A Phase I/II, Dose-finding Study to Assess the Safety, Reactogenicity, and Immunogenicity of a Broadly Protective Sarbecovirus Vaccine (GBP511) in Healthy Adults.

Trial statusRecruiting
Trial phasePhase 1, Phase 2
Trial typeInterventional
Biological sexAll
Age18+
SponsorSK Bioscience Co., Ltd.

About this trial

The purpose of this research study is to evaluate the safety of and the body's immune response to single and multiple vaccinations in healthy men and women. We want to find out what effects GBP511 has on you and your health. We are doing this study to find out:

If the study drug has any side effects when given as single and multiple vaccinations.

If reactogenicity, an indication that the immune systems is working and is preparing to protect the body against future infection, occurs. This is a normal physical inflammatory response that occurs after vaccination, manifesting as localised reactions that may include pain or redness at the injection site, or systemic symptoms such as headache or fever.

If immunogenicity which is when GBP511 causes your body to make antibodies against the non-harmful viral proteins contained within GBP511, called 'neutralising antibodies (Nab),' occurs. And if GBP511 will cause the specialised cells of the body's immune system to mount a defence against the non-harmful viral proteins contained within GBP511, called 'cell-mediated immunity (CMI)'.

In this study, GBP511 will be administered with and without adjuvant, CAS-1. An adjuvant is an ingredient used in some vaccines that help produce a stronger immune response in the people receiving the vaccine and thus helps the vaccine work better.

This study will recruit approximately 368 participants in total and will be conducted in two stages:

Stage 1 will look at two vaccinations with GBP511 when given with and without the CAS-1 adjuvant; and Stage 2 will look at either one or two vaccinations with two candidate GBP511 vaccines chosen from Stage 1 of the study.

Participants will be required to attend Linear's clinical unit on two separate occasions to receive their two vaccinations. On the first day of dosing (Visit 2/Day 1) and second day of dosing (Visit 5/Day 29), we will be testing a single dose of the study drug in up to 168 healthy volunteers who will be divided into 3 groups. Group 1, Groups 2 and 3 will have 56 people each. These 3 groups will be divided into treatment subgroups, with a total of 6 test subgroups and 3 control subgroups. In all groups, neither you or the study doctor will know what subgroup you are part of, and therefore what treatment (GBP511 or Comirnaty+ placebo) you will receive.

Eligibility criteria

This trial accepts healthy volunteers

Qualifiers

For Stage 1, participant must be 18 to 55 years of age inclusive, at the time of signing the informed consent.

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.

Body mass index (BMI) within the range of 18.5-32.0 kg/m2 (revised) at screening

Disqualifiers

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.

Concurrent or a history of virologically or serologically confirmed SARS-CoV-2 infection, or suspected SARS-CoV-2 infection as determined by the investigator, within 24 weeks prior to the 1st study vaccination.

History of virologically or serologically confirmed SARS-CoV-1, or MERS disease.

History of congenital, hereditary, acquired immunodeficiency, or autoimmune disease.

Trial design

Design model

Sequential

Treatments tested in this trial

  • Test Drug 1-1 (GBP511 low dose)

    Biological/Vaccine

    injection volume of 0.5mililiter (mL) with 2-doses at 4 weeks interval in stage 1 and 1-dose or 2-doses at 4 weeks interval in stage 2. Low dose: 2μg/strain, Mid dose: 6μg/strain, High dose: 18μg/strain

  • Test Drug 1-2 (GBP511 mid dose)

    Biological/Vaccine

    injection volume of 0.5mililiter (mL) with 2-doses at 4 weeks interval in stage 1 and 1-dose or 2-doses at 4 weeks interval in stage 2. Low dose: 2μg/strain, Mid dose: 6μg/strain, High dose: 18μg/strain

  • Test Drug 1-3 (GBP511 high dose)

    Biological/Vaccine

    injection volume of 0.5mililiter (mL) with 2-doses at 4 weeks interval in stage 1 and 1-dose or 2-doses at 4 weeks interval in stage 2. Low dose: 2μg/strain, Mid dose: 6μg/strain, High dose: 18μg/strain

  • Test Drug 2-1 (GBP511 low dose + CAS-1)

    Biological/Vaccine

    injection volume of 0.5mililiter (mL) with 2-doses at 4 weeks interval in stage 1 and 1-dose or 2-doses at 4 weeks interval in stage 2. GBP511 - Low dose: 2μg/strain, Mid dose: 6μg/strain, High dose: 18μg/strain CAS-1 standard adjuvant dose

  • Test Drug 2-2 (GBP511 mid dose + CAS-1)

    Biological/Vaccine

    injection volume of 0.5mililiter (mL) with 2-doses at 4 weeks interval in stage 1 and 1-dose or 2-doses at 4 weeks interval in stage 2. GBP511 - Low dose: 2μg/strain, Mid dose: 6μg/strain, High dose: 18μg/strain CAS-1 standard adjuvant dose

  • Test Drug 2-3 (GBP511 high dose + CAS-1)

    Biological/Vaccine

    injection volume of 0.5mililiter (mL) with 2-doses at 4 weeks interval in stage 1 and 1-dose or 2-doses at 4 weeks interval in stage 2. GBP511 - Low dose: 2μg/strain, Mid dose: 6μg/strain, High dose: 18μg/strain CAS-1 standard adjuvant dose

  • Comparator (Comirnaty)

    Biological/Vaccine

    injection volume of 0.3mililiter (mL) with single-dose at visit 2. 30 mcg of SARS-CoV-2 LP.8.1 spike protein mRNA per 0.3mL

  • Placebo (Normal Saline)

    Biological/Vaccine

    injection volume of 0.5mililiter (mL) with single-dose at visit 5.

  • Test Drug 13 (Stage 2, GBP511-A or B)

    Biological/Vaccine

    Participants will receive 2 intramuscular injections of the test vaccine in stage 2. Injections on Day 1, 29 (Visit 2, 5), in line with the selected dose regimen in stage 1.

  • Test Drug 14 (Stage 2, GBP511-A or B)

    Biological/Vaccine

    Participants will receive 2 intramuscular injections of the test vaccine in stage 2. Injections on Day 1, 29 (Visit 2, 5), in line with the selected dose regimen in stage 1.

Treatment groups

368 Participants
are divided into 9 treatment groups

9

Treatment groups

See each treatment group below.

Group A: Test Group 1-1 (GBP511)Experimental treatment 1 intervention
Group B: Test Group 1-2 (GBP511+CAS-1)Experimental treatment 1 intervention
Group C: Control GroupActive comparator 2 interventions
Group D: Test group 1-3 (GBP511)Experimental treatment 1 intervention
Group E: Test group 1-4 (GBP511+CAS-1)Experimental treatment 1 intervention
Group F: Test Group 1-5 (GBP511)Experimental treatment 1 intervention
Group G: Test Group 1-6 (GBP511+CAS-1)Experimental treatment 1 intervention
Group H: Test Group 2-1 (Stage 2)Experimental treatment 1 intervention
Group I: Test Group 2-2 (Stage 2)Experimental treatment 1 intervention

Trial outcomes

Primary outcomes

1

Percentage of participants experiencing any immediate reactions

For stage 1

Time frame
30 minutes (2 hours for sentinel participants) following each study vaccination
2

Percentage of participants reporting any solicited local AEs

For stage 1

Time frame
during the 7 days following each study vaccination
3

Percentage of participants reporting any solicited systemic AEs

For stage 1

Time frame
during the 7 days following each study vaccination
4

Percentage of participants experiencing any unsolicited AEs

For stage 1

Time frame
during the 28 days following each study vaccination

Secondary outcomes

1

Geometric mean titer (GMT) of neutralizing antibody against each matched strain measured by a pseudo-virus neutralization assay

For stage 1

Time frame
At baseline, 2 weeks, 4 weeks following the 1st study vaccination, and 2 weeks, 4 weeks, 3 months, 6 months, and 12 months following the 2nd study vaccination.
2

Geometric mean ratio (GMR) of neutralizing antibody against each matched strain measured by a pseudo-virus neutralization assay

For stage 1

Time frame
From pre-vaccination to baseline, 2 weeks, 4 weeks following the 1st study vaccination, and 2 weeks, 4 weeks, 3 months, 6 months, and 12 months following the 2nd study vaccination.
3

Percentage of participants with ≥ 2-fold and 4-fold rises against each matched strain in pseudo-virus neutralizing antibody titer

For stage 1

Time frame
At baseline, 2 weeks, 4 weeks following the 1st study vaccination, and 2 weeks, 4 weeks, 3 months, 6 months, and 12 months following the 2nd study vaccination.
4

GMT of RBD-binding IgG antibody against each matched strain measured by ECL assay at each time point.

For stage 1,2

Time frame
At baseline, 2 weeks, 4 weeks following the 1st study vaccination, and 2 weeks, 4 weeks, 3 months, 6 months, and 12 months following the 2nd study vaccination (following the last vaccination for stage 2)

Other outcomes

1

GMT of neutralizing antibody against each strain measured by a pseudo-virus neutralization assay at each time point.

For Stage 1\&2, some of the following endpoints may be evaluated in a subset of participants at all or partial time points.

Time frame
At baseline, 2 weeks, 4 weeks following the 1st study vaccination, and 2 weeks, 4 weeks, 3 months, 6 months, and 12 months following the last study vaccination.
2

GMR of neutralizing antibody against each strain measured by a pseudo-virus neutralization assay, from each pre-vaccination to subsequent time point.

For Stage 1\&2, some of the following endpoints may be evaluated in a subset of participants at all or partial time points.

Time frame
At baseline, 2 weeks, 4 weeks following the 1st study vaccination, and 2 weeks, 4 weeks, 3 months, 6 months, and 12 months following the last study vaccination.
3

Percentage of participants with ≥ 2-fold and 4-fold rises against each strain in pseudo-virus neutralizing antibody titer, from baseline to each subsequent time point.

For stage 1\& 2, Some of the following endpoints may be evaluated in a subset of participants at all or partial time points.

Time frame
At baseline, 2 weeks, 4 weeks following the 1st study vaccination, and 2 weeks, 4 weeks, 3 months, 6 months, and 12 months following the last study vaccination.
4

GMT ratios of neutralizing antibody against each matched and mismatched strain measured by a pseudo-virus neutralization assay

For Stage 2

Time frame
Vaccination date, 2 weeks, 4 weeks, 3 months, 6 months, 12 months following the vaccination date.

Sponsors and contacts

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