Arrowhead ARO-INHBE Plus Tirzepatide EASL 2026 Data Show Enhanced Visceral Fat and Liver Fat Reduction Versus Tirzepatide Alone
Arrowhead Pharmaceuticals (NASDAQ: ARWR) presented updated Phase 1/2a data on ARO-INHBE (an RNA interference therapeutic targeting Activin E) and ARO-ALK7 (RNAi targeting ALK7 receptor) at EASL 2026. Standalone data: ARO-INHBE monotherapy achieved mean visceral fat reduction of -9.9% at week 16 after a single dose and -15.6% placebo-adjusted after two doses at week 24, with a single dose increasing lean muscle tissue by 3.6%; ARO-ALK7 monotherapy achieved -14.1% placebo-adjusted visceral fat reduction at week 8 after a single dose. Combination data: ARO-INHBE plus low-dose tirzepatide (5 mg) enhanced reductions in visceral adipose tissue and liver fat content versus tirzepatide alone in participants with obesity with or without type 2 diabetes. Mean maximum Activin E reduction reached 85.3% at the 400 mg dose with persistent effect beyond 3 months. Additional 2026 readouts expected. The data extend the case for RNAi as a non-peptide, quarterly-dosed obesity add-on capable of shifting body composition rather than just body weight.