Rein Therapeutics, Inc. filed a Current Report on Form 8-K with the Securities and Exchange Commission on September 4, 2026, to disclose updated presentation materials regarding its LTI-03 product candidate. The company posted the presentation to its investor relations website, providing an overview of the science behind the therapy.
The filing details LTI-03 as a seven-amino acid peptide derived from the caveolin scaffolding domain (CSD) of Caveolin-1. Rein Therapeutics states that LTI-03 is the smallest CSD fragment that retains functionality and is designed to mimic the regulatory activity of Caveolin-1. The company notes that Caveolin-1 is downregulated in fibrotic states, and LTI-03 aims to affect phosphorylation of dozens of profibrotic proteins involved in multiple fibrosis pathways.
The presentation highlights that LTI-03 is administered via a dry powder inhaler for direct lung delivery. The company reports that the therapy has demonstrated antifibrotic and regenerative properties in preclinical models, including attenuating fibrosis in cardiac and dermal models. The document emphasizes that LTI-03 has a dual mechanism of action, inhibiting profibrotic signaling while supporting alveolar epithelial cell survival.
Regarding clinical data, the filing states that a Phase 1b clinical trial for LTI-03 met its primary endpoint. The company reports that both the high dose (10mg) and low dose (5mg) were well-tolerated, with no treatment-related serious adverse events (SAEs) observed. The presentation notes that 5 biomarkers reached nominal significance at the higher dose and 2 at the lower dose. The company indicates that these biomarkers were directionally consistent with preclinical findings.
Rein Therapeutics states that LTI-03 is now enrolling the RENEW Phase 2 clinical trial (NCT06968845). The company also outlines a pipeline of other programs, including LTI-01 for loculated pleural effusion and LTI-05 for cystic fibrosis.
The filing includes a section on risk factors, noting that the company’s present cash and cash equivalents may not be sufficient to fund operations into the first quarter of 2028. The company cautions that actual results may differ materially from those indicated by forward-looking statements due to risks associated with clinical trials and commercialization.
