Rein Therapeutics RNTX · USD

In June 2024, we decided to temporarily delay clinical development of LTI-01 in an effort to focus our resources on clinical development of LTI-03 and until additional funds are raised. In the fourth quarter of 2024, we determined that the temporary delay of further clinical development of LTI-01 may not be a short-term measure. In the fourth quarter of 2025, we decided to pause development activities related to LTI-01 and preclinical programs targeting cystic fibrosis and a peptide program focused on the Cav1 protein for an indefinite period.

LTI-03 is a novel peptide drug, the sequence of which is derived from the endogenous protein Cav1, that protects lung epithelial cells and inhibits multiple pro-fibrotic pathways in IPF patients. IPF is a progressive, fatal, age-associated lung disease with a median survival from diagnosis of three to five years. There are approximately 100,000 people living with IPF in the U.S. LTI-03 has been granted Orphan Drug Designation in the U.S. and European Union, or EU, for the treatment of IPF.

The pathogenesis of IPF is characterized by the loss of healthy lung cells known as alveolar epithelial type 2 cells, or AEC2s, proliferation and accumulation of activated myofibroblasts, deposition of extracellular matrix, or ECM, and fibrosis, resulting in labored breathing and loss of lung function. Damaged AEC2s are unable to replace injured alveolar epithelial type 1 cells, or AEC1s, which make up the majority of the alveolar surface and are important in mucus clearance and healthy lung function.

Quoted from its 10-K, filed 26 Mar 2026. Read the filing on SEC.gov ↗