Peptide News Digest

#Rntx

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Research · View digest

Rein Therapeutics Presents Inhaled LTI-03 Phase 1b Dose-Escalation Poster at ERS Congress Following Nature Communications Publication; First Synthetic Caveolin-1 Peptide for IPF Reduces IL-11 and TSLP

Rein Therapeutics (NASDAQ: RNTX) presented Tuesday September 8, 2026 (poster PA6217, 12:30-2:00 p.m. CEST) at the European Respiratory Society Congress in Barcelona the Phase 1b randomized double-blind placebo-controlled dose-escalation study of inhaled LTI-03 in patients with idiopathic pulmonary fibrosis. LTI-03 is a first-in-class synthetic seven-amino-acid peptide derived from the caveolin-1 scaffolding domain (CSD), designed with a dual mechanism targeting alveolar epithelial cell survival and inhibition of profibrotic signaling. The trial randomized 24 IPF participants 3:1 to LTI-03 5 mg/day (N=9), LTI-03 10 mg/day (N=9), or placebo (N=6) for 14 days. LTI-03 was well-tolerated with no treatment-related discontinuations, no severe TEAEs, and no spirometry-based airway obstruction; both doses significantly reduced interleukin-11 (p=0.0406 at 5 mg/day; p=0.044 at 10 mg/day) and thymic stromal lymphopoietin. The results were published the same day in Nature Communications (Philip Molyneaux MD, Imperial College London, presenting). LTI-03 has FDA Orphan Drug and Fast Track designations (Fast Track granted August 2026); the Phase 2 RENEW trial is enrolling across five countries with interim data anticipated H2 2026.

Regulatory · View digest

Rein Therapeutics LTI-03 UK MHRA Phase II Clearance for RENEW Trial in Idiopathic Pulmonary Fibrosis; Caveolin-1 Peptide Mimetic Class

Rein Therapeutics (NASDAQ: RNTX) received UK Medicines and Healthcare products Regulatory Agency (MHRA) clearance in August 2026 to initiate the Phase 2 RENEW study of LTI-03 (a Caveolin-1 scaffolding domain peptide mimetic developed for the treatment of idiopathic pulmonary fibrosis, or IPF). The RENEW study is planned to enroll 120 patients with IPF and evaluate LTI-03 as an add-on to standard-of-care antifibrotic therapy (pirfenidone or nintedanib). The Caveolin-1 mimetic peptide mechanism engages the fibrotic signaling that emerges downstream of alveolar epithelial cell injury and has been characterized in preclinical fibrosis models. Rein Therapeutics is the successor entity to the 2024 reverse merger between Aileron Therapeutics and Lung Therapeutics, and LTI-03 is the lead clinical asset. The Phase 2 initiation extends the small-but-substantive peptide-therapeutic pipeline in fibrotic disease (Sitryx SIT-402, MediciNova ibudilast) beyond the incretin obesity focus that dominates recent peptide-industry headlines.