility.”
According to the study, obesity and overweight rates are more prevalent among black individuals than their white counterparts. Ard and colleagues conducted this study to determine if liraglutide had equally positive effects on weight loss across racial subgroups. To do this, they pooled data from four SCALE phase IIIa trials and one phase II trial. Their analysis included data from 5,325 adults with a body mass index (BMI) of 27 or greater plus one or more comorbidity, or a BMI of 30 or greater.
In these trials, weight loss was between 5.7% and 9.2% with liraglutide 3.0 mg. The mean BMI was lowest in Asian patients and highest in black/African-American patients.
The analysis showed a greater mean relative and absolute weight loss for patients assigned to liraglutide 3.0 mg compared with placebo across all racial subgroups. Greater mean weight loss at end of treatment occurred for all subgroups in patients assigned liraglutide compared with placebo (whites: 7.7% vs. 2.3%; blacks: 6.3% vs. 1.4%; Asians: 6.3% vs. 2.5%; other: 7.3% vs. 0.49%).
In addition, there were greater mean reductions in cardiovascular risk across all racial subgroups in patients assigned to liraglutide 3.0 mg compared with placebo.
“Overall, greater mean reductions in HbA1c and fasting plasma glucose with liraglutide 3.0 mg vs. placebo were generally observed across racial subgroups,” the researchers noted. “Whilst the test for interaction was statistically significant for both these glycaemic parameters in individuals with prediabetes, the differences between subgroups were minor and are unlikely to be clinically relevant.”
The researchers also looked at the safety of liraglutide and found similar proportions of patients reporting adverse events and serious adverse events among all racial subgroups examined.
“In each racial subgroup the most frequently reported events were gastrointestinal disorders, which were reported more frequently with liraglutide 3.0 mg than placebo,” the researchers wrote. “The proportion of individuals on liraglutide 3.0 mg discontinuing due to side-effects (mostly gastrointestinal disorders) was greater than that in the placebo group across racial subgroups.”
In their discussion of the results, Ard and colleagues noted that the clinical trials included in this post hoc analysis were not designed for comparisons across racial subgroups and that all trials included had disproportionately more white participants.
Reference: Ard J, et al. The efficacy and safety of liraglutide 3.0 mg for weight management are similar across races: subgroup analysis across SCALE and phase 2 randomized trials. Diabetes Obes Metab. Epub 7 Jan 2016.