A Study of Efficacy and Safety of IBI3011 in Subjects With Acute Gouty Arthritis

Subjects are eligible for the study if they meet all of the following Inclusion Criteria:

1. Understand and sign the informed consent form;
2. Aged 18 to 75 years, male or female, male or female;
3. Body Mass Index (BMI) between 18.0 kg/m² and 40.0 kg/m²;
4. Meets the 2015 American College of Rheumatology (ACR) Gout Classification Criteria;
5. Has a history of at least 2 gouty arthritis flares within 1 year prior to study drug administration;
6. With an acute gouty arthritis flare occurring within 4 days before study drug administration;
7. Has contraindications to, intolerance of, or inadequate response to colchicine and/or nonsteroidal anti-inflammatory drugs (NSAIDs);
8. At screening, has a Visual Analogue Score (VAS) pain score of ≥50 mm (on a 0-100 mm scale) in the target joint affected by the acute gout flare
9. Agrees to comply with the protocol-specified urate-lowering therapy (ULT) during the study period;
10. Has no childbearing plans and can use adequate contraceptive measures during the trial period and for 6 months after the last dose of study drug

Subjects meeting any of the following criteria are not eligible to attend this clinical study:

1. Have a history of specific allergies (such as asthma, urticaria, eczema, etc.) or hypersensitivity reactions to previous use of biological agents, or atopic diathesis (e.g., allergies to two or more types of drugs, foods, and pollen);
2. Difficulties in venous blood collection or history of dizziness when encountering blood or needles;
3. Have received an experimental agent within 1 month or 5 times half-life (whichever is longer) prior;
4. Have live or attenuated vaccination in the 3 months prior to randomization or plan to receive that during the this trial;
5. Blood donation or blood loss of more than 400 mL within 8 weeks before the screening;
6. Have a history of severe infection, severe trauma, or major surgical procedures within 6 months before the screening;
7. Have infection requiring systemic therapy within 30 days before randomization or has persistent infection before the screening;
8. Presence of infection requiring systemic drug treatment, hospitalization for infection, or receipt of intravenous antibiotics within 30 days before randomization, or ongoing infection at screening
9. Unable to receive intramuscular injection, such as current anticoagulation therapy, thrombocytopenia, or diseases with a risk of thrombocytopenia, such as aplastic anemia, hypersplenism, or known hemorrhagic diseases like idiopathic thrombocytopenic purpura or hemophilia, or chronic periodontal disease;
10. History of malignancy;
11. Female during pregnancy or lactation;
12. Female (or male) of child-bearing potential has childbearing (or sperm donation) plan or reject to use effective contraceptive methods from the screening period to 6 months after the last dose of the investigational product;
13. Average daily alcohol intake exceeding 2 units within 3 months before screening (i.e., more than 1 bottle [500 mL] of beer, 50 mL of 52% alcohol content baijiu, or half a bottle [350 mL] of wine per day on average), or alcohol consumption within 48 hours before drug administration;
14. Have a history of drug abuse, drug dependence, or a positive result in drug screen within 12 months before the screening;
15. Positive screening test for human immunodeficiency virus (HIV) antibody, hepatitis B surface antigen (HBsAg), hepatitis B core antibody (HBcAb) with HBV DNA, or hepatitis C virus (HCV) antibody;
16. Have a history of prolonged QT interval, or QTc > 450ms for males and > 470ms for females during the screening;
17. Meets any of the following conditions:
18. Confirmed active tuberculosis infection: including but not limited to radiologically confirmed active tuberculosis infection
19. Participants with latent tuberculosis infection or at high risk of tuberculosis infection may be enrolled;
20. Received following drugs or therapy within the specified time before to the drug administration:
21. Glucocorticoids: i. Systematic used ≥10mg prednisone or same dose hormone within 24 hours before administration; ii. Longer-term treated with glucocorticoids; iii. Target joint injected glucocorticoid hormone within14 days before administration; iv. Intramuscular or intravenous injected glucocorticoids within 14 days before administration; b) Used anesthetics (Opiates or tramadol) within 24 hours before administration; c) Used NSAIDS and other analgesics within one half-life before drug administration; d) Used colchicine within 12 hours before administration; e) Applied with ice treatment within 4 hours before administration; f) Used any IL-1 blockers, TNF inhibitors, or other biologics preparation within 30 days or within 5 half-lives before administration (whichever is longer);
22. Secondary gout (e.g., gout induced by chemotherapy, transplant-related gout);
23. Infection/septic arthritis, or other acute inflammation arthritis;
24. Meet any of the following clinical laboratory tests during the screening:
25. Total bilirubin (TBIL) > 1.5 upper limit of normal (ULN);
26. Alanine aminotransferase (ALT) or Aspartate aminotransferase (AST) > 3 ULN;
27. Blood triglycerides >300mg/dL or >3.42mmol/L, or a moderate or greater degree of splenomegaly indicated by splenic ultrasound or physical examination;
28. Estimated Glomerular filtration rate (EDFR) ≤60 ml/min/1.73 m2;
29. Suffering the following diseases, including but not limited to:
30. Refractory hypertension or blood pressure higher than 180/110 mmHg during the screening;
31. Uncontrolled diabetes;
32. History of congestive heart failure;
33. Myocardial Infarction (MI), Angina Pectoris, Percutaneous Coronary Intervention (PCI), Coronary Artery Bypass Graft Surgery (CABG), Intracerebral Hemorrhage (ICH), Cerebral Infarction (CI) within 6 months before the screening;
34. requiring dialysis treatment;
35. Reassessment of VAS pain score in the target joint <50 mm immediately before drug administration;
36. History of neuropsychiatric disorders, or considered unsuitable for participation in this clinical trial by the investigator