A Phase III Clinical Study to Evaluate SYN023's Efficacy and Safety

NCT ID: NCT04644484

Last Updated: 2023-04-21

Study Results

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Basic Information

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Recruitment Status

COMPLETED

Clinical Phase

PHASE3

Total Enrollment

1000 participants

Study Classification

INTERVENTIONAL

Study Start Date

2020-09-23

Study Completion Date

2022-12-16

Brief Summary

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This is a Phase 3, blinded, randomized study of SYN023 compared to a China licensed Human Rabies Immunoglobulin (a Rabies immune globulin from human sources, HRIG) for the prevention of rabies as part of post-exposure prophylaxis (PEP). The trial will enroll the World Health Organization (WHO) Category III rabies exposure subjects. The subject's death and rabies data will be reviewed by Data and safety monitoring board (DSMB) to confirm the safety. Besides, rabies vaccine would be administered after Study Drug in each group.

This trial is proposed to further the licensure of SYN023 to provide an effective PEP alternative available to those exposed persons who need such a product. A placebo-controlled rabies trial is unethical thus HRIG is selected as the control group. Rabies immune globulin from equine and human sources (HRIG) have been evaluated in many trials and HRIG is the standard of care in China.

Detailed Description

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This is a Phase 3, randomized, blinded, and active controlled study of SYN023 compared with a China licensed HRIG for PEP of patients who have been confirmed to have met all inclusion/exclusion criteria for their treatment group.

1000 patients aged 18 and above with the World Health Organization (WHO) Category III rabies exposure should be enrolled as planned and randomly assigned to the experimental group and the control group based on a ratio of 3: 1 through on-site stratification as part of PEP.

All subjects should receive wound infiltration injection of SYN023 or HRIG on Study Day 1 (wound conditions should be described and recorded before injection, including diameter, depth, expansion treatment, etc.), and should also simultaneously receive intramuscular injection of one dose of the freeze-dried rabies vaccine for human use (Vero cells) into the deltoid muscle. In accordance with the Essen Scheme, each subject also needs to receive one dose of the freeze-dried rabies vaccine for human use (Vero cells) on Study Days 4, 8, 15, and 29 respectively.

3.0 mL of venous blood samples should be collected 8 times from each subject prior to administration and on Study Day 4, 8, 15, 43, 99, 183, and 365 post administration of study drug. Relevant information should be collected from the subjects through follow-up visits, such as occurrence of rabies and survival conditions.

RVNA should be assayed through rapid fluorescence focus inhibition test (RFFIT).

Local adverse events related to the SYN023 injection sites and injection sites of the first dose and second dose of rabies vaccine, and systemic adverse events (AE) other than injection sites should be collected within 7 days after administration; local adverse events related to the injection sites of the third dose, fourth dose and fifth dose of rabies vaccine, and systemic adverse events (AE) other than the injection sites should be collected 7 days after administration. In addition, all adverse events occurring within 43 days after administration should be collected, and pregnancy conditions in 6 months after administration and all serious adverse events (SAE) occurring during the study period should be collected.

Conditions

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Rabies Communicable Disease Virus Diseases Rhabdoviridae Infections Mononegavirales Infections RNA Virus Infections

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

In this study, 1000 subjects aged 18 and over who had Grade 3 exposure to rabies virus were intended to be enrolled, and randomly assigned to the experimental group and the control group (3:1). Both groups were immunized according to PEP procedures for rabies.
Primary Study Purpose

PREVENTION

Blinding Strategy

QUADRUPLE

Participants Caregivers Investigators Outcome Assessors
Blinding for drugs were carried out by the randomization statistician and other personnel who will not be involved in the implementation of the clinical trial. Under the guidance of the randomization statistician, blinding operators attach the printed labels with numbers to the outer packages of the study drug/control drug according to the blind codes and seal the packages with sealing stickers.

After the completion of blinding for drugs, the blind codes shall be sealed and kept by the randomization statistician. The entire blinding process must be documented. The personnel responsible for blinding must not participate in other relevant works during this clinical trial, and must not disclose the blind codes to any person participating in this clinical trial.

Study Groups

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Experimental Group: SYN023+Rabies Vaccine

SYN023:

Interventions: are administered by direct injection into the wound or by subcutaneous or intramuscular injection when this is not possible SYN023 is an equal mass mixture of CTB011 and CTB012, two monoclonal antibodies that exhibit a wide spectrum of activity against various wild-type rabies strains in vitro.

Dosage form: 6mg/2mL, liquid; Dosage: 0.3 mg/kg of SYN023; Frequency/duration: at Day 1

Rabies vaccine :

Interventions: should be administered in deltoid muscle Dosage form: \>=2.5 IU, freeze-dried vaccine, reconstitute into 0.5 mL before use Dosage: 0.5 mL after reconstitution Frequency/duration: at Day 1, 4, 8, 15, 29

Group Type EXPERIMENTAL

SYN023

Intervention Type BIOLOGICAL

The finished product of SYN023 is a mixture of 3.0 mg/mL CTB011 and 3.0 mg/mL CTB012 at a ratio of 1:1. SYN023 is a sterile and preservative-free injection, and the excipient contains 25 mM histidine (3.879 mg/mL), 150 mM sodium chloride (8.766 mg/mL) and 0.02% polysorbate 80 (0.2 mg/mL) and pH of 6.0. Each vial contains 2.15 mL of SYN023, or 6.45 mg of monoclonal antibody. The glass bottle was closed with a 13 mm bromobutyl rubber stopper, a 13 mm aluminum crimping cap and a polypropylene flip-open lid.

Rabies Vaccine

Intervention Type BIOLOGICAL

Interventions: The Chinese licensed rabies vaccine should be administered in deltoid muscle Dosage form: \>=2.5 IU, freeze-dried vaccine, reconstitute into 0.5 milliliters (mL) before use Dosage: 0.5 mL after reconstitution Frequency/duration: at Day 1, 4, 8, 15, 29

Control Group: Human Rabies Immune Globulin (HRIG)+Rabies Vaccine

Human Rabies Immune Globulin (HRIG):

Interventions: are administered by direct injection into the wound or by subcutaneous or intramuscular injection when this is not possible Dosage form: 100 IU/mL, liquid; Dosage: 20 IU/kg; Frequency/duration: at Day 1

Rabies vaccine :

Interventions: should be administered in deltoid muscle Dosage form: \>=2.5 IU, freeze-dried vaccine, reconstitute into 0.5 mL before use; Dosage: 0.5 milliliters (mL) after reconstitution; Frequency/duration: at Day 1, 4, 8, 15, 29

Group Type ACTIVE_COMPARATOR

Human Rabies Immune Globulin (HRIG)

Intervention Type BIOLOGICAL

The HRIG is a Chinese licensed Human Rabies Immunoglobulin, which are derived from human plasma, and then purified and filled in the injectable vial form. The HRIG is indicated for the Post-exposure Prophylactic (PEP) of Rabies

Rabies Vaccine

Intervention Type BIOLOGICAL

Interventions: The Chinese licensed rabies vaccine should be administered in deltoid muscle Dosage form: \>=2.5 IU, freeze-dried vaccine, reconstitute into 0.5 milliliters (mL) before use Dosage: 0.5 mL after reconstitution Frequency/duration: at Day 1, 4, 8, 15, 29

Interventions

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SYN023

The finished product of SYN023 is a mixture of 3.0 mg/mL CTB011 and 3.0 mg/mL CTB012 at a ratio of 1:1. SYN023 is a sterile and preservative-free injection, and the excipient contains 25 mM histidine (3.879 mg/mL), 150 mM sodium chloride (8.766 mg/mL) and 0.02% polysorbate 80 (0.2 mg/mL) and pH of 6.0. Each vial contains 2.15 mL of SYN023, or 6.45 mg of monoclonal antibody. The glass bottle was closed with a 13 mm bromobutyl rubber stopper, a 13 mm aluminum crimping cap and a polypropylene flip-open lid.

Intervention Type BIOLOGICAL

Human Rabies Immune Globulin (HRIG)

The HRIG is a Chinese licensed Human Rabies Immunoglobulin, which are derived from human plasma, and then purified and filled in the injectable vial form. The HRIG is indicated for the Post-exposure Prophylactic (PEP) of Rabies

Intervention Type BIOLOGICAL

Rabies Vaccine

Interventions: The Chinese licensed rabies vaccine should be administered in deltoid muscle Dosage form: \>=2.5 IU, freeze-dried vaccine, reconstitute into 0.5 milliliters (mL) before use Dosage: 0.5 mL after reconstitution Frequency/duration: at Day 1, 4, 8, 15, 29

Intervention Type BIOLOGICAL

Other Intervention Names

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A Humanized Anti-Rabies Molecular antibodies cocktails Freeze-dried Rabies Vaccine for Human Use (Vero Cells)

Eligibility Criteria

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Inclusion Criteria

1. Is age ≥18 years, on Study Day 1 with legal identification documents, and plan to live in the local administration area during the study;
2. Category III rabies exposure within 24 hours before Study Drug receipt ;
3. Completed written informed consent process, and signed the informed consent forms;
4. Subjects with the ability to understand the study procedure. And agreed to complete all follow-ups;
5. Female subjects are not in pregnancy (with negative results of urine pregnancy tests before vaccination) and are not in the period of breast feeding, and agree to avoid pregnancy within 121 days after administration;
6. Those who have an armpit temperature ≤ 37.0 °C.

Exclusion Criteria

1. Previous receipt of equine or human (rabies) globulin or rabies vaccination prior to randomization;
2. Clinical evidence of rabies infection;
3. Category I and Category II rabies exposure;
4. Had fever (armpit temperature ≥ 38.5 °C) within 3 days before Study Day 1, or in the acute episode of any chronic diseases;
5. Received immunoglobulin or blood products (except for the anti-tetanus immunoglobulin) within 43 days before Study Day 1, or plan to use any such product (except for the anti-tetanus immunoglobulin) during the study;
6. Received systemic immunosuppressant medication such as systemic corticosteroids but not limited to systemic corticosteroids within 43 days before Study Day 1;
7. History of any immunodeficiency disease (for example: AIDS, systemic lupus erythematosus, etc.); or Laboratory evidence of previous or current immunodeficiency disease, including, but not limited to, any laboratory evidence of HIV infection;
8. History of spleen function deficiency or function injury, such as no spleen caused by any cause (such as splenectomy);
9. History of any severe allergy for vaccination, such as systemic urticaria, allergic laryngeal edema, anaphylactoid purpura, local allergic necrosis (Arthus reaction), angioedema, anaphylactic shock, etc., or allergic to any ingredient of the study drug/vaccine;
10. Previous receipt of any study product (drug, vaccine, biological product or medical device) within 6 months before Study Day 1, or plan to participate in any other clinical study during this study period;
11. History of or clinical evidence of any systemic disease, acute disease or chronic disease (such as convulsions, epilepsy, encephalopathy, nephrotic syndrome, etc.) that the investigator considers to be likely to interfere with safety or efficacy assessment of the study;
12. Previous medical history that may compromise the safety of the subject in the study according to the opinion of the principal investigator.
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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Simoon Record Pharma Information Consulting Co., Ltd.

INDUSTRY

Sponsor Role collaborator

Synermore Biologics (Suzhou) Co., Ltd.

INDUSTRY

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Principal Investigators

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Xiaoqiang Liu, MD, PhD

Role: PRINCIPAL_INVESTIGATOR

Yunnan Province CDC

Locations

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Yunnan Province Center for Disease Control and Prevention (CDC)

Kunming, , China

Site Status

Countries

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China

References

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McClain JB, Chuang A, Reid C, Moore SM, Tsao E. Rabies virus neutralizing activity, pharmacokinetics, and safety of the monoclonal antibody mixture SYN023 in combination with rabies vaccination: Results of a phase 2, randomized, blinded, controlled trial. Vaccine. 2021 Sep 24;39(40):5822-5830. doi: 10.1016/j.vaccine.2021.08.066. Epub 2021 Sep 3.

Reference Type RESULT
PMID: 34483020 (View on PubMed)

Ding Y, Wu M, Zhang H, Zhu X, Hu Y, Li X, Liu J, Tsao E, Liu M, Li C. Safety, pharmacokinetics and pharmacodynamics of SYN023 alone or in combination with a rabies vaccine: An open, parallel, single dose, phase 1 bridging study in healthy Chinese subjects. Antiviral Res. 2020 Dec;184:104956. doi: 10.1016/j.antiviral.2020.104956. Epub 2020 Oct 19.

Reference Type RESULT
PMID: 33091433 (View on PubMed)

Liu X, Zha Y, Wang Z, Jiang Y, Zhang X, Guo J, Li J, Zhang Q, Tsao E. The pharmacokinetics and safety comparison of Zamerovimab and Mazorelvimab monoclonal antibodies vs. HRIG in category III rabies post-exposure prophylaxis: a stratified analysis by wound characteristics. Biologicals. 2025 Aug 13;92:101852. doi: 10.1016/j.biologicals.2025.101852. Online ahead of print.

Reference Type DERIVED
PMID: 40812204 (View on PubMed)

Liu X, Li J, Zha Y, Wang Z, Jiang Y, Zhang X, Guo J, Yu J, Li X, Zhang Q, Reid C, McClain JB, Tsao E. The efficacy and safety of SYN023 (Zamerovimab and Mazorelvimab injection), the recombinant humanized anti-rabies virus monoclonal antibody mixture, combined with rabies vaccine in a WHO category III rabies post-exposure population: A randomized, double-blind, positive control, phase III clinical trial. Vaccine. 2025 Aug 13;61:127289. doi: 10.1016/j.vaccine.2025.127289. Epub 2025 Jun 5.

Reference Type DERIVED
PMID: 40479926 (View on PubMed)

Provided Documents

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Document Type: Study Protocol

View Document

Document Type: Statistical Analysis Plan

View Document

Other Identifiers

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SYN023-006

Identifier Type: -

Identifier Source: org_study_id

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