A Phase 1 interventional study of SYN023 and Rabies Vaccine in Rabies Post-exposure Prophylaxis, sponsored by Synermore Biologics (Suzhou) Co., Ltd.. Completed at 1 site in China. Open to participants aged 0 Years to 17 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-01-15.
Sponsored by Synermore Biologics (Suzhou) Co., Ltd. · Phase 1, Interventional, and Treatment
This study is a randomized, double-blind, active-controlled design. The goal is to evaluate the safety, pharmacokinetics and pharmacodynamic of SYN023 in combination with rabies vaccine in healthy participants under 18 years of age.
Participants will:
114 studies on the registry are indexed under Rabies; 15 are open to participants now.
This study's enrollment of 108 is below the median of 201 across 104 interventional studies indexed under Rabies.
Browse Rabies studies →Synermore Biologics (Suzhou) Co., Ltd. is the lead sponsor of 6 studies on the registry; 2 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Vaccines made with a weakened form of the germ, such as measles–mumps–rubella (MMR), chickenpox and yellow fever. They can be risky when the immune system is weakened. Flu injections are not live; the nasal flu spray is.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Autoimmune disease
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Live vaccines
Vaccines made with a weakened form of the germ, such as measles–mumps–rubella (MMR), chickenpox and yellow fever. They can be risky when the immune system is weakened. Flu injections are not live; the nasal flu spray is.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A single intramuscular injection of SYN023 at low dose combined with the Chinese licensed Vero Cell Rabies Vaccine (Essen 5-dose regimen)
Biological: SYN023 · Biological: Rabies Vaccine
A single intramuscular injection of SYN023 at high dose combined with the Chinese licensed Vero Cell Rabies Vaccine (Essen 5-dose regimen)
Biological: SYN023 · Biological: Rabies Vaccine
A single intramuscular injection of Human rabies immunoglobulin (HRIG）combined with the Chinese licensed Vero Cell Rabies Vaccine (Essen 5-dose regimen)
Biological: Rabies Vaccine · Biological: HRIG
SYN023 should be administered intramuscularly at sites distant from the vaccine injection site, either at the gluteus maximus or vastus lateralis muscles. The investigator should determine appropriate injection sites for multiple-point administration based on the participant's age and body weight. It is recommended that not more than 6 mL be administered per single gluteus maximus or vastus lateralis muscle, with not more than 4 mL per single injection site (younger children may require reduced volumes per muscle and per injection site based on individual circumstances); Injection time: Day 0.
Also known as: Zamerovimab and Mazorelvimab Injection
Dosage and administration of Rabies vaccine for human use: 0.5 mL, intramuscular injection in the deltoid muscle; Injection time: Days 0, 3, 7, 14, and 28 (Essen 5-dose regimen).
Also known as: Freeze-dried Rabies Vaccine for Human Use (Vero Cells)
HRIG should be administered intramuscularly at sites distant from the vaccine injection site, either in the gluteus maximus or vastus lateralis muscles. The investigator should determine appropriate injection sites for multiple-point administration based on the participant's age and body weight. It is recommended that not more than 6 mL be administered per single gluteus maximus or vastus lateralis muscle, with not more than 4 mL per single injection site (younger children may require reduced volumes per muscle and per injection site based on individual circumstances); Injection time: Day 0.
Also known as: Human Rabies Immunoglobulin
Incidence of adverse drug reactions (ADRs) and adverse events (AEs)
Time frame: 42 days
Incidence of serious adverse events (SAEs)
Time frame: 126 days
Incidence of adverse reactions and adverse events
Time frame: 30 minutes and 7 days
Rabies Virus Neutralizing Activity (RVNA) of Geometric Mean Concentration (GMC)
Rabies Virus Neutralizing Activity (RVNA) was assessed using Rapid Fluorescent Focus Inhibition Test (RFFIT).
Time frame: Days 3, 7, 14, 42, 98 and 126
Percentage of Participants With Rabies Virus Neutralizing Activity (RVNA) ≥0.5 IU/mL
Rabies Virus Neutralizing Activity (RVNA) was assessed using Rapid Fluorescent Focus Inhibition Test (RFFIT).
Time frame: Days 3, 7, 14, 42, 98 and 126
Area Under the Efficacy Curve for the Geometric Mean Concentration (GMC) of Rabies Virus Neutralizing Activity (RVNA)
Rabies Virus Neutralizing Activity (RVNA) was assessed using Rapid Fluorescent Focus Inhibition Test (RFFIT). Area Under the Efficacy Curve for the GMC of RVNA from Study Day 0 to Day 14 after administration (AUEC0-14)
Time frame: Day 0 to Day 14
Maximum serum concentration (Cmax)
Cmax for SYN023 mAb components CTB011 and CTB012 will be estimated at Day 0 (pre-dose), Day 3, Day 7, Day 14, Day 42, Day 98 and Day 126 post-dose, using non compartmental analysis.
Time frame: 126 days
Time to maximum concentration (Tmax)
Tmax for SYN023 mAb components CTB011 and CTB012 will be estimated at Day 0 (pre-dose), Day 3, Day 7, Day 14, Day 42, Day 98 and Day 126 post-dose, using non compartmental analysis.
Time frame: 126 days
Area under the concentration-time curve (AUC0-t and AUC0-∞)
AUC0-t and AUC0-∞ for SYN023 mAb components CTB011 and CTB012 will be estimated at Day 0 (pre-dose), Day 3, Day 7, Day 14, Day 42, Day 98 and Day 126 post-dose, using non compartmental analysis.
Time frame: 126 days
Terminal half-life (t1/2)
t1/2 for SYN023 mAb components CTB011 and CTB012 will be estimated at Day 0 (pre-dose), Day 3, Day 7, Day 14, Day 42, Day 98 and Day 126 post-dose, using non compartmental analysis.
Time frame: 126 days
Ran from Nov 2024 to primary completion in May 2025, 5 months.
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This study is completed, as verified in Dec 2025. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: SYN023
Synermore Biologics (Suzhou) Co., Ltd.