Clinical Research Directory

Key Inclusion Criteria: * Age 40 to 80, inclusive, at the time of screening * IPF diagnosed within 5 years prior to screening，and whose HRCT during the screening period meets the diagnostic guidelines for idiopathic pulmonary fibrosis jointly released by the American Thoracic Society (ATS), European Respiratory Society (ERS), Japanese Respiratory Society (JRS), and Latin American Thoracic Association (ALAT) in 2022 * HRCT diagnosis UIP type/possible UIP type (standard HRCT confirmed by central review in recent 3 months) with or without pathological UIP type/possible UIP type (pathology refers to frozen lung biopsy or surgical/thoracoscopic lung biopsy)； * FVCpp ≥ 45% during screening period and the first day; * The percent of predicted DLCO value (corrected by Hb value) at screening is ≥ 30%; * pre-bronchodilator forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) ≥ 0.7 * Before randomization, pirfenidone or nidanib with stable dose ≥ 8 weeks can continue to maintain treatment with stable dose during the study period; Or at least 8 weeks before randomization, pirfenidone or nidanib was not used； Key Exclusion Criteria: * Acute exacerbation of Idiopathic Pulmonary Fibrosis (IPF) within 3 months prior to screening and/or during the screening period (investigator-determined). * Received experimental treatment for IPF within the first 4 weeks of randomization; * Individuals who have received treatment with Namistat or other PDE4 inhibitors within the first 8 weeks of randomization or plan to receive treatment with Namistat or other Phosphodiesterase-4(PDE4) inhibitors during the study period; * Those who have used prednisone\>15mg/day or equivalent dose within the first 2 weeks of randomization and require maintenance; * Have participated in any clinical trials of investigational drugs within 28 days prior to screening or within 5 half lives of the drug (whichever is longer); * Acute respiratory or systemic bacterial, viral, or fungal infections requiring treatment within 4 weeks prior to Visit 1 and/or during the screening period.