New combo aims to slow lung scarring in IPF patients

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: 1. Age ≥40 years old, regardless of gender; 2. According to "2022 ATS/ERS/JRS/ALAT Guidelines", it was diagnosed as idiopathic pulmonary fibrosis (IPF); 3. Lung function meets the following conditions during screening: forced vital capacity (FVC) ≥45% predicted value; The dispersion of carbon monoxide (DLco, corrected Hb) in a single breath is between 30% and 80% of the predicted value. 4. HRCT images completed within 12 months before screening can be used to determine UIP mode; 5. It is expected to complete the whole research plan, including 12 weeks of treatment and 1 week of follow-up; 6. Willing to follow all the requirements of drug use, visit and data collection during the study period; 7. Be able to understand the research content and sign the written informed consent; 8. Women of childbearing age provide negative pregnancy test results, and agree to take effective contraceptive measures during the study period and within 3 months after the last administration; Male subjects with fertility also need to take effective contraception at the same time. Exclusion Criteria: 1. Suffering from other interstitial lung diseases caused by non-IPF reasons (such as connective tissue disease-related ILD, chronic allergic pneumonia, pneumoconiosis, drug-induced pneumonia, radiation lung disease, etc.); 2. One or more Acute Exacerbation)； of IPF occurred within 3 months before screening; 3. Have received a lung transplant; 4. Complicated with severe COPD(GOLD III and above), severe asthma or other airway diseases that may interfere with FVC determination; 5. The following systemic immunosuppressive treatments were used within 4 weeks before screening: \> 15 mg/d prednisone (or equivalent dose), cyclophosphamide, methotrexate, tuzumab, rituximab, mycophenolate mofetil, etc. 6. Currently or in the past, allergic to Nidanib, dextromethorphan or any of its auxiliary ingredients; 7. The following laboratory abnormalities exist: ALT or AST \>3×ULN；; eGFR \<30 mL/min/1.73m²； 8. Have a history of uncontrolled mental illness, epilepsy, central nervous system dysfunction, or may induce adverse reactions after using dextromethorphan; 9. Being receiving drugs that may have serious drug interaction with dextromethorphan, such as monoamine oxidase inhibitor (MAOI) and selective serotonin reuptake inhibitor (SSRI), and unable to stop taking drugs; 10. Pregnant or lactating women; 11. At the time of screening, there are other major diseases or medical conditions that researchers think will significantly increase the risk and affect the treatment compliance or data interpretation; 12. Interventional treatment of other clinical trials within 4 weeks before screening. 13. Use Nidanib or pirfenidone for anti-fibrosis treatment within 8 weeks before screening;