Tetanus-diphtheria-acellular Pertussis (Tdap)Phase 1/2NCT06997627
A Phase I/II Study to Evaluate the Safety and Immunogenicity of GC3111B in Healthy Adults
A Phase 1/2 study testing GC3111B and Boostrix® in people with Tetanus-diphtheria-acellular Pertussis (Tdap), run by GC Biopharma Corp at 1 site in South Korea.
Trial summary
This clinical trial consists of two parts: Part 1, which explores safety, and Part 2, which examines both safety and efficacy (immunogenicity). Part 1 is a single-center, open-label, single-group study, while Part 2 is designed as a multicenter, double-blind, randomized, active-controlled trial. Read more about this study
- Who is it for?
- Ages 19 to 64 yearsHealthy volunteers can take part
- Conditions the study is for
- Tetanus-diphtheria-acellular Pertussis (Tdap)
- What is being tested?
- GC3111B and Boostrix®
- Type of treatment
- Vaccines, Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 120 participants
- Where
- 1 siteSouth Korea
- Study dates
- 5 Jun 2025to May 2026
- Phase
- Phase 1/2
- Are there results?
- Not yet: the study is under way
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 19 to 64 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Healthy adults aged 19 to 64 years old as of the date of written consent.
- Individuals with no history of vaccination with a vaccine containing diphtheria, tetanus, or pertussis antigens within the past 2 years prior to administration of the investigational product.
Who cannot join
- Individuals who have received a vaccine within 4 weeks prior to administration of the investigational product.
- Individuals with a history of Tdap vaccination prior to administration of the investigational product.
- Pregnant and breastfeeding women.
- Individuals who have participated in other clinical trials involving investigational products/devices within 6 months prior to administration of the investigational product.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Sujin Lee contact
South Korea1 site, 1 recruiting
- Recruiting
The Catholic Univ. of Korea Eunpyeong St. Mary's Hospital
Seoul, 1021
Junghyun Choi, MD, PhD.
About this study
Official title: An Open(Part 1), Single-arm(Part 1), Randomized(Part 2), Double-blind(Part 2), Active-controlled(Part 2) Phase I/II Clinical Trial to Evaluate the Safety and Efficacy (Immunogenicity) of GC3111B in Healthy Adults
This clinical trial consists of two parts: Part 1, which explores safety, and Part 2, which examines both safety and efficacy (immunogenicity). Part 1 is a single-center, open-label, single-group study, while Part 2 is designed as a multicenter, double-blind, randomized, active-controlled trial.
- Being tested
- GC3111B, Boostrix®
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
GC3111BBiological
0.5 mL, Intramuscular injection
Boostrix®Biological
0.5 mL, Intramuscular injection
| Study group | Role | What they receive |
|---|---|---|
| GC3111B | Experimental | Participants randomized to receive a single dose of GC3111B vaccine. Receives: Biological: GC3111B |
| Boostrix® | Active comparator | Participants randomized to receive a single dose of Boostrix® vaccine. Receives: Biological: Boostrix® |
What is being measured
The primary outcome is the main question the study is designed to answer.
Solicited adverse events occurring by day 14 after administration of the investigational product
Measured: 14 days after administration of the IP
Unsolicited adverse events occurring by day 28 after administration of the investigational product
Measured: 28 days after administration of the IP
Acute adverse events occurring within 30 minutes after administration of the investigational product
Measured: 30 minutes after administration of the IP
Serious adverse events (SAE) and adverse events of special interest (AESI) occurring up to 180 days after administration of the investigational product
Measured: 180 days after administration of the IP
Clinically significant findings in vital signs, laboratory tests, 12-lead electrocardiograms, and physical examinations
Measured: 28 days after administration of the IP
Secondary outcomes (3)
Antibody rates for diphtheria and tetanus on day 28 after administration of the investigational product
Measured: 28 days after administration of the IP
Boosting response rates for diphtheria, tetanus, and pertussis on day 28 after administration of the investigational product
Boosting response rate: 1) If less than 0.1 IU/ml before vaccination, it should be 0.4 IU/ml or higher after the vaccination, or 2) if not less than 0.1 IU/ml before vaccination, it should be 4 times or higher after the vaccination.
Measured: 28 days after administration of the IP
Geometric mean concentrations (GMC) of antibodies against diphtheria, tetanus, and pertussis antitoxins (anti-PT, anti-FHA, anti-PRN) on day 28 after administration of the investigational product
Measured: 28 days after administration of the IP
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted30 May 2025
- Study start5 Jun 2025
- Primary completionMay 2026 (estimated)
- Study completionMay 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Tetanus-diphtheria-acellular Pertussis (Tdap)Studies 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
- Parallel groups
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Investigator
- Enrolment
- 120 participants (estimated)
Sponsor and investigators
- Lead sponsor
- GC Biopharma Corp
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06997627
- Sponsor's protocol ID
- GC3111B_Tdap_P1201
- Status last verified
- Jul 2025
- First submitted
- 15 May 2025
- Last updated
- 10 Jul 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 10 Jul 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- An Open(Part 1), Single-arm(Part 1), Randomized(Part 2), Double-blind(Part 2), Active-controlled(Part 2) Phase I/II Clinical Trial to Evaluate the Safety and Efficacy (Immunogenicity) of GC3111B in Healthy Adults
- ClinicalTrials.gov ID
- NCT06997627
- Acronym / sponsor ID
- GC3111B_Tdap_P1201
- Phase
- Phase 1/2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 120 participants (estimated)
- Lead sponsor
- GC Biopharma CorpIndustry (pharma, biotech, devices)
- Study start
- 5 Jun 2025 (actual)
- Primary completion
- May 2026 (estimated)
- Study completion
- May 2026 (estimated)
- First posted
- 30 May 2025 (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 clinical trial consists of two parts: Part 1, which explores safety, and Part 2, which examines both safety and efficacy (immunogenicity). Part 1 is a single-center, open-label, single-group study, while Part 2 is designed as a multicenter, double-blind, randomized, active-controlled trial.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, care provider, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| GC3111B | Experimental | Biological: GC3111BParticipants randomized to receive a single dose of GC3111B vaccine. |
| Boostrix® | Active comparator | Biological: Boostrix®Participants randomized to receive a single dose of Boostrix® vaccine. |
Who may qualify
- Ages
- 19 to 64 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (2 listed)
- Healthy adults aged 19 to 64 years old as of the date of written consent.
- Individuals with no history of vaccination with a vaccine containing diphtheria, tetanus, or pertussis antigens within the past 2 years prior to administration of the investigational product.
Key exclusion criteria (4 listed)
- Individuals who have received a vaccine within 4 weeks prior to administration of the investigational product.
- Individuals with a history of Tdap vaccination prior to administration of the investigational product.
- Pregnant and breastfeeding women.
- Individuals who have participated in other clinical trials involving investigational products/devices within 6 months prior to administration of the investigational product.
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 |
|---|---|---|
| GC3111B0.5 mL, Intramuscular injection | Biological | GC3111B |
| Boostrix®0.5 mL, Intramuscular injection | Biological | Boostrix® |
Primary outcome
Solicited adverse events occurring by day 14 after administration of the investigational product
Time frame: 14 days after administration of the IP
Unsolicited adverse events occurring by day 28 after administration of the investigational product
Time frame: 28 days after administration of the IP
Acute adverse events occurring within 30 minutes after administration of the investigational product
Time frame: 30 minutes after administration of the IP
Serious adverse events (SAE) and adverse events of special interest (AESI) occurring up to 180 days after administration of the investigational product
Time frame: 180 days after administration of the IP
Clinically significant findings in vital signs, laboratory tests, 12-lead electrocardiograms, and physical examinations
Time frame: 28 days after administration of the IP
3 secondary outcomes
Antibody rates for diphtheria and tetanus on day 28 after administration of the investigational product
Time frame: 28 days after administration of the IP
Boosting response rates for diphtheria, tetanus, and pertussis on day 28 after administration of the investigational product
Time frame: 28 days after administration of the IP
Geometric mean concentrations (GMC) of antibodies against diphtheria, tetanus, and pertussis antitoxins (anti-PT, anti-FHA, anti-PRN) on day 28 after administration of the investigational product
Time frame: 28 days after administration of the IP
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 10 Jul 2025.
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Healthy Volunteers
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.
Sujin Lee contact
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1/2 study testing GC3111B and Boostrix® in people with Tetanus-diphtheria-acellular Pertussis (Tdap), run by GC Biopharma Corp at 1 site in South Korea.
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 2 inclusion and 4 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: looking for participants now, as of the sponsor's last update on 10 Jul 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in South Korea. 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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Minji Ko (+82-31-260-9143, minji.ko@gccorp.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Solicited adverse events occurring by day 14 after administration of the investigational product (time frame: 14 days after administration of the IP). The study lists 5 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 10 Jul 2025.