Arrowhead Pharmaceuticals published early clinical signals showing its RNAi candidates reduced visceral and liver fat when dosed in combination with Lilly’s tirzepatide (Zepbound). The company reported meaningful reductions in body fat compartments and metabolic biomarkers in initial cohorts, supporting progression of the programs toward Phase 2. Data showed combination-treated patients experienced greater fat-loss and liver-fat clearance than peers on tirzepatide alone. Arrowhead described the readouts as proof-of-concept for targeted adipose delivery of RNAi therapeutics and plans to expand trials to evaluate durability, safety, and broader metabolic outcomes.