Peptide News Digest

#Tirzepatide-Combination

2 stories

Clinical Trials · View digest

Arrowhead Pharmaceuticals ARO-INHBE EASL 2026 (May 27): RNAi-Based Activin E/ALK7 Pathway Therapeutic Cuts Liver Fat 44% at ≥200 mg; Doubles Weight Loss + Triples Fat Reduction in Combination With Tirzepatide

Arrowhead Pharmaceuticals presented Phase 1/2a interim clinical data on ARO-INHBE at EASL 2026 today (Rinki Murphy, MBChB, PhD presenting). ARO-INHBE is an RNAi therapeutic targeting the Activin E/ALK7 pathway — a genetically validated regulator of adipose fat storage. The data: a single 400 mg dose produced 85.3% mean maximum Activin E reduction with persistent effect beyond 3 months; ≥200 mg doses reduced liver fat 44%. In combination with low-dose tirzepatide 5 mg in obese patients with type 2 diabetes, ARO-INHBE doubled weight loss and tripled reductions in visceral fat, total fat, and liver fat versus tirzepatide alone. Effect persists through Week 24 supporting potential twice-yearly dosing. Arrowhead is engaging with regulatory authorities on Phase 2 designs in MASH and obesity. The combination data is the strongest evidence to date that adding a non-GLP-1 mechanism to incretin therapy can meaningfully amplify body-composition outcomes — a contrast to the GLP-1-alone monotherapy story that has dominated obesity-pharmacology since 2021.

Clinical Trials · View digest

Scholar Rock Apitegromab + Tirzepatide EMBRAZE Phase 2: 54.9% Lean Mass Preservation Continues to Set Muscle-Sparing Bar

Scholar Rock's apitegromab — a selective pro/latent myostatin antibody approved for SMA — continues to draw obesity-pipeline attention with EMBRAZE Phase 2 data showing 54.9% relative lean mass preservation when combined with tirzepatide vs tirzepatide alone (4.2 lbs / 1.9 kg additional lean mass preserved, p=0.001). Body composition shifted from 70% fat/30% lean with tirzepatide alone to 85%/15% with the combination. SRK-439 next-gen selective myostatin inhibitor is in preclinical development with attenuation of fat-mass rebound after GLP-1 withdrawal as a key signal.