---
schema_version: "secwatch.filing_event.v1"
accession: "0000879407-26-000004"
form_type: "8-K"
ticker: "ARWR"
cik: "0000879407"
company_name: "ARROWHEAD PHARMACEUTICALS, INC."
filed_at: "2026-01-06T23:59:59+00:00"
generated_at: "2026-05-16T11:36:24.752388+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.85
calibrated_materiality_score: 0.85
confidence: "high"
source: SEC EDGAR
---

# Arrowhead reports Phase 1/2a data: ARO-INHBE + tirzepatide doubles weight loss in obese T2DM patients

## Summary
- ARO-INHBE + tirzepatide (n=4) achieved -9.4% weight loss at week 16 vs -4.8% with tirzepatide alone; visceral fat -23.2% vs -7.4%.
- ARO-INHBE monotherapy: single dose reduced visceral fat -9.9% at week 16; two doses gave -15.6% placebo-adjusted at week 24.
- ARO-ALK7 is first RNAi to silence an adipocyte gene; mean ALK7 mRNA reduction -88% at 200 mg; visceral fat -14.1% at week 8.
- Both candidates generally well tolerated; no discontinuations; one unrelated SAE (limb abscess) in ARO-INHBE group.
- Company expects additional results from these ongoing Phase 1/2a studies later in 2026.

## SEC filing metadata
- accession: 0000879407-26-000004
- form_type: 8-K
- ticker: ARWR
- cik: 0000879407
- company_name: ARROWHEAD PHARMACEUTICALS, INC.
- filed_at: 2026-01-06T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.85
- calibrated_materiality_score: 0.85
- confidence: high
- sec_items: 7.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/879407/000087940726000004/0000879407-26-000004-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/879407/000087940726000004/arwr-20260106.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0000879407-26-000004
- JSON: https://secwatch.observer/filing/0000879407-26-000004.json
- Plain text: https://secwatch.observer/filing/0000879407-26-000004.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.