To evaluate the efficacy and safety of TQC2731 injection in patients with moderate to severe chronic obstructive pulmonary disease.

Inclusion Criteria:

• Able and willing to provide written informed consent and comply with the study protocol;
• Participant must be ≥40 to ≤80 years of age at the time of signing informed consent.
• Participants with a physician diagnosis of Chronic Obstructive Pulmonary Disease(COPD) and a history of COPD ≥12 months with medical records or related records at the time of screening;
• Post-bronchodilator FEV1/Forced vital capacity (FVC)<0.70 and post-bronchodilator FEV1 % predicted ≥20% and < 80% during screening.
• Modified Medical Research Council (mMRC) Dyspnea Scale grade≥2 during screening.
• Background triple therapy (ICS+long-acting beta-agonists (LABA)+LAMA) for at least 3 months with a stable dose for at least 1 month prior to randomization; Double therapy allowed if ICS is contraindicated.
• With a history of acute exacerbation of ≥2 moderate or ≥1 severe within the previous 12 months prior to screening. Multiple acute exacerbation events with an interval of less than 14 days are counted as one.

Exclusion Criteria:

• COPD with asthma;
• Subjects with active pulmonary diseases other than COPD assessed by the investigator.
• Moderate to severe Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) occurred within 4 weeks prior to screening or during screening;
• History of lung transplantation;
• Previous use of TQC2731.
• Diagnosis of alpha-1 anti-trypsin deficiency;
• History of lung volume reduction surgery or pneumonectomy within 6 months prior to randomization, or planned lung volume reduction surgery during the study period;
• Positive hepatitis B surface antigen, or hepatitis C virus antibody, or syphilis antibody.
• Diagnosis of immunodeficiency, including but not limited to HIV infection;
• Infection requiring systemic therapy within 2 weeks prior to randomization.
• Starting rehabilitation within 4 weeks prior to randomization, or planned rehabilitation during the study period;
• Treatment with oxygen of more than 12 hours per day.
• Heart failure New York Heart Association (NYHA) class III or IV during the screening period.
• History of malignancy within 5 years prior to screening, excluding cervical carcinoma in situ, ductal carcinoma in situ, etc.
• Pregnancy or breastfeeding.