A Phase II Study to Evaluate the Efficacy and Safety of SYH2059 Tablets in Adult Patients With Idiopathic Pulmonary Fibrosis

Inclusion Criteria: * 1\. Age ≥ 40 years, regardless of gender; * 2\. The investigator confirms the clinical diagnosis of IPF in participants based on chest HRCT, surgical lung biopsy, or transbronchial lung cryobiopsy (if available) performed during the screening period or within 1 year prior to screening (see Appendix 13.7 for details); * 3\. FVCpp ≥ 45% during the screening period; * 4\. Hemoglobin-corrected DLCOpp ≥ 25% and \< 90% during the screening period; * 5\. Received a single stable-dose antifibrotic therapy for at least 12 weeks prior to screening (concurrent use of nintedanib and pirfenidone is prohibited) and will continue after randomization; or had not received stable antifibrotic therapy, or had discontinued such therapy for at least 8 weeks, with no plan to initiate antifibrotic therapy during the trial; * 6\. Understands the purpose and risks of this study, comprehends and agrees to comply with all study procedures, consents to participate, and provides written informed consent. Exclusion Criteria: * 1\. Interstitial lung disease other than IPF. * 2\. Airway obstruction during screening (FEV₁/FVC \< 0.7), or emphysema greater than pulmonary fibrosis on HRCT. * 3\. Confirmed or suspected acute exacerbation of IPF within 3 months prior to screening. * 4\. Investigator judgment that IPF severity showed sustained improvement during the 12 months prior to screening, based on changes in FVC, DLCO and/or HRCT findings. * 5\. Other clinically significant respira…