A Phase 2 Study of LTI-03 in Patients With Idiopathic Pulmonary Fibrosis

Last updated: March 30, 2026
Sponsor: Rein Therapeutics
Overall Status: Active - Recruiting

Phase

2

Condition

Scar Tissue

Lung Injury

Cystic Fibrosis

Treatment

Dry Powder Inhaler

Placebo

LTI-03

Clinical Study ID

NCT06968845
LTI-03-2001 (RENEW)
  • Ages > 40
  • All Genders

Study Summary

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.

Eligibility Criteria

Inclusion

Inclusion Criteria:

  1. Male or female age 40 years or older.

  2. Willing and able to provide written informed consent.

  3. Diagnosis of IPF within 5 years of Screening as confirmed by a centrally read HRCTof the chest as defined by the ATS/ERS/JRS/ALAT guideline. HRCT lung fibrosis bycentral read during screening must involve ≥ 10% of the lung and be greater thanemphysema involvement of the lung.

  4. Forced vital capacity (FVC) percent predicted ≥ 45% at Screening.

  5. Diffusion capacity of the lungs for carbon monoxide (DLCO), hemoglobin-correctedpercent predicted ≥ 30% within 8 weeks prior to Randomization.

  6. Participants receiving nintedanib, pirfenidone, or nerandomilast (where approved formarketing) for IPF treatment must have been on a stable prescribed dose for at least 12 weeks prior to Randomization.

  7. Participants who previously received nintedanib, pirfenidone, or nerandomilast musthave discontinued treatment at least 8 weeks prior to Randomization.

  8. Able to adequately self-administer study drug using the protocol-specified inhalerdevice.

Exclusion

Exclusion Criteria:

  1. Forced expiratory volume in 1 second (FEV1)/FVC < 0.7 at Screening.

  2. Use of N-acetyl cysteine or other supplements including but not limited toquercetin, omega-3 fatty acids, dehydroepiandrosterone, polyphenols, andphytochemicals within 7 days prior to Randomization and through Week 24.

  3. Use of systemic corticosteroids at doses > 10 mg/day of prednisone or equivalentwithin 28 days prior to Randomization.

  4. Active smoker.

  5. Pulmonary exacerbation within 3 months prior to Screening.

  6. Febrile pulmonary illness requiring antibiotic treatment within 28 days prior toRandomization.

  7. Participation in a clinical study or treatment with an investigational drug ordevice within 28 days of the Screening Visit (or 5 half-lives of the investigationalagent, whichever is longer).

  8. History or evidence at Screening of significant renal impairment with estimatedglomerular filtration rate (eGFR) < 30 mL/min/1.73m2.

  9. 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 secor INR > 2.3 while not on anticoagulant medication.

  10. Active or history of malignancies within 5 years prior to Randomization, with theexception of localized nonmetastatic basal or squamous cell carcinoma of the skin,in situ carcinoma of the cervix, or prostate cancer.

  11. Serious or active medical or psychiatric condition which, in the opinion of theInvestigator, may interfere with treatment, assessment, or compliance with theprotocol; or an expected survival of less than 24 weeks. Contraception and Pregnancy

  12. Positive pregnancy test in female participants of childbearing potential (definedbelow).

  13. Female participants who are lactating.

  14. Females of childbearing potential (FOCBP) and men with partners of childbearingpotential who do not agree to use an acceptable form of contraception for theduration of study treatment and for at least 90 days after the last dose of studydrug. Male participants who do not agree to refrain from donating sperm during thissame period.

Study Design

Total Participants: 120
Treatment Group(s): 3
Primary Treatment: Dry Powder Inhaler
Phase: 2
Study Start date:
February 02, 2026
Estimated Completion Date:
December 31, 2027

Connect with a study center

  • Launceston Respiratory and Sleep Centre

    Launceston, Tasmania 7250
    Australia

    Active - Recruiting

  • UAB Lung Health Center

    Birmingham, Alabama 35233
    United States

    Active - Recruiting

  • UAB Lung Health Center

    Birmingham 4049979, Alabama 4829764 35233
    United States

    Site Not Available

  • Paradigm Clinical Research Centers, LLC

    San Diego, California 92108
    United States

    Active - Recruiting

  • Paradigm Clinical Research Centers, LLC

    San Diego 5391811, California 5332921 92108
    United States

    Site Not Available

  • Henry Ford Health

    Detroit, Michigan 48202
    United States

    Active - Recruiting

  • The Lung Research Center, LLC

    Chesterfield, Missouri 63017
    United States

    Active - Recruiting

  • The Lung Research Center, LLC

    Chesterfield 4381072, Missouri 4398678 63017
    United States

    Site Not Available

  • Medical University of South Carolina

    Charleston, South Carolina 29425
    United States

    Active - Recruiting

  • Medical University of South Carolina

    Charleston 4574324, South Carolina 4597040 29425
    United States

    Site Not Available

  • El Paso Pulmonary Association

    El Paso, Texas 79902
    United States

    Active - Recruiting

  • El Paso Pulmonary Association

    El Paso 5520993, Texas 4736286 79902
    United States

    Site Not Available

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