ActRII-Blocking Antibody May Be a Novel Medicine for Obesity

ActRII-Blocking Antibody May Be a Novel Medicine for Obesity TrialsiteN

A January 13 study published in JAMA Network Open looks at the “Effect of Bimagrumab vs. Placebo on Body Fat Mass Among Adults With Type 2 Diabetes and Obesity.” This phase 2 RCT looked and asked, “What are the effects of bimagrumab, an antibody that blocks activin type II receptors and stimulates skeletal muscle growth on total body fat mass and glycemic control in patients with type 2 diabetes and excess adiposity?” The findings were notable: 75 patients with type 2 diabetes and a BMI from 28-40 got bimagrumab or a placebo over 48 weeks with all participants receiving diet and exercise advice, and those who got the drug, “had a significantly larger decrease in total body fat mass and glycated hemoglobin and increase in lean mass, compared with patients who received placebo.” The authors suggest that this result is due to a blockade of the activin receptor, which may provide “a novel pharmacologic approach for managing patients with type 2 diabetes with excess adiposity.” And prior studies have shown improved insulin resistance and adipose tissue loss with bimagrumab.

Novel Help for Excess Adiposity

The study (NCT03005288) sought to “evaluate the efficacy and safety of bimagrumab on body composition and glycemic control in adults with type 2 diabetes and overweight and obesity.” It was a double-masked and placebo-controlled 48-week phase 2 RCT, and the subjects were adults with type-2 diabetes and a BMI between 28 and 40. The trial was run from 2017 to 2019 at US and UK sites. Per the researchers, ActRII blockade from the bimagrumab led to substantial gains in lean mass and substantial loss of fat mass along with specific metabolic improvements. And they suggest that this ActRII pathway inhibition may be a new and novel pharmacologic help for “excess adiposity,” i.e., too much fat. The study’s limitations include a modest study size, the exclusion of healthy people, and gender imbalance in randomization. The corresponding author for the study is Steven B. Heymsfield, M.D., of the Pennington Biomedical Research Center, Louisiana State University in Baton Rouge.