Rein Therapeutics (RNTX) Study Result summary

Study design and patient population

• Phase 1b trial evaluated LTI-03 in 24 IPF patients (18 active, 6 placebo), randomized to receive LTI-03 or placebo for 14 days via dry powder inhalation, including both treatment-naive and previously treated patients after a washout period.

• The study used a randomized, double-blind, placebo-controlled, multi-center, dose escalation design with low and high dose cohorts.

• Patients underwent bronchoscopies and biomarker sampling at baseline and after treatment.

• Primary endpoint was safety and tolerability; exploratory endpoints included biomarker analysis from blood, BAL, and brushings.

• Statistical significance for biomarker changes was set at p < 0.05.

Key efficacy and biomarker findings

• Dose-dependent effects observed in five biomarkers: COL1A1, CXCL7, TSLP, GAL7, and SPD, indicating active pharmacodynamics.

• Statistically significant reductions in CXCL7, TSLP, and GAL7 in Cohort 2; combined data showed significance for IL-11, CXCL7, TSLP, and GAL7.

• Surfactant protein D (SPD), a marker of epithelial cell health, decreased by 5% after 14 days, comparable to a 4% reduction at 12 weeks with nintedanib (OFEV®) in prior studies.

• COL1A1 showed a dose-dependent decrease, though not statistically significant.

• Biomarker changes suggest LTI-03 impacts both pro-fibrotic pathways and epithelial cell health.

Safety and tolerability

• No major safety signals or drug-related adverse events observed; only minor adverse events such as mild cough.

• LTI-03 did not induce inflammation, as measured by lack of pAKT activation in PBMCs.

• LTI-03 was well tolerated, supporting advancement to phase II.