Japanese Encephalitis Virus DiseasePhase 1/2NCT06680128
A Study to Assess the Safety, Reactogenicity, and Immunogenicity of SK Japanese Encephalitis Messenger Ribonucleic Acid (mRNA) Vaccines (GBP560) in Healthy Adults
A Phase 1/2 study testing GBP560-A, GBP560-B and IXIARO in people with Japanese Encephalitis Virus Disease, run by SK Bioscience Co., Ltd. at 3 sites in 2 countries.
Trial summary
This is a 2-Stage, Phase I/II Study to Assess the Safety, Reactogenicity, and Immunogenicity of SK Japanese Encephalitis mRNA Vaccines (GBP560) in Healthy Adults (Aged 18 Years and Older) Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Japanese Encephalitis Virus Disease
- What is being tested?
- GBP560-A, GBP560-B and IXIARO
- Type of treatment
- Vaccines, Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 161 participants
- Where
- 3 sitesin 2 countries
- Study dates
- 24 Feb 2025to 31 Jul 2026
- Phase
- Phase 1/2
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- [Age]
- For Stage 1, participant must be 18 to 55 years of age inclusive, at the time of signing the informed consent.
- For Stage 2, participant must be 18 years of age and older, at the time of signing the informed consent.
- [Type of Participant and Disease Characteristics]
- Participants who are healthy as determined by medical evaluation including medical history, vital signs, physical examination, clinical laboratory tests and medical judgement of the investigator.
- Participants who are willing and able to attend all scheduled visits and comply with all study procedures.
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- Body mass index (BMI) within the range of 18.5-29.9 kg/m2 (inclusive) at screening
- [Sex and Contraceptive/Barrier Requirements]
- All participants must agree to be heterosexually inactive or agree to consistently use at least one acceptable method of contraception from at least 4 weeks prior to the 1st study vaccination to 12 weeks after the last study vaccination (Visit 9) (See Appendix 10.4 for detailed contraceptive methods).
- Female participants with a negative urine or serum pregnancy test at screening.
- Female participants who are surgically sterile (e.g., having undergone a full hysterectomy, bilateral salpingectomy, or bilateral oophorectomy) or postmenopausal with amenorrhea for at least 12 months are not subject to a pregnancy test.
- [Informed Consent]
- Participants who are capable of giving signed informed consent as described in Appendix 10.1.3 which includes compliance with the requirements and restrictions listed in the informed consent form (ICF) and in this protocol before initiation of any trial-specific procedures.
Who cannot join
- [Medical Conditions]
- Any clinically significant respiratory symptoms (e.g., cough, sore throat), febrile illness (tympanic temperature >38°C), or acute illness within 24 hours prior to the 1st study vaccination. Prospective participants with these conditions cannot be included until 24 hours after resolution.
- History of congenital, hereditary, acquired immunodeficiency, or autoimmune disease.
- Any positive test results for hepatitis B surface antigen, hepatitis C antibody, or human immunodeficiency virus (HIV) at screening.
- History of bleeding disorder or thrombocytopenia which is contraindicating intramuscular vaccination in the investigator's opinion.
- History of hypersensitivity and severe allergic reaction (e.g., anaphylaxis, Guillain-Barre syndrome) to any vaccines or components of the study intervention.
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- History of myocarditis, pericarditis or myopericarditis (including the screening 12-lead ECG results from Stage 1 participants), as assessed by the investigator, indicating probable or possible myocarditis, pericarditis, or myopericarditis, or demonstrating clinically significant abnormalities that could affect participant safety or the interpretation of study findings.
- History of JEV infection/other flaviviruses infection (e.g., Dengue, West Nile, Zika, St. Louis Encephalitis, Yellow fever).
- History of malignancy within 1 year prior to the 1st study vaccination (with the exception of malignancy with minimal risk of recurrence at the discretion of the investigator).
- Significant unstable chronic or acute illness that, in the opinion of the investigator, might pose a health risk to the participant if enrolled, or could interfere with the protocol-specified activities, or interpretation of study results.
- The AESIs as outlined in Section 8.1.4 should be considered for evaluating the participant
- Any other conditions which, in the opinion of the investigator, might interfere with the evaluation of the study objectives (e.g., alcohol or drug abuse, neurologic or psychiatric conditions).
- Female participants who are pregnant or breastfeeding.
- (Only for Stage 1) Current smoker or a recent smoking history within 12 weeks prior to screening. Occasional smoker who smokes up to 10 cigarettes per month may be allowed to participate at the investigator's discretion.
- [Prior/Concomitant medication]
- Receipt of JEV vaccination/other flaviviruses vaccination in the past.
- Receipt of any vaccine within 4 weeks prior to the 1st study vaccination or planned receipt of any vaccine from enrollment through 4 weeks after the last study vaccination (Visit 8), except for inactivated influenza vaccination, which may be received at least 2 weeks prior to the 1st study vaccination.
- Receipt of immunoglobulins and/or any blood or blood-derived products within 12 weeks prior to the 1st study vaccination.
- Receipt of immunosuppressive therapy, such as any use of anti-cancer chemotherapy or radiation therapy; or systemic corticosteroid therapy (≥10 mg prednisone/day or equivalent) within 12 weeks prior to the 1st study vaccination. The use of inhaled, topical, or nasal glucocorticoid will be permitted.
- [Prior/Concurrent Clinical Study Experience]
- Participation in another clinical study and receipt of study intervention within 4 weeks prior to the 1st study vaccination, or concurrent, planned participation in another clinical study with study intervention during this study period.
- [Other Exclusions]
- Investigators, or study staff who are directly involved in the conduct of this study or supervised by the investigator, and their respective family members.
- Donation of ≥ 450mL (milliliter) of blood product within 4 weeks prior to screening, or planned donation of blood product from enrollment through 12 weeks after the last study vaccination (Visit 9).
Trial locations and contacts
3 sites in 2 countries.
3 sites in 2 countries
Australia2 sites
Nucleus Network - Brisbane (Q Pharm)
Brisbane
Nucleus Network - Melbourne
Melbourne
New Zealand1 site
New Zealand Clinical Research
Christchurch, Central City, 8011
About this study
Official title: A 2-Stage, Phase I/II, Active-controlled, Randomized, Observer-blinded, Dose-finding Study to Assess the Safety, Reactogenicity, and Immunogenicity of SK Japanese Encephalitis mRNA Vaccines (GBP560) in Healthy Adults (Aged 18 Years and Older)
This is a 2-Stage, Phase I/II Study to Assess the Safety, Reactogenicity, and Immunogenicity of SK Japanese Encephalitis mRNA Vaccines (GBP560) in Healthy Adults (Aged 18 Years and Older)
Read the detailed description
The purpose of this study is to assess the safety, reactogenicity and immunogenicity of SK Japanese Encephalitis mRNA vaccines (GBP560) in healthy adults.
- Conditions
- Japanese Encephalitis Virus Disease
- Being tested
- GBP560-A, GBP560-B, IXIARO, IMOJEV, Normal Saline (Placebo)
- Medical subject headings
- Encephalitis, Japanese
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
GBP560-ABiological
injection volume of 0.5mililiter (mL) with each dose on V2(1day) and V5 (29day) in stage1 and stage2.
Low dose: 3μg Mid dose: 15μg High dose: 50μg
GBP560-BBiological
injection volume of 0.5mL with each dose on V2(1day) and V5 (29day) in stage1 and stage2.
Low dose: 3μg Mid dose: 15μg High dose: 50μg
IXIAROBiological
injection volume of 0.5mL on V2(1day) and V5 (29day) in stage1 and stage2
IMOJEVBiological
injection volume of 0.5mL on V5 (29day) in stage1 and stage2
Normal Saline (Placebo)Biological
injection volume of 0.5mL on V2 (1day) in stage1 and stage2 (This is for IMOJEV placebo)
| Study group | Role | What they receive |
|---|---|---|
| Test group 1-1 (GBP560-A) | Experimental | Low dose level(3µg) for GBP560-A in stage 1. Participants will receive 2 doses of one of the test vaccines at 4-week intervals, respectively. Receives: Biological: GBP560-A |
| Test group 1-2 (GBP560-B) | Experimental | Low dose level (3µg) for GBP560-B in stage 1. Participants will receive 2 doses of one of the test vaccines at 4-week intervals, respectively. Receives: Biological: GBP560-B |
| Test group1-3 (GBP560-A) | Experimental | Mid dose level (15µg) for GBP560-A in stage 1. Participants will receive 2 doses of one of the test vaccines at 4-week intervals, respectively. Receives: Biological: GBP560-A |
| Test group1-4 (GBP560-B) | Experimental | Mid dose level (15µg) for GBP560-B in stage 1. Participants will receive 2 doses of one of the test vaccines at 4-week intervals, respectively. Receives: Biological: GBP560-B |
| Test group1-5 (GBP560-A) | Experimental | High dose level (50µg) for GBP560-A in stage 1. Participants will receive 2 doses of one of the test vaccines at 4-week intervals, respectively. Receives: Biological: GBP560-A |
| Test group1-6 (GBP560-B) | Experimental | High dose level (50µg) for GBP560-B in stage 1. Participants will receive 2 doses of one of the test vaccines at 4-week intervals, respectively. Receives: Biological: GBP560-B |
| Control group1 (IXIARO®) | Active comparator | Participants will receive 2 doses of one of the active comparators (IXIARO®, 6 Antigen Unit, corresponding to a potency of ≤ 460 ng ED) at 4-week intervals, respectively in Stage 1 and Stage 2. Receives: Biological: IXIARO |
| Control group2 (IMOJEV®) | Active comparator | Participants will receive 1 dose of placebo saline and 1 dose of another active comparator (IMOJEV®, 4.0 - 5.8 log PFU) at 4-week intervals, respectively in Stage 1 and Stage 2. Receives: Biological: IMOJEV; Biological: Normal Saline (Placebo) |
| Test group 2-1 (GBP560-A or B) | Experimental | Participants will receive 2 intramuscular injections of the test vaccines in stage 2.
1st will be on Visit 2 and 2nd will be on Visit 5, in line with the selected dose regimen in stage 1. Receives: Biological: GBP560-A; Biological: GBP560-B |
| Test group 2-2 (GBP560-A or B) | Experimental | Participants will receive 2 intramuscular injections of the test vaccines in stage 2.
1st will be on Visit 2 and 2nd will be on Visit 5, in line with the selected dose regimen in stage 1. Receives: Biological: GBP560-A; Biological: GBP560-B |
What is being measured
The primary outcome is the main question the study is designed to answer.
Percentage of participants experiencing any immediate reactions
For all cohort
Measured: 30 minutes (2 hours for the sentinel participants in stage 1) post each vaccination
Percentage of participants reporting any solicited local Adverse Event (AE)
For all cohort
Measured: during the 7 days following each study vaccination
Percentage of participants reporting any solicited systemic Adverse Event (AE)
For all cohort
Measured: during the 7 days following each study vaccination
Percentage of participants experiencing any unsolicited Adverse Event (AE)
For all cohort
Measured: during the 28 days following each study vaccination
Percentage of participants with any Medically Attended Adverse Event (MAAE)
For all cohort
Measured: until 6 months following the last study vaccination
Percentage of participants experiencing any Adverse Event of Special Interest (AESI)s, AEs leading to study withdrawal and Serious Adverse Event (SAE)s during the entire study period
For all cohort
Measured: up to 12 months for stage 1 and up to 24 months for stage 2
Seroprotection rate for both the respective and cross Japanese encephalitis virus (JEV) strains of each vaccine (SA14-14-2 and Beijing-1 strain) in live-virus neutralizing antibody titers at each time point
For stage 2
Measured: At baseline, 2 weeks, 4 weeks following the 1st study vaccination, and at 2 weeks, 4 weeks, 3 months, 6 months, 12 months, and 24 months following the 2nd study vaccination.
Seroresponse rate for both the respective and cross JEV strains of each vaccine (SA14-14-2 and Beijing-1 strain) in live-virus neutralizing antibody titers, from baseline to each subsequent time point
For Stage 2
Measured: At baseline, 2 weeks, 4 weeks following the 1st study vaccination, and at 2 weeks, 4 weeks, 3 months, 6 months, 12 months, and 24 months following the 2nd study vaccination
Geometric Mean Titer (GMT) of neutralizing antibody against both the respective and cross JEV strains of each vaccine (SA14-14-2 and Beijing-1 strain) measured by a live-virus neutralization assay (PRNT) at each time point
For stage 2
Measured: At baseline, 2 weeks, 4 weeks following the 1st study vaccination, and at 2 weeks, 4 weeks, 3 months, 6 months, 12 months, and 24 months following the 2nd study vaccination.
Geometric mean fold rise of neutralizing antibody against both the respective and cross JEV strains of each vaccine (SA14-14-2,Beijing-1 strain), measured by a live-virus neutralization assay(PRNT), from each pre-vaccination to each subsequent timepoint
For Stage 2
Measured: At baseline, 2 weeks, 4 weeks following the 1st study vaccination, and at 2 weeks, 4 weeks, 3 months, 6 months, 12 months, and 24 months following the 2nd study vaccination
Geometric mean fold reduction of neutralizing antibody against both respective and cross JEV strains of each vaccine (SA-14-14-2,Beijing-1 strain), measured by live-virus neutralization assay (PRNT) from persistence baseline to each subsequent timepoint
For Stage 2
Measured: At baseline, 2 weeks, 4 weeks following the 1st study vaccination, and at 2 weeks, 4 weeks, 3 months, 6 months, 12 months, and 24 months following the 2nd study vaccination.
Secondary outcomes (6)
Seroprotection rate for both the respective and cross JEV strains of each vaccine (SA14-14-2 and Beijing-1 strain) in live-virus neutralizing antibody titers at each time point
For Stage 1
Measured: At baseline, 2 weeks, 4 weeks following the 1st study vaccination, and at 2 weeks, 4 weeks, 3 months, 6 months, and 12 months following the 2nd study vaccination
Seroresponse rate for both the respective and cross JEV strains of each vaccine (SA14-14-2 and Beijing-1 strain) in live-virus neutralizing antibody titers, from baseline to each subsequent time point.
For stage 1
Measured: At baseline, 2 weeks, 4 weeks following the 1st study vaccination, and at 2 weeks, 4 weeks, 3 months, 6 months, and 12 months following the 2nd study vaccination
GMT of neutralizing antibody against both the respective and cross JEV strains of each vaccine (SA14-14-2 and Beijing-1 strain) measured by a live-virus neutralization assay (PRNT) at each time point
For stage 1
Measured: At baseline, 2 weeks, 4 weeks following the 1st study vaccination, and at 2 weeks, 4 weeks, 3 months, 6 months, and 12 months following the 2nd study vaccination
Geometric mean fold rise of neutralizing antibody against both the respective and cross JEV strains of each vaccine (SA14-14-2,Beijing-1 strain), measured by live-virus neutralization assay(PRNT), from each pre-vaccination to each subsequent timepoint
For stage 1
Measured: At baseline, 2 weeks, 4 weeks following the 1st study vaccination, and at 2 weeks, 4 weeks, 3 months, 6 months, and 12 months following the 2nd study vaccination.
Geometric mean fold reduction of neutralizing antibody against both respective and cross JEV strains of each vaccine (SA-14-14-2,Beijing-1 strain),measured by live-virus neutralization assay(PRNT) from persistence baseline to each subsequent timepoint
For Stage1
Measured: At baseline, 2 weeks, 4 weeks following the 1st study vaccination, and at 2 weeks, 4 weeks, 3 months, 6 months, and 12 months following the 2nd study vaccination.
Cell-mediated response for cytokines expressed by Cluster of Differentiation 4+ Cluster of Differentiation 8+ T cells (Interferon-γ, Tumor Necrosis Factor-α, measured by Fluorescence-Activated Cell Sorting-Intracellular Cytokine Staining assay.
For all cohort
Measured: At baseline, 4 weeks following the 1st study vaccination, and at 4 weeks and 6 months following the 2nd study vaccination
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Nov 2024
- Study start24 Feb 2025
- Primary completion31 Jul 2026
- Study completion31 Jul 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Japanese Encephalitis Virus DiseaseStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1/2
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Sequential
- Model description
- Stage 1: sequential, Stage 2 : parallel
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 161 participants (actual)
Sponsor and investigators
- Lead sponsor
- SK Bioscience Co., Ltd.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06680128
- Sponsor's protocol ID
- GBP560_001
- Status last verified
- Sep 2026
- First submitted
- 28 Oct 2024
- Last updated
- 11 Sep 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 11 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A 2-Stage, Phase I/II, Active-controlled, Randomized, Observer-blinded, Dose-finding Study to Assess the Safety, Reactogenicity, and Immunogenicity of SK Japanese Encephalitis mRNA Vaccines (GBP560) in Healthy Adults (Aged 18 Years and Older)
- ClinicalTrials.gov ID
- NCT06680128
- Acronym / sponsor ID
- GBP560_001
- Conditions
- Japanese Encephalitis Virus Disease
- Phase
- Phase 1/2
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 161 participants (actual)
- Lead sponsor
- SK Bioscience Co., Ltd.Industry (pharma, biotech, devices)
- Study start
- 24 Feb 2025 (actual)
- Primary completion
- 31 Jul 2026 (actual)
- Study completion
- 31 Jul 2026 (actual)
- First posted
- 8 Nov 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This is a 2-Stage, Phase I/II Study to Assess the Safety, Reactogenicity, and Immunogenicity of SK Japanese Encephalitis mRNA Vaccines (GBP560) in Healthy Adults (Aged 18 Years and Older)
Detailed description
The purpose of this study is to assess the safety, reactogenicity and immunogenicity of SK Japanese Encephalitis mRNA vaccines (GBP560) in healthy adults.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Sequential
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 10
- Model description
- Stage 1: sequential, Stage 2 : parallel
| Arm | Type | Receives |
|---|---|---|
| Test group 1-1 (GBP560-A) | Experimental | Biological: GBP560-ALow dose level(3µg) for GBP560-A in stage 1. Participants will receive 2 doses of one of the test vaccines at 4-week intervals, respectively. |
| Test group 1-2 (GBP560-B) | Experimental | Biological: GBP560-BLow dose level (3µg) for GBP560-B in stage 1. Participants will receive 2 doses of one of the test vaccines at 4-week intervals, respectively. |
| Test group1-3 (GBP560-A) | Experimental | Biological: GBP560-AMid dose level (15µg) for GBP560-A in stage 1. Participants will receive 2 doses of one of the test vaccines at 4-week intervals, respectively. |
| Test group1-4 (GBP560-B) | Experimental | Biological: GBP560-BMid dose level (15µg) for GBP560-B in stage 1. Participants will receive 2 doses of one of the test vaccines at 4-week intervals, respectively. |
| Test group1-5 (GBP560-A) | Experimental | Biological: GBP560-AHigh dose level (50µg) for GBP560-A in stage 1. Participants will receive 2 doses of one of the test vaccines at 4-week intervals, respectively. |
| Test group1-6 (GBP560-B) | Experimental | Biological: GBP560-BHigh dose level (50µg) for GBP560-B in stage 1. Participants will receive 2 doses of one of the test vaccines at 4-week intervals, respectively. |
| Control group1 (IXIARO®) | Active comparator | Biological: IXIAROParticipants will receive 2 doses of one of the active comparators (IXIARO®, 6 Antigen Unit, corresponding to a potency of ≤ 460 ng ED) at 4-week intervals, respectively in Stage 1 and Stage 2. |
| Control group2 (IMOJEV®) | Active comparator | Biological: IMOJEV, Biological: Normal Saline (Placebo)Participants will receive 1 dose of placebo saline and 1 dose of another active comparator (IMOJEV®, 4.0 - 5.8 log PFU) at 4-week intervals, respectively in Stage 1 and Stage 2. |
| Test group 2-1 (GBP560-A or B) | Experimental | Biological: GBP560-A, Biological: GBP560-BParticipants will receive 2 intramuscular injections of the test vaccines in stage 2. 1st will be on Visit 2 and 2nd will be on Visit 5, in line with the selected dose regimen in stage 1. |
| Test group 2-2 (GBP560-A or B) | Experimental | Biological: GBP560-A, Biological: GBP560-BParticipants will receive 2 intramuscular injections of the test vaccines in stage 2. 1st will be on Visit 2 and 2nd will be on Visit 5, in line with the selected dose regimen in stage 1. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (13 listed)
- [Age]
- For Stage 1, participant must be 18 to 55 years of age inclusive, at the time of signing the informed consent.
- For Stage 2, participant must be 18 years of age and older, at the time of signing the informed consent.
- [Type of Participant and Disease Characteristics]
- Participants who are healthy as determined by medical evaluation including medical history, vital signs, physical examination, clinical laboratory tests and medical judgement of the investigator.
Key exclusion criteria (24 listed)
- [Medical Conditions]
- Any clinically significant respiratory symptoms (e.g., cough, sore throat), febrile illness (tympanic temperature >38°C), or acute illness within 24 hours prior to the 1st study vaccination. Prospective participants with these conditions cannot be included until 24 hours after resolution.
- History of congenital, hereditary, acquired immunodeficiency, or autoimmune disease.
- Any positive test results for hepatitis B surface antigen, hepatitis C antibody, or human immunodeficiency virus (HIV) at screening.
- History of bleeding disorder or thrombocytopenia which is contraindicating intramuscular vaccination in the investigator's opinion.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| GBP560-Ainjection volume of 0.5mililiter (mL) with each dose on V2(1day) and V5 (29day) in stage1 and stage2. Low dose: 3μg Mid dose: 15μg High dose: 50μg | Biological | Test group 1-1 (GBP560-A), Test group 2-1 (GBP560-A or B), Test group 2-2 (GBP560-A or B), Test group1-3 (GBP560-A), Test group1-5 (GBP560-A) |
| GBP560-Binjection volume of 0.5mL with each dose on V2(1day) and V5 (29day) in stage1 and stage2. Low dose: 3μg Mid dose: 15μg High dose: 50μg | Biological | Test group 1-2 (GBP560-B), Test group 2-1 (GBP560-A or B), Test group 2-2 (GBP560-A or B), Test group1-4 (GBP560-B), Test group1-6 (GBP560-B) |
| IXIAROinjection volume of 0.5mL on V2(1day) and V5 (29day) in stage1 and stage2 | Biological | Control group1 (IXIARO®) |
| IMOJEVinjection volume of 0.5mL on V5 (29day) in stage1 and stage2 | Biological | Control group2 (IMOJEV®) |
| Normal Saline (Placebo)injection volume of 0.5mL on V2 (1day) in stage1 and stage2 (This is for IMOJEV placebo) | Biological | Control group2 (IMOJEV®) |
Primary outcome
Percentage of participants experiencing any immediate reactions
Time frame: 30 minutes (2 hours for the sentinel participants in stage 1) post each vaccination
For all cohort
Percentage of participants reporting any solicited local Adverse Event (AE)
Time frame: during the 7 days following each study vaccination
For all cohort
Percentage of participants reporting any solicited systemic Adverse Event (AE)
Time frame: during the 7 days following each study vaccination
For all cohort
Percentage of participants experiencing any unsolicited Adverse Event (AE)
Time frame: during the 28 days following each study vaccination
For all cohort
Percentage of participants with any Medically Attended Adverse Event (MAAE)
Time frame: until 6 months following the last study vaccination
For all cohort
Percentage of participants experiencing any Adverse Event of Special Interest (AESI)s, AEs leading to study withdrawal and Serious Adverse Event (SAE)s during the entire study period
Time frame: up to 12 months for stage 1 and up to 24 months for stage 2
For all cohort
Seroprotection rate for both the respective and cross Japanese encephalitis virus (JEV) strains of each vaccine (SA14-14-2 and Beijing-1 strain) in live-virus neutralizing antibody titers at each time point
Time frame: At baseline, 2 weeks, 4 weeks following the 1st study vaccination, and at 2 weeks, 4 weeks, 3 months, 6 months, 12 months, and 24 months following the 2nd study vaccination.
For stage 2
Seroresponse rate for both the respective and cross JEV strains of each vaccine (SA14-14-2 and Beijing-1 strain) in live-virus neutralizing antibody titers, from baseline to each subsequent time point
Time frame: At baseline, 2 weeks, 4 weeks following the 1st study vaccination, and at 2 weeks, 4 weeks, 3 months, 6 months, 12 months, and 24 months following the 2nd study vaccination
For Stage 2
Geometric Mean Titer (GMT) of neutralizing antibody against both the respective and cross JEV strains of each vaccine (SA14-14-2 and Beijing-1 strain) measured by a live-virus neutralization assay (PRNT) at each time point
Time frame: At baseline, 2 weeks, 4 weeks following the 1st study vaccination, and at 2 weeks, 4 weeks, 3 months, 6 months, 12 months, and 24 months following the 2nd study vaccination.
For stage 2
Geometric mean fold rise of neutralizing antibody against both the respective and cross JEV strains of each vaccine (SA14-14-2,Beijing-1 strain), measured by a live-virus neutralization assay(PRNT), from each pre-vaccination to each subsequent timepoint
Time frame: At baseline, 2 weeks, 4 weeks following the 1st study vaccination, and at 2 weeks, 4 weeks, 3 months, 6 months, 12 months, and 24 months following the 2nd study vaccination
For Stage 2
Geometric mean fold reduction of neutralizing antibody against both respective and cross JEV strains of each vaccine (SA-14-14-2,Beijing-1 strain), measured by live-virus neutralization assay (PRNT) from persistence baseline to each subsequent timepoint
Time frame: At baseline, 2 weeks, 4 weeks following the 1st study vaccination, and at 2 weeks, 4 weeks, 3 months, 6 months, 12 months, and 24 months following the 2nd study vaccination.
For Stage 2
6 secondary outcomes
Seroprotection rate for both the respective and cross JEV strains of each vaccine (SA14-14-2 and Beijing-1 strain) in live-virus neutralizing antibody titers at each time point
Time frame: At baseline, 2 weeks, 4 weeks following the 1st study vaccination, and at 2 weeks, 4 weeks, 3 months, 6 months, and 12 months following the 2nd study vaccination
Seroresponse rate for both the respective and cross JEV strains of each vaccine (SA14-14-2 and Beijing-1 strain) in live-virus neutralizing antibody titers, from baseline to each subsequent time point.
Time frame: At baseline, 2 weeks, 4 weeks following the 1st study vaccination, and at 2 weeks, 4 weeks, 3 months, 6 months, and 12 months following the 2nd study vaccination
GMT of neutralizing antibody against both the respective and cross JEV strains of each vaccine (SA14-14-2 and Beijing-1 strain) measured by a live-virus neutralization assay (PRNT) at each time point
Time frame: At baseline, 2 weeks, 4 weeks following the 1st study vaccination, and at 2 weeks, 4 weeks, 3 months, 6 months, and 12 months following the 2nd study vaccination
Geometric mean fold rise of neutralizing antibody against both the respective and cross JEV strains of each vaccine (SA14-14-2,Beijing-1 strain), measured by live-virus neutralization assay(PRNT), from each pre-vaccination to each subsequent timepoint
Time frame: At baseline, 2 weeks, 4 weeks following the 1st study vaccination, and at 2 weeks, 4 weeks, 3 months, 6 months, and 12 months following the 2nd study vaccination.
Geometric mean fold reduction of neutralizing antibody against both respective and cross JEV strains of each vaccine (SA-14-14-2,Beijing-1 strain),measured by live-virus neutralization assay(PRNT) from persistence baseline to each subsequent timepoint
Time frame: At baseline, 2 weeks, 4 weeks following the 1st study vaccination, and at 2 weeks, 4 weeks, 3 months, 6 months, and 12 months following the 2nd study vaccination.
Cell-mediated response for cytokines expressed by Cluster of Differentiation 4+ Cluster of Differentiation 8+ T cells (Interferon-γ, Tumor Necrosis Factor-α, measured by Fluorescence-Activated Cell Sorting-Intracellular Cytokine Staining assay.
Time frame: At baseline, 4 weeks following the 1st study vaccination, and at 4 weeks and 6 months following the 2nd study vaccination
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Sep 2026.
- Individual participant dataSharing planned: No
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Japanese Encephalitis Vaccine
RecruitingObservational study
Risk Assessment of Community Spread of Multiple Endemic Infectious Diseases in a One Health Perspective
Dengue, Chikungunya
Not yet recruitingObservational study
Diagnostics and Surveillance of Acute Meningo-encephalitis Among Children in Cambodia With a Focus on Japanese Encephalitis Virus
Japanese Encephalitis
Active, not recruitingPhase 4
Monitoring JE Antibody Levels in Healthy Populations and Immunization Strategy in Low-Prevalence Areas
Japanese Encephalitis
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
3 sites in 2 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1/2 study testing GBP560-A, GBP560-B and IXIARO in people with Japanese Encephalitis Virus Disease, run by SK Bioscience Co., Ltd. at 3 sites in 2 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 13 inclusion and 24 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 11 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 3 sites in Australia, New Zealand. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this combined phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Percentage of participants experiencing any immediate reactions (time frame: 30 minutes (2 hours for the sentinel participants in stage 1) post each vaccination). The study lists 11 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 11 Sep 2026.