Phase Ⅰ Clinical Study Protocol of GB223 Monoclonal Antibody Injection

Inclusion Criteria:

1. Understand the study procedures and contents, and voluntarily sign the informedconsent form;

2. Aged from 18 to 65 years at ICF signing (inclusive), males or females;

3. At screening, the male body weight≥50kg, female body weight ≥45kg, the body weight ofmales and females is not more than 75kg (inclusive), body mass index (BMI) is withinthe range between 19 and 24.0 (both inclusive);

4. The following tests are normal, or the abnormalities are not clinically significant atscreening: physical examination, vital sign, laboratory tests, ECG test, chestradiography and CT tests of upper and middle abdomen, PPD test and CT test of oralcavity;

5. The subjects and their partners agree to adopt medically confirmed effectivecontraceptive measures during the entire study period and within 12 months after theadministration of investigational products.

6. The subjects can receive follow-up visits as scheduled, well communicate with theinvestigators and complete the study as required by the study.

Exclusion Criteria:

1. Lactating and pregnant women;

2. Subjects who have pregnancy plan within 12 months;

3. Subjects who currently or previously have osteomyelitis or osteonecrosis of jaws, orsubjects who plan to receive invasive dental surgery or jaw surgery, or subjects whosewounds are not cured after dental or oral surgeries;

4. Subjects who have clear medical history of central nervous system, cardiovascular,renal, hepatic, gastrointestinal, respiratory, metabolic system or subjects with othersignificant diseases; subjects who have medical history of psychiatric disorders;subjects with medical history of hypertension or screening systolic blood pressure ≥ 140mmHg and/or diastolic blood pressure ≥ 90mmHg, which are clinically significant atthe discretion of the investigators; subjects who have medical history of orthostatichypotension;

5. Any of the following is met: allergic constitution; known allergic to the componentsof the investigational product or allergy history to any drug or food or pollen;subjects who have abnormal serum immunoglobulin E (IgE) test;

6. Any of the current symptoms, signs or laboratory test abnormalities indicating thepossible presence of acute or subacute infection (e.g., pyrexia, cough, urgentmicturition, urodynia, abdominal pain, diarrhea, cutaneous infected wound etc.)

7. Subjects who have medical history of drug addiction or drug abuse;

8. Smoking more than 5 cigarettes/day or equivalent tobacco; or subjects who cannot stopsmoking during the study period;

9. Weekly alcohol consumption more than 28 units (1 unit = 285 mL of beer or 25 mL ofspirits or 100 mL of wine); or subjects who have positive breath alcohol test within 24 hours before the use of investigational drug;

10. Subjects who meet any of the following criteria: alanine aminotransferase (ALT) oraspartate aminotransferase (AST) >1.5xULN, serum creatinine (Cr) > 1.0xULN;

11. Abnormal routine blood tests: any of the following is met: white blood cells (WBC)<3.0×109/L or >9.15×109/L, neutrophil count (ANC)<1.5×109/L, platelet count (PLT)<100×109/L, hemoglobin (HGB)<113g/L;

12. Abnormal serum calcium: current hypocalcaemia or hypercalcemia, or albumin-correctedserum calcium level is not within the normal laboratory range.

13. Any of the following is positive: hepatitis B surface antigen (HBsAg), hepatitis Cantibody (HCV-Ab), acquired immunodeficiency syndrome antibody (Anti-HIV) andanti-treponema pallidum antibody (TP-Ab);

14. Subjects with abnormal thyroid and parathyroid function and diseases affecting bonemetabolism such as rheumatoid arthritis and osteomalacia;

15. Subjects with recent fracture (within 6 months);

16. Subjects with positive tumor markers (CEA, AFP, PSA and CA-125);

17. Patients who previously or currently have malignant tumors within 5 years beforescreening (excluding adequately treated and completely cured skin basal cell carcinomaor squamous cell carcinoma, cervical in situ carcinoma);

18. Participated in other clinical studies within 3 months before enrollment, or subjectswho received drugs which are known to injure the major organs within 3 months beforeenrollment;

19. Participated in clinical studies of similar investigational products such as denosumabetc.;

20. Use of drugs which may affect bone metabolism within 4 weeks or 5 half-lives (whichever is longer) before this study and the use of drugs which may affect bonemetabolism during this study period; These drugs include but are not limited to thefollowing drugs: contraceptives containing estrogen, bisphosphonate, fluoride, hormonereplacement therapies (i.e., tibolone, estrogen, estrogenic compounds such asraloxifen), calcitonin, strontium, parathyroid hormone or its derivatives, vitamin Dsupplements (>1000IU/day), glucocorticoids (use of inhaled or local glucocorticoid 2weeks before enrollment), anabolic hormone drugs (e.g., metandienone, nandrolonephenylpropionate, hydroxymetholone, stanozolol, nandrolone decanoate, danazolum),calcitriol and diuretics;

21. Subjects who are considered unsuitable for participating in this study for variousreasons at the discretion of the investigator.