Evaluating the Efficacy and Safety of of HSK44459 in People With Idiopathic Pulmonary Fibrosis

Inclusion Criteria: 1\. Diagnosed with Idiopathic Pulmonary Fibrosis (IPF) prior to screening, patients must meet both of the following criteria: 1. IPF based on 2022 ATS/ERS/JRS/ALAT Guideline as confirmed by the investigator based on chest HRCT scan taken before or during screening period and if available surgical lung biopsy. 2. Usual interstitial pneumonia (UIP) or probable UIP HRCT pattern consistent with the clinical diagnosis of IPF, as confirmed by the investigator prior to screening. if indeterminate HRCT finding IPF may be confirmed locally by (historical) biopsy. 2\. Percentage Predicted Forced Vital Capacity (ppFVC) ≥45% at screening period. 3. Diffusion capacity of the lung for carbon monoxide (DLCO) (corrected for haemoglobin \[Hb\]) ≥ 25% of predicted normal at screening period. 4\. Patients have to be either: 1. not on therapy with nintedanib or pirfenidone for at least 8 weeks prior to screening and during the screening period, and not planning to start or restart anti fibrotic therapy. 2. on stable therapy with nintedanib or pirfenidone for at least 8 weeks prior to screening and during the screening period. Exclusion Criteria: 1. Clinically significant airways obstruction (Forced Expiratory Volume in One Second (FEV1)/Forced Vital Capacity (FVC) \< 0.7) at screening. 2. In the opinion of the Investigator, other clinically significant pulmonary abnormalities. 3. Acute IPF exacerbation within 4 months prior to screening and/or during the screening period (investigator-determined). 4. Lower respiratory tract infection requiring antibiotics within 2 weeks prior to screening and/or during the screening period. 5. Major surgery (major according to the investigator's assessment) performed within 3 months prior to screening or planned during the course of the trial. (Being on a transplant list is allowed). 6. History of malignancy within 5 years prior to screening. 7. Any suicidal behavior within 2 years prior to screening (i.e. actual attempts, interrupted attempts, abandoned attempts, or prepared actions or attitudes).