Arrowhead Pharmaceuticals, Inc. (NASDAQ:ARWR) today announced that preclinical data on ARO-INHBE, an investigational RNAi-based medicine for the treatment of obesity and metabolic diseases, were presented at the American Diabetes Association (ADA) 84th Scientific Sessions, which were held June 21-24, in Orlando, FL, and virtually.

The preclinical results demonstrate that ARO-INHBE substantially silenced hepatic expression of the INHBE gene, which has been identified through large genetic studies as a promising target for next generation therapies to address obesity and metabolic diseases. Further, Arrowhead's preclinical research suggests that INHBE knockdown may potentially lead to a suppression in body weight gain, loss of fat mass, and preservation of lean mass. Arrowhead plans to file for regulatory clearance in late 2024 to begin clinical studies of ARO-INHBE.

"There has been a great deal of progress with new agents to treat obesity and metabolic diseases, but significant loss of lean mass and adverse gastrointestinal events at higher dose levels have necessitated the identification of new therapeutic strategies with novel mechanisms of action," said James Hamilton, M.D., chief of discovery and translational medicine at Arrowhead. "ARO-INHBE directly targets hepatic expression of the INHBE gene. Prior genetic studies have associated loss of function mutations in the INHBE gene with reduced levels of abdominal fat and an improved metabolic profile. Our preclinical data presented at ADA suggest that INHBE reduction with siRNA is a promising new approach to address obesity and metabolic diseases and strongly support advancing ARO-INHBE into clinical trials."

In pharmacological studies in obese and diabetic mouse models, INHBE siRNA administration resulted in multiple promising findings, including the following:

• 95% reduction in INHBE mRNA expression
• 19% suppression of body weight compared to saline controls
• 26% loss of fat mass
• Preservation of lean mass

In addition, co-treatment of tirzepatide with INHBE siRNA allowed for the use of a lower tirzepatide dose without compromising its therapeutic effect. These encouraging results suggest that ARO-INHBE has the potential to be a novel therapeutic for metabolic disease.