A Phase II Trial of a Recombinant Human Anti-Rabies Virus Monoclonal Antibody

Primary Objective of the study:

（1）To evaluate the safety, tolerability, and Rabies Virus Neutralizing Activity (RVNA) of different doses of a recombinant human anti-rabies virus monoclonal antibody injection (referred to as the anti-rabies mAb), administered alone or in combination with a human rabies vaccine, compared to human rabies immune globulin, in healthy adult participants aged 18-60.

Secondary Objective of the study:

• To evaluate the pharmacokinetics (PK) of the anti-rabies mAb administered alone or in combination with a human rabies vaccine in healthy adult participants aged 18-60.
• To evaluate the incidence of anti-drug antibodies for the anti-rabies mAb compared to human rabies immune globulin, administered alone or in combination with a human rabies vaccine, in healthy adult participants aged 18-60.
• To provide a basis for dose selection for Phase III clinical studies.

Inclusion criteria

• Healthy individuals aged 18-60 years (inclusive), regardless of gender, capable of providing valid legal identification.
• Participants voluntarily agree to participate in the study and sign an informed consent form.
• Female participants must have no plans for pregnancy or egg donation from 14 days prior to dosing until 6 months after dosing and must voluntarily adopt effective physical contraceptive measures. Male participants must have no plans for pregnancy or sperm donation within 6 months after dosing and must voluntarily adopt effective physical contraceptive measures.
• Female participants must weigh ≥45.0 kg and ≤80.0 kg, and male participants must weigh ≥50.0 kg and ≤80.0 kg. Body mass index (BMI) must be between 18.0 and 26.0 kg/m² (inclusive) (BMI = weight in kg / height in m²).
• Vital signs (reference ranges: systolic blood pressure 90-140 mmHg, diastolic blood pressure 60-90 mmHg, pulse rate 50-100 beats per minute, all inclusive; body temperature assessed by the investigator according to the research center's standards), physical examination, and clinical laboratory and auxiliary tests during the screening period must be normal or judged by the investigator to have no clinical significance if abnormal.

Exclusion criteria

• Known allergy to the investigational product (including excipients or similar drugs), or individuals with a history of severe allergic diseases or considered allergic constitution (e.g., allergies to two or more drugs, foods, or pollen) as judged by the investigator to potentially compromise participant safety.
• Clear history of allergy to essential substances that may be encountered during the trial (e.g., skin disinfectants).
• History of clinically severe diseases within the 6 months (180 days) prior to screening that remain unresolved, or current acute or chronic illnesses that may significantly affect the metabolism or safety evaluation of the investigational product.
• History of autoimmune diseases or chronic hepatitis.
• History of seizures, epilepsy, psychiatric or neurological disorders, or family history of seizures or epilepsy.
• Major surgery within the 3 months (90 days) prior to screening, or surgery that may significantly affect the metabolism or safety evaluation of the investigational product.
• Previous vaccination with human rabies vaccine, or suspected history of rabies exposure (defined as bites, scratches, licks on mucous membranes or broken skin by rabid, suspected rabid, or undetermined rabies status animals, or direct contact of open wounds or mucous membranes with saliva or tissues potentially containing rabies virus), as determined by inquiry.
• Positive screening for anti-rabies virus antibodies during the screening period.
• Vaccination with any vaccine other than the rabies vaccine within the 1 month (30 days) prior to screening.
• Use of other antibody-based drugs or immunoglobulins within the 3 months (90 days) prior to screening.
• Use of passive immunizing agents, immunosuppressants, or corticosteroids within the 3 months (90 days) prior to screening.
• Use of medications that may affect the metabolism or safety evaluation of the investigational product within the 14 days prior to screening or ongoing use of such medications.
• Participation in any clinical trial involving the use of investigational drugs or devices within the 3 months (90 days) prior to screening, or planned participation in other clinical trials during this study.
• Regular alcohol consumption within the 3 months (90 days) prior to screening, averaging more than 2 alcohol units per day (1 unit = 17.7 mL ethanol, equivalent to 357 mL of 5% beer, 43 mL of 40% spirits, or 147 mL of 12% wine), or inability to abstain from alcohol during the trial period.
• Smoking habit within the 3 months (90 days) prior to screening (more than 5 cigarettes or equivalent tobacco per day), or inability to abstain from smoking during the trial period.
• Blood loss/donation exceeding 300 mL (excluding physiological blood loss in females) within the 3 months (90 days) prior to screening, receipt of blood transfusions or blood products, or plans to donate blood within 1 month (30 days) after the trial.
• Inability to avoid strenuous exercise within 14 days after dosing.
• History of drug abuse.
• Pregnant or breastfeeding women.
• History of needle or blood phobia, poor vascular condition, or intolerance to venipuncture.
• Participants who may be unable to cooperate in completing the study for other reasons or are deemed unsuitable for inclusion by the investigator.