Study to evaluate HZN-825 in patients with Idiopathic Pulmonary Fibrosis (IPF)

Inclusion Criteria:

1. Diagnosis of IPF, as defined by American Thoracic Society (ATS)/European Respiratory Society (ERS)/Japanese Respiratory Society (JRS)/Latin American Thoracic Society (ALAT) guidelines [Raghu et al., 2018]; the date of diagnosis of IPF should be ≥1 year to ≤7 years prior to Screening.

2. Lung HRCT historically performed within 6 months prior to the Screening Visit and according to the minimum requirements for IPF diagnosis by central review based on subject's HRCT. If an evaluable HRCT is not available within 6 months prior to Screening, an HRCT will be performed at Screening to determine eligibility, according to the same requirements as the historical HRCT

3. HRCT shows ≥10% to <50% parenchymal fibrosis (reticulation) and <25% honeycombing and the extent of fibrotic changes is greater than the extent of emphysema on the most recent HRCT scan (central reviewer determined)

4. Meets all of the following criteria during the Screening Period: FVC ≥45% and ≤80% predicted of normal, forced expiratory volume in 1 second (FEV1)/FVC ≥0.7, DLCO corrected for hemoglobin is ≥30% and ≤90% predicted of normal

5. Not currently being treated with specific IPF therapy for the reasons: intolerant or not responsive to approved IPF therapies; ineligible to receive approved IPF therapies; declines approved IPF therapies

Exclusion Criteria:

1. Any of the following cardiovascular diseases: uncontrolled, severe hypertension (≥160/100 mmHg), within 6 months of Screening; myocardial infarction within 6 months of Screening; unstable cardiac angina within 6 months of Screening

2. Interstitial lung disease (ILD) associated with known primary diseases (e.g., sarcoidosis, amyloidosis and coronavirus disease 2019 [COVID-19]), connective tissue disorders (e.g., rheumatoid arthritis, systemic lupus erythematosus, Sjogren's, dermatomyositis, scleroderma), exposures (e.g., radiation, silica, asbestos and coal dust) or drugs (e.g., amiodarone)

3. Known active bacterial, viral, fungal, mycobacterial or other infection, including tuberculosis or atypical mycobacterial disease (fungal infections of nail beds are allowed). The subject must be 3 months beyond any acute infection with COVID-19 if there has been a prior infection

4. Clinically significant pulmonary hypertension requiring chronic medical therapy

5. Use of any of the following therapies within 4 weeks prior to Screening, during the Screening Period or planned during the trial: prednisone at steady dose >10 mg/day or equivalent or cyclosporine A. Prednisone ≤10 mg/day (or equivalent dosing of glucocorticoids) is allowed