NCT06968845 · Rein Therapeutics
A Phase 2 Study of LTI-03 in Patients With Idiopathic Pulmonary Fibrosis
What this study is about
Rationale: LTI-03 is an experimental medication breathed into the lungs using an inhaler. It is being studied for the treatment of Idiopathic Pulmonary Fibrosis (IPF). IPF is a progressive, fatal lung disease caused by the death of lung cells involved in oxygen uptake and by progressive fibrosis (scarring) of the lungs.
View original scientific description
Rationale: LTI-03 is an experimental medication breathed into the lungs using an inhaler. It is being studied for the treatment of Idiopathic Pulmonary Fibrosis (IPF). IPF is a progressive, fatal lung disease caused by the death of lung cells involved in oxygen uptake and by progressive fibrosis (scarring) of the lungs. As the disease progresses, patients experience loss of lung function and increased breathing problems. LTI-03 is hypothesized to treat IPF by protecting and restoring the function of the oxygen uptake cells and by controlling lung fibrosis which may result in improving lung scarring. The purpose of this research is to evaluate LTI-03 including: its safety, whether it causes side effects, whether it improves lung scarring, and whether it improves IPF symptoms. LTI-03 will be compared to placebo in patients diagnosed with IPF within the last 5 years. Patients on a stable dose of nintedanib, pirfenidone, or nerandomilast (if available by prescription) may participate. Trial Design: This is a Phase 2, randomized, double-blind, placebo-controlled, multi-center study that includes a 28-day Screening Period, a 24-week Treatment Period, and 4-week Follow-up Period. Study Assessments: Up to 9 visits to the study clinic will be required. Safety and tolerability will be evaluated with the following assessments: physical examination; collection of vital sign data (heart rate, blood pressure, respiratory rate and peripheral oxygen saturation \[SpO2\] via pulse oximetry); heart data collected by 12-lead electrocardiogram; and collection of blood samples for safety laboratory tests. In addition, participants will be asked about any adverse events (side effects) they have experienced between clinic visits, if they have changed any medications, and if they are able to properly use their study drug inhaler. Participants will undergo a lung function test (spirometry) at every visit, which will be used to evaluate both safety and efficacy. Another test measuring the diffusion capacity of the lungs for carbon monoxide (DLCO) will be required at Screening only. Blood samples will also be collected at each visit to measure disease biomarkers. At select visits patients will be asked to complete the Living with Pulmonary Fibrosis questionnaire to evaluate their IPF symptoms. Participants will also undergo a specialized lung scan (HRCT) at Baseline and at the End of Treatment to measure changes in lung fibrosis. Interventions: LTI-03 and placebo are provided in powder-filled capsules that participants will self- administer using an inhaler. Placebo capsules look like LTI-03 capsules but have no active ingredients. Approximately 120 participants will be randomly assigned in a blinded manner to one of study drug treatment groups.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Male or female age 40 years or older.
- Willing and able to provide written informed consent.
- Diagnosis of IPF within 5 years of Screening as confirmed by a centrally read HRCT of the chest as defined by the ATS/ERS/JRS/ALAT guideline. HRCT lung fibrosis by central read during screening must involve ≥ 10% of the lung and be greater than emphysema involvement of the lung.
- Forced vital capacity (FVC) percent predicted ≥ 45% at Screening.
- Diffusion capacity of the lungs for carbon monoxide (DLCO), hemoglobin-corrected percent predicted ≥ 30% within 8 weeks prior to Randomization.
- Participants receiving nintedanib, pirfenidone, or nerandomilast (where approved for marketing) for IPF treatment must have been on a stable prescribed dose for at least 12 weeks prior to Randomization.
- Participants who previously received nintedanib, pirfenidone, or nerandomilast must have discontinued treatment at least 8 weeks prior to Randomization.
- Able to adequately self-administer study drug using the protocol-specified inhaler device.
Exclusion criteria
- Forced expiratory volume in 1 second (FEV1)/FVC \< 0.7 at Screening.
- Use of N-acetyl cysteine or other supplements including but not limited to quercetin, omega-3 fatty acids, dehydroepiandrosterone, polyphenols, and phytochemicals within 7 days prior to Randomization and through Week 24.
- Use of systemic corticosteroids at doses \> 10 mg/day of prednisone or equivalent within 28 days prior to Randomization.
- Active smoker.
- Pulmonary exacerbation within 3 months prior to Screening.
- Febrile pulmonary illness requiring antibiotic treatment within 28 days prior to Randomization.
- Participation in a clinical study or treatment with an investigational drug or device within 28 days of the Screening Visit (or 5 half-lives of the investigational agent, whichever is longer).
- History or evidence at Screening of significant renal impairment with estimated glomerular filtration rate (eGFR) \< 30 mL/min/1.73m2.
- History or evidence at Screening of significant hepatic impairment with bilirubin \> 3 mg/dL (\> 51.3 μmol/L) and albumin \< 2.8 g/dL (\<28 g/L) and PT prolongation \> 6 sec or INR \> 2.3 while not on anticoagulant medication.
- Active or history of malignancies within 5 years prior to Randomization, with the exception of localized nonmetastatic basal or squamous cell carcinoma of the skin, in situ carcinoma of the cervix, or prostate cancer.
- Serious or active medical or psychiatric condition which, in the opinion of the Investigator, may interfere with treatment, assessment, or compliance with the protocol; or an expected survival of less than 24 weeks. Contraception and Pregnancy
- Positive pregnancy test in female participants of childbearing potential (defined below).
- Female participants who are lactating.
- Females of childbearing potential (FOCBP) and men with partners of childbearing potential who do not agree to use an acceptable form of contraception for the duration of study treatment and for at least 90 days after the last dose of study drug. Male participants who do not agree to refrain from donating sperm during this same period.
Where
- Birmingham, Alabama
- Los Angeles, California
- San Diego, California
- Denver, Colorado
- New Haven, Connecticut
- Weston, Florida
- Detroit, Michigan
- Chesterfield, Missouri
- Kansas City, Missouri
- Chapel Hill, North Carolina
- Charleston, South Carolina
- El Paso, Texas
And 1 more location — see the full list below.
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jul 6, 2026 · Source of record for eligibility and locations