A Clinical Study of TQC3721 Inhalation Powder in Patients With Chronic Obstructive Pulmonary Disease

Inclusion Criteria:

• Age: 40-75 years old, male or female;

• During screening, according to the Global Oceanographic Library for Discovery (GOLD)guidelines (2024), patients diagnosed with stable moderate to severe COPDshould have Force Expiratory Volume in 1 second (FEV1)/ forced vital capacity (FVC)<0.7 after inhaling bronchodilators; 40% ≤ FEV1 accounts for ≤ 80% of theexpected value;

• When screening, after inhaling salbutamol aerosol for 4 times, there is a certainreversibility in the airway: the absolute value of FEV1 improves by more than 100ml;

• Being able to adjust the current COPD treatment or for COPD patients with initialtreatment, prescribed bronchodilators, including Long-acting Muscarinic Antagonists (LAMA) and/or Long-acting β2-agonist (LABA) inhaled drugs, can be discontinuedduring the screening period after signing the informed consent form;

• The subject is able to discontinue Short acting Beta agonists (SABA) for at least 6hours and Short acting Anticholinergic Agents (SAMA) for at least 8 hours;

• Smoking history ≥ 10 pack years (pack years: number of packs per day multiplied bysmoking years);

• There is no evidence to suggest active respiratory and/or cardiovascular diseasesother than COPD in clinical practice (such as uncontrolled hypertension);

• No other related lung diseases or history of thoracic surgery;

• The subjects were able to undergo reproducible FEV1 lung function testing accordingto the the American Thoracic Society and the European Respiratory Society (ATS/ERS) 2005 standard during screening;

• Body mass index (BMI) is between 18-30kg/m2;

• Participants must agree to use contraceptive methods (such as birth control pills,condoms, or intrauterine devices) with sexual partners of childbearing age duringthe clinical trial period (screening period to 30 days after the last dose);

• The subject is able to use a dry powder inhaler correctly for inhalation.

• Fully understand this study, voluntarily participate, and have signed the "InformedConsent Form".

Exclusion Criteria:

• History or current clinical instability of heart, respiratory, endocrine, metabolic,renal, liver, gastrointestinal, skin, infection, blood system, nervous system, orneurological/psychiatric disorders/abnormalities;

• The result of the human immunodeficiency virus (HIV) antibody test is positive; Theresult of hepatitis B surface antigen (HBsAg) test is positive (if HBsAg ispositive, Hepatitis B virus deoxyribonucleic acid (HBV-DNA) should be checked ifnecessary, and if HBV-DNA<Lower Limit of Quantification (LLOQ), it does not need tobe excluded); Hepatitis C virus (HCV) antibody positive and confirmed presence ofHCV ribonucleic acid (RNA); Positive for Treponema pallidum antibody (TPPA);

• Have a history of illegal drug abuse in the past;

• Have participated in other clinical trials and received the investigational drugwithin 3 months prior to participating in this trial, or within 5 half lives of theinvestigational drug, whichever is shorter;

• Those who have lost blood or donated more than 400 mL of blood within 2 monthsbefore the experiment;

• Have any clear and severe history of drug or food allergies, especially those whoare allergic to ingredients similar to the investigational drug;

• Drinking history (drinking 14 units of alcohol per week: 1 unit=285 ml of beer; or 25 ml of spirits; or 1 glass of wine);

• History of malignant tumors in any organ system within the past 5 years, regardlessof whether treatment has been received or not, except for local basal cell carcinomaof the skin;

• Lower respiratory tract infection occurred within 6 weeks before screening orrandomization. Upper respiratory tract infections requiring antibiotics within 6weeks prior to screening or randomization;

• Have a history of active tuberculosis, bronchiectasis, asthma or other non-specificlung diseases.

• QT interval corrected using Fridericia's formula (QTcF)/R-wave peak to R-wave peak (RR [s]) interval, male>450ms, female>470ms, or history of long QT syndrome beforescreening or randomization;

• Subjects with a history of drug use in the past 2 years;

• Subjects who are unable to comply with past medication and concomitant medicationrestrictions;

• If there is a history of acute exacerbation of COPD within 3 months before screeningor randomization, hospitalization or additional COPD maintenance treatment isrequired. Over the past three years, the average number of frequent exacerbations ofCOPD with moderate to severe severity has been ≥ 2 per year, or resulting inhospitalization for ≥ 2 acute exacerbations per year;

• Oral non selective beta blockers;

• Any situation that researchers believe may pose safety risks to subjects in thetrial or may interfere with the conduct of this study, or where researchers believethat subjects may not be able to complete this study or may not be able to complywith the requirements of this study (due to management or other reasons).