This section highlights FDA-related milestones and regulatory updates for drugs developed by Rein Therapeutics (RNTX).
Over the past two years, Rein Therapeutics has reported clinical trial outcomes, regulatory submissions, approvals, and other FDA events for drugs and therapies such as
LTI-03 and LTI-2355. For definitions of regulatory abbreviations such as NDA, BLA, or PDUFA, see the event status legend.
Select a button below to view the list of FDA events for that drug.
LTI-03 FDA Regulatory Timeline and Events
LTI-03 is a drug developed by Rein Therapeutics for the following indication: In Idiopathic Pulmonary Fibrosis.
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- LTI-03
- Announced Date:
- April 29, 2026
- Indication:
- In Idiopathic Pulmonary Fibrosis
Announcement
Rein Therapeutics today provided an update on its ongoing Phase 2 RENEW clinical trial evaluating LTI-03 for the treatment of idiopathic pulmonary fibrosis (IPF).
AI Summary
Rein Therapeutics updated its Phase 2 RENEW trial of LTI-03 for idiopathic pulmonary fibrosis (IPF). Enrollment is accelerating: 8 patients have been enrolled and two more are expected this week. The study began in March 2026 and continues to add patients regularly. Sites are active in the United States, Australia and Poland; the company expects to open sites in the UK and Germany soon and plans to open more. CEO Brian Windsor said they are pleased with the progress.
RENEW is a randomized, placebo-controlled Phase 2 trial testing the safety, tolerability and efficacy of inhaled LTI-03 in 120 patients randomized to two dose levels or placebo. The main endpoint is change from baseline in forced vital capacity (FVC). LTI-03 is a first-in-class inhaled peptide based on Caveolin‑1 biology designed to limit lung scarring while preserving alveolar progenitor cells; early data suggest it may slow fibrosis and promote healing.
Read Announcement- Drug:
- LTI-03
- Announced Date:
- March 3, 2026
- Indication:
- In Idiopathic Pulmonary Fibrosis
Announcement
Rein Therapeutics announced that it has dosed the first patient in its Phase 2 clinical trial evaluating LTI-03 for idiopathic pulmonary fibrosis (IPF), a progressive and fatal lung disease with limited treatment options.
AI Summary
Rein Therapeutics announced it has dosed the first patient in a Phase 2 trial of LTI-03 for idiopathic pulmonary fibrosis (IPF), a progressive and often fatal lung disease. The randomized study will enroll about 120 patients across placebo, low-dose, and high-dose arms at sites in five countries. The trial will assess safety and tolerability and will closely track lung function measures such as forced vital capacity (FVC).
The study is active at five U.S. sites and plans to expand to as many as 50 sites, with enrollment expected through mid-2027 and interim data anticipated in the second half of 2026. LTI-03 is designed to mimic Caveolin-1, targeting multiple fibrotic pathways and supporting alveolar epithelial progenitor cells to address underlying drivers of fibrosis. IPF affects roughly 100,000 people in the U.S. each year and typically leads to serious loss of lung function and a median survival of 3–5 years after diagnosis.
Read Announcement- Drug:
- LTI-03
- Announced Date:
- January 20, 2026
- Indication:
- In Idiopathic Pulmonary Fibrosis
Announcement
Rein Therapeutics announced that it has received orphan drug designation from the European Medicines Agency (EMA) for LTI-03, its lead drug candidate aimed at preserving lung function in patients with idiopathic pulmonary fibrosis (IPF).
AI Summary
Rein Therapeutics announced that the European Medicines Agency (EMA) has granted orphan drug designation to LTI-03, its lead candidate aimed at preserving lung function in patients with idiopathic pulmonary fibrosis (IPF). The designation followed a positive opinion from the EMA’s Committee for Orphan Medicinal Products and adoption by the European Commission, reflecting the seriousness of IPF and the need for new treatments for this rare, progressive lung disease.
The EMA’s decision was supported by preclinical data showing improved survival and lung function, and regulators agreed LTI-03 could offer a meaningful benefit compared with existing therapies. Orphan status in the EU provides incentives such as reduced development fees, possible market exclusivity after approval, and streamlined regulatory interactions. LTI-03 is now listed in the EU Community Register of Orphan Medicinal Products under designation number EU/3/25/3188.
Read Announcement- Drug:
- LTI-03
- Announced Date:
- November 6, 2025
- Indication:
- In Idiopathic Pulmonary Fibrosis
Announcement
Rein Therapeutics announced that a new preprint has been posted to medRxiv describing clinical and translational findings from an inhaled, dose-escalation study of Rein's lead drug candidate, LTI-03, in idiopathic pulmonary fibrosis (IPF).
AI Summary
Rein Therapeutics has published a new preprint on medRxiv detailing results from a first-in-human, inhaled dose-escalation study of its lead drug candidate, LTI-03, in patients with idiopathic pulmonary fibrosis (IPF). The report shows that inhaled LTI-03 was well tolerated across multiple dose levels and achieved measurable lung exposure.
Analysis of patient samples revealed significant reductions in several fibrosis-linked biomarkers, suggesting that the drug effectively engages its targets in lung tissue. Importantly, LTI-03 appeared to preserve alveolar epithelial type II (AT2) progenitor cells, which are vital for lung repair and regeneration. Current IPF treatments mainly slow disease progression, whereas LTI-03’s dual action may both inhibit scarring and support cell survival.
These encouraging translational findings support Rein’s decision to advance LTI-03 into its ongoing Phase 2 RENEW trial, where researchers will further evaluate safety, optimal dosing, and clinical benefit in a larger IPF patient group.
Read Announcement- Drug:
- LTI-03
- Announced Date:
- November 3, 2025
- Indication:
- In Idiopathic Pulmonary Fibrosis
Announcement
Rein Therapeutics announced that the U.S. Food and Drug Administration (FDA) has lifted the full clinical hold on the Company's Phase 2 "RENEW" trial evaluating LTI-03 in patients with idiopathic pulmonary fibrosis (IPF).
AI Summary
Rein Therapeutics announced that the U.S. Food and Drug Administration has lifted the full clinical hold on its Phase 2 “RENEW” trial of LTI-03 in patients with idiopathic pulmonary fibrosis (IPF). The FDA’s decision allows the study, identified as LTI-03-2001, to move forward after reviewing Rein’s responses and confirming that all concerns have been resolved.
The company plans to restart U.S. patient enrollment in late 2025 or early 2026 at about 20 clinical sites. This effort is part of Rein’s global RENEW program to test safety, tolerability, and efficacy in up to 120 IPF patients.
Rein’s CEO, Brian Windsor, said the cleared clinical hold is a major milestone. He added that LTI-03 could not only slow lung fibrosis but also support tissue repair, offering a potentially new approach to treating IPF.
Early data show that LTI-03 may act in two ways: reducing scar tissue and promoting lung healing. Topline results from this trial are expected in the third quarter of 2026.
Read Announcement
LTI-2355 FDA Regulatory Events
LTI-2355 is a drug developed by Rein Therapeutics for the following indication: In Idiopathic Pulmonary Fibrosis (IPF) and Post-Acute Sequelae of COVID Fibrosis (PASC-F).
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- LTI-2355
- Announced Date:
- April 15, 2025
- Indication:
- In Idiopathic Pulmonary Fibrosis (IPF) and Post-Acute Sequelae of COVID Fibrosis (PASC-F)
Announcement
Rein Therapeutics announced a publication highlighting the therapeutic potential of Caveolin-1-related peptide LTI-2355 in Idiopathic Pulmonary Fibrosis (IPF) and Post-Acute Sequelae of COVID Fibrosis (PASC-F) in the peer-reviewed journal, Biomedicines.
AI Summary
Rein Therapeutics recently published a study in the peer-reviewed journal Biomedicines that highlights the potential of their Caveolin-1-related peptide, LTI-2355, for treating lung fibrosis. The study focused on two serious conditions: Idiopathic Pulmonary Fibrosis (IPF) and Post-Acute Sequelae of COVID Fibrosis (PASC-F).
The research showed that LTI-2355, a stable 13-amino acid peptide, improved the phagocytic ability of lung myeloid cells, allowing them to better fight infections. At the same time, the peptide reduced the inflammatory and fibrotic responses of these key cells, which are linked to the worsening of lung fibrosis. Authored by Rein Therapeutics’ scientists along with collaborators from Cedars-Sinai Medical Center and Duke University, the study supports the promise of LTI-2355 as a therapeutic option for lung fibrosis patients.
Read Announcement
