Arrowhead’s RNAi Obesity Programs ARO-INHBE and ARO-ALK7 Advance with Encouraging Phase 1/2a Data
Arrowhead announced interim Phase 1/2a data on January 6, 2026, for ARO-INHBE and ARO-ALK7, showing significant weight loss and fat reductions in obese patients with type 2 diabetes.239
ARO-INHBE combined with tirzepatide (Zepbound) achieved 9.4% weight loss at week 16 vs. 4.8% with tirzepatide alone, doubling weight loss and tripling reductions in visceral fat (-23.2%), total fat (-15.4%), and liver fat (-76.7%).23
ARO-ALK7 monotherapy showed dose-dependent adipose ALK7 mRNA reduction up to 88% at 200mg dose after 8 weeks, with placebo-adjusted 14.1% visceral fat reduction and good tolerability.234
Both drugs were well-tolerated with mostly mild adverse events; studies are ongoing with more data expected in 2026.23
Arrowhead's stock rose significantly after the announcement, from $63.88 to a high of $76.76 on January 6, 2026.2
Sources:
2. https://www.clinicaltrialsarena.com/news/arrowheads-rnai-based-obesity-drug-combo-shows-benefit-in-phase-i-iia-trial/
3. https://arrowheadpharma.com/news-press/arrowhead-pharmaceuticals-announces-interim-clinical-data-on-rnai-based-obesity-candidates-showing-weight-loss-in-obese-patients-with-diabetes-and-improved-measures-of-body-composition/
4. https://www.biospace.com/drug-development/arrowhead-enters-obesity-chat-by-doubling-tirzepatides-weight-loss-in-combo-study