Rein Therapeutics (RNTX) investor relations material

Disease overview and unmet need

• Idiopathic pulmonary fibrosis (IPF) is a fatal disease affecting about 100,000 people in the U.S., with 50,000 new cases and deaths annually.

• Median survival after diagnosis is only three to five years, worse than many cancers.

• Existing approved drugs only slow disease progression for one to two years and have severe side effects, leading to high discontinuation rates.

• The market-leading drug generates $4 billion in sales but is poorly tolerated by half of patients.

• There is a significant need for therapies that address both lung scarring and restoration of lung health.

Drug mechanism and innovation

• LTI-03 is a novel agent with a dual mechanism: inhibiting pro-fibrotic proteins and preserving Type 2 epithelial progenitor cells that can regenerate lung tissue.

• The drug mimics a portion of the caveolin-1 protein, restoring its regulatory function lost in fibrotic states.

• LTI-03 binds to caveolin binding domains, affecting phosphorylation and promoting homeostasis in lung cells.

• Demonstrated anti-fibrotic effects comparable to the market leader, nintedanib, but without observed toxicity.

• The mechanism has shown efficacy in models of fibrosis in multiple organs, suggesting broad potential.

Clinical development and results

• Two clinical trials completed: phase I-A in healthy volunteers and phase I-B in IPF patients, both showing safety and target engagement.

• Phase I-B used deep bronchial brushings to confirm drug delivery and biomarker changes in fibrotic lung tissue.

• Statistically significant reductions in key pro-fibrotic biomarkers, including IL-11, were observed in patient lungs.

• Plasma biomarker SP-D was reduced by 5% in two weeks, matching or exceeding reductions seen with approved drugs over 12 weeks.

• Preservation and increased viability of Type 2 progenitor cells were confirmed, supporting the drug’s regenerative claims.