Rein Therapeutics Receives FDA Clearance To Resume Phase 2 RENEW Trial Of LTI-03 In Patients With Idiopathic Pulmonary Fibrosis

Rein Therapeutics, a biopharmaceutical company developing first-in-class medicines for rare pulmonary and fibrotic diseases, has announced that the U.S. Food and Drug Administration (FDA) has lifted the full clinical hold on its Phase 2 “RENEW” trial evaluating LTI-03 in patients with idiopathic pulmonary fibrosis (IPF). This decision marks an important milestone for Rein, allowing the company to move forward with its global development program for LTI-03, a potential new therapy aimed at addressing the underlying mechanisms of fibrosis and promoting lung repair.

The FDA’s decision follows a detailed review of Rein’s response to the agency’s earlier concerns. In its official communication, the FDA confirmed that Study LTI-03-2001 may now proceed and that all issues leading to the previous full clinical hold have been satisfactorily resolved. This clearance enables Rein to resume patient enrollment and continue advancing its Phase 2 program as planned.

Commenting on the development, Brian Windsor, Ph.D., Chief Executive Officer of Rein Therapeutics, said, “This is a major milestone for our team and the LTI-03 program. The FDA’s decision allows us to restart enrollment and continue moving forward with our global Phase 2 RENEW trial. We’re grateful for the agency’s collaboration throughout this process and proud of our team’s commitment to addressing every concern thoroughly and efficiently. We believe LTI-03 has the potential to transform the treatment landscape for IPF by not only slowing the progression of fibrosis but also helping to restore lung function.”

Rein plans to resume patient recruitment in late 2025 or early 2026 across approximately 20 clinical sites in the United States. The study locations will include centers in Alabama, California, Colorado, Connecticut, Florida, Indiana, Kansas, Massachusetts, Michigan, Missouri, North Carolina, New York, Ohio, South Carolina, and Texas.

The U.S. arm of the trial will complement Rein’s broader international RENEW program, which includes about 30 additional sites across the United Kingdom, Germany, Poland, and Australia. The multicenter Phase 2 study is designed to evaluate the safety, tolerability, and efficacy of LTI-03 in up to 120 patients diagnosed with idiopathic pulmonary fibrosis, a progressive and life-threatening lung condition characterized by scarring of lung tissue and declining respiratory function.

Key secondary endpoints for the trial include changes in lung function (measured by forced vital capacity, or FVC), as well as imaging-based assessments of fibrosis progression. These outcomes will help determine the therapeutic potential of LTI-03 in improving disease management and patient quality of life. Rein anticipates initial topline data from the RENEW study to be available in the third quarter of 2026.

With the FDA’s clearance to proceed, Rein Therapeutics is positioned to accelerate the clinical development of LTI-03 as part of its broader mission to deliver innovative, disease-modifying therapies for patients suffering from orphan pulmonary and fibrotic diseases—areas where treatment options remain limited and unmet needs are high.