It is a randomized, double-blinded, single-dose, 3-arm parallel, comparative study to evaluate the pharmacokinetics, safety and immunogenicity of BAT1806 Injection vs Actemra® (EU-licensed and US-licensed) in healthy Chinese male subjects. A total of 138 subjects are planned to be included and randomized at a ratio of 1:1:1 to receive single intravenous drip of 4 mg/kg BAT1806 Injection or Actemra® (EU-licensed and US-licensed).

The study has a screening period of 7 days. PK blood samples will be collected from subjects to determine the serum concentration of tocilizumab, thus to evaluate the change and similarity of the pharmacokinetics of the three study drugs.

The investigator will perform safety evaluation for vital signs, physical examinations, injection site reaction, ECG, clinical laboratory tests and adverse events throughout the study. Immunogenicity evaluation (ADA, ADA titration and nAb) will also be evaluated.

Inclusion Criteria:

• Signed the Inform Consent Form and fully understood the trial conduction, procedure and potential adverse reactions before entering the trial;
• Willing and able to follow the visits, treatments specified in this study;
• Subjects (including their partners) who are willing to refrain from pregnancy, sperm donation and take effective contraceptive method in the future 6 months (i.e. 6 months after study medication), see Appendix 4 for specific contraceptive methods;
• Healthy male subjects at age of 18-55 years (inclusive for both);
• BMI between 18-28 kg/m2 (inclusive for both) and body weight between 55-85 kg (inclusive for both);
• Normal physical examinations results or abnormality without clinical significance.

Exclusion Criteria:

• Daily smoking amount of >5 cigarettes within 3 months prior to the trial;
• Any current or history of severe allergic reaction to foods or drugs and History of allergy to tocilizumab or severe allergic or anaphylactic reactions to human, humanized, or murine monoclonal antibodies.
• Having a history of alcoholism (14 units of alcohol per week: 1 unit= 285 mL beer, or 25 mL spirit, or 125 mL wine);
• Having donated blood or loss of massive blood (> 450 mL) within 3 months prior to screening, or planning to donate blood or to receive surgery during the study;
• Prior use of prescription medication, over-the-counter drugs, any vitamin products or herbs within 28 days before screening;
• Having significant changes in diet and exercise habits within 2 weeks before screening or from screening to dose;
• Having any diseases that increase the risk of bleeding, such as hemorrhoids with bleeding symptoms, acute gastritis or gastric and duodenal ulcers;
• Color Doppler echocardiography abnormalities with clinical significance;
• Having clinically significant laboratory abnormalities or other clinically indicated diseases (including but not limited to gastrointestinal, renal, liver, neurological, hematological, endocrine, tumor, lung, immune, mental or cardiovascular diseases);
• Ineligible subjects based on investigator's judgement.

Only one site study