This study will assess the safety and tolerability of inhaled LTI-03 in treatment naïve participants with newly diagnosed IPF.

This is a randomized, double-blind, placebo controlled, multi-center, dose escalation, safety and tolerability study of LTI-03 or placebo administered by inhalation in participants recently diagnosed with idiopathic pulmonary fibrosis that have not received prior treatment with anti-fibrotic agents.

The study will contain 2 dose cohorts which will run sequentially.

Eligible participants will be randomized in a 3:1 ratio to either LTI-03 or placebo. Safety data will be reviewed on an ongoing basis. Enrollment in the second cohort will not begin until the Cohort 1 safety data has been reviewed.

The Treatment Period will be 14 days, with subjects self-administering study drug using a provided commercially available dry-powder inhaler.

Inclusion Criteria:

1. Male or female subject of age 40 years or older.
2. Willing and able to provide written informed consent.
3. Diagnosis of IPF within 3 years of Screening as confirmed by HRCT of chest or lung biopsy as defined by ATS/ERS/JRS/ALAT guideline.
4. Forced vital capacity (FVC) percent predicted ≥ 40%.
5. Diffusion capacity of the lungs for carbon monoxide (DLCO) percent predicted ≥ 30 and ≤ 80.
6. Forced expiratory volume 1 (FEV1)/FVC ≥ 0.7.

Exclusion Criteria:

1. Interstitial lung disease other than IPF.
2. Evidence of significant obstructive lung disease.
3. Current diagnosis of asthma.
4. Treatment with an approved or investigational antifibrotic therapy for IPF within 2 months of the Baseline bronchoscopy.
5. Use of N-acetyl cysteine or other supplements within 7 days prior to dosing and throughout the Treatment Period.
6. Inability to use study inhaler device appropriately.
7. Pulmonary exacerbation within 6 months prior to Screening.
8. Febrile illness within 7 days prior to dosing.
9. Participation in a clinical study or treatment with an investigational drug or device within 30 days of the Screening Visit (or 5 half-lives of the investigational agent, whichever is longer).
10. History or evidence at screening of significant renal impairment with eGFR < 30 mL/min (region specific).
11. 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 (region specific).
12. Serious or active medical or psychiatric condition which, in the opinion of the Investigator, may interfere with treatment, assessment, or compliance with the protocol.
13. Vaccination within 2 weeks of start of dosing (Day 1) and throughout the Treatment Period.
14. Subject has severe progressive or uncontrolled, clinically significant disease that in the judgment of the investigator or designee renders the subject unsuitable for the study.
15. Positive urine pregnancy test in female subjects of childbearing potential as defined below.
16. Female subjects who are lactating.
17. 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 subjects who do not agree to refrain from donating sperm during this same period.

From ICF (if serious or related to protocol assessment) or Dosing Day 1 through End of Study Day 21

The Sponsor, Investigator, and study personnel working on behalf of the Investigator and Sponsor will remain blinded.