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Diphtheria-Tetanus-acellular Pertussis VaccinesPhase 3NCT07596173

A Study on the Immune Response and Safety of a Combined Vaccine Against Diphtheria, Tetanus and Acellular Pertussis (dTpa) in Healthy Japanese Adolescents Aged 11 Years to <13 Years

A Phase 3 study testing dTpa vaccine in people with Diphtheria-Tetanus-acellular Pertussis Vaccines, run by GlaxoSmithKline at 10 sites in Japan.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

The purpose of the study is to assess the immune response, reactogenicity and safety of a booster dose of dTpa vaccine 1 month after vaccination in healthy Japanese participants aged 11 to <13 years. Read more about this study

Who is it for?
Ages 11 to 12 yearsHealthy volunteers can take part
What is being tested?
dTpa vaccine
Type of treatment
Vaccines
Could I receive a placebo?
No, everyone receives an active treatment
How many people
90 participants
Where
10 sitesJapan
Study dates
29 Jun 2026to 4 Sep 2026
Phase
Phase 3
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 11 to 12 years
  • All sexes
  • Healthy volunteers accepted
  • Child

Who may be able to join

  • Participants and/or participants' parent(s)/ Legally acceptable representative(s) [LAR(s)], who, in the opinion of the investigator, can and will comply with the requirements of the protocol.
  • Physical or digital informed assent obtained from the participant prior to performance of any study-specific procedure.
  • Physical or digital informed consent obtained from the parent(s)/LAR(s) of the participant prior to performance of any study-specific procedure.
  • Healthy participants as established by medical history and clinical examination at screening.
  • Male/female participant between and including 11 and <13 years of age at the time of the study intervention administration (Visit 1/Day 1).
  • Previously completed all routine childhood vaccinations to the best knowledge of the participant's parent(s)/LAR(s). Participants with documented previous diphtheria, tetanus and pertussis vaccination (primary series and first booster) as per routine vaccination in Japan prior to study enrolment.
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  • Participants did not receive an additional diphtheria, tetanus with or without pertussis vaccination within 5 years prior to enrolment in the study.
  • Japanese ethnic origin.
  • Participants of non-childbearing potential may be enrolled in the clinical study.
  • Participant of childbearing potential may be enrolled in the study if the participant:
  • has practiced adequate contraception for at least 30 days prior to study intervention administration, and
  • has a negative pregnancy test within 24 hours prior to the study intervention administration, and
  • has agreed to continue adequate contraception during the entire treatment period and for 8 weeks after completion of the study intervention administration series.

Who cannot join

  • Medical conditions
  • History of physician-diagnosed or laboratory-confirmed diphtheria, tetanus or pertussis diseases within the past 5 years.
  • History of encephalopathy after administration of a previous dose of pertussis vaccine that could not be attributed to another identifiable cause, progressive neurologic disorder, uncontrolled epilepsy or progressive encephalopathy: pertussis vaccine should not be administered to individuals with these conditions until a treatment regimen has been established and the condition has stabilized.
  • History of transient thrombocytopenia or neurological complications following an earlier immunization against diphtheria and/or tetanus.
  • History of any reaction or hypersensitivity likely to be exacerbated by any component of the study intervention(s) or having shown signs of hypersensitivity after previous administration of diphtheria, tetanus or pertussis vaccines.
  • Any confirmed or suspected immunosuppressive or immunodeficient condition, based on medical history and physical examination
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  • Acute or unstable chronic conditions clinically significant pulmonary, cardiovascular, hepatic, or renal functional abnormality, as determined by physical examination and/or laboratory screening tests.
  • Any other clinical condition that, in the opinion of the investigator, might pose additional risk to the participant due to participation in the clinical study.
  • Condition that in the judgment of the investigator would make intramuscular injection unsafe.
  • Prior/Concomitant therapy
  • Use of any investigational or non-registered product other than the study intervention(s) during the period beginning 30 days before the dose of study intervention(s), or their planned use during the study period.
  • Administration of immunoglobulins or other blood products or plasma derivatives during the period starting 90 days before the study intervention or planned administration during the study period.
  • Chronic administration of immune-modifying drugs and/or planned use of long-acting immune-modifying treatments at any time up to the end of the study.
  • Up to 6 months prior to the study intervention administration:
  • For corticosteroids, this will mean prednisone equivalent ³0.5 mg/kg/day with maximum of 20 mg/day. Inhaled, intra-articular/intra-bursal and topical steroids are allowed.
  • Up to 6 months prior to study intervention administration: long-acting immune-modifying drugs including among others immunotherapy, monoclonal antibodies, antitumoral medication.
  • Planned administration/administration of a vaccine not foreseen by the study protocol in the period starting 30 days before the dose and ending 30 days after the dose of study intervention(s) administration*, with the exception of inactivated influenza vaccine and SARS-CoV-2 vaccine which can be given at any time during the study conduct.
  • If emergency mass vaccination for an unforeseen public health threat (e.g., a pandemic) is recommended and/or organized by public health authorities outside the routine immunization program, the time period described above can be reduced, provided it is used according to the local governmental recommendations and Sponsor is notified.
  • Planned administration of any prophylactic medication in the absence of any symptom and in anticipation of a reaction to the study intervention administration.
  • Prior/Concurrent clinical study participation
  • Concurrently participating in another clinical study, at any time during the study period, in which the participant has been or will be exposed to an investigational or a non-investigational intervention vaccine/drug/invasive medical device.
  • Other exclusion criteria
  • Pregnant or lactating participant.
  • History of /current chronic alcohol consumption and/or drug abuse, based on investigator's judgment.
  • Any study personnel or their immediate dependents, family, or household members.
  • Child in care.

Trial locations and contacts

10 sites in 1 country.

10 sites in 1 country

Japan10 sites

  • GSK Investigational Site

    Fukuoka, 812-0871

  • GSK Investigational Site

    Hokkaido, 004-0052

  • GSK Investigational Site

    Hokkaido, 006-0814

  • GSK Investigational Site

    Hokkaido, 062-0907

  • GSK Investigational Site

    Kumamoto, 862-0924

  • GSK Investigational Site

    Mie, 511-0865

  • GSK Investigational Site

    Osaka, 554-0014

  • GSK Investigational Site

    Saitama, 337-0042

  • GSK Investigational Site

    Saitama, 360-0812

  • GSK Investigational Site

    Shizuoka, 420-8623

Other trials in Japan

About this study

Official title: A Phase 3, Non-randomized, Single-arm, Open-label Study to Assess the Immunogenicity, Safety and Reactogenicity of Combined Reduced-antigen-content Diphtheria, Tetanus and Acellular Pertussis (dTpa) Vaccine, Administered as a Booster Dose in Healthy Japanese Adolescents Aged 11 Years to <13 Years

The purpose of the study is to assess the immune response, reactogenicity and safety of a booster dose of dTpa vaccine 1 month after vaccination in healthy Japanese participants aged 11 to <13 years.

Being tested
dTpa vaccine
Keywords
Diphtheria tetanus and acellular pertussis (dTpa) vaccine, Adolescent, Immune response, Reactogenicity, Safety

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • dTpa vaccineBiological

    Combined reduced antigen content diphtheria, tetanus and acellular pertussis (dTpa) vaccine administered at Day 1.

Study groups in NCT07596173
Study groupRoleWhat they receive
dTpa GroupExperimentalParticipants aged 11 to less than (<) 13 years receive the dTpa vaccine at Day 1.
Receives: Biological: dTpa vaccine

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Number of seropositive participants for anti-pertussis toxin (anti-PT), anti-filamentous hemagglutinin (FHA) and anti-pertactin (PRN) antibodies

    Seropositivity is defined as antibody concentrations (anti-PT, anti-FHA and anti-PRN) are greater than or equal to the assessed assay cut-offs. The considered cut-off values are: anti-PT: 2.693 International Units per milliliter (IU/mL), anti-FHA: 2.046 IU/mL, anti-PRN: 2.187 IU/mL, as measured by Enzyme-Linked Immunosorbent assay (ELISA).

    Measured: 1 month after vaccination

  2. Number of seroprotected participants for anti-diphteria and anti-tetanus antibodies

    Seroprotection is defined as anti-diphtheria and anti- tetanus antibody concentrations being >=0.1 IU/mL as measured by ELISA.

    Measured: 1 month after vaccination

Secondary outcomes (8)

  1. Number of participants with booster-response to pertussis (PT, FHA and PRN) antigens

    Booster response to PT, FHA and PRN antigens is defined as: for participants with pre-vaccination antibody concentration below the assay cut-off, post-vaccination antibody concentration >=4 times the assay cut-off; for participants with pre-vaccination antibody concentration between the assay cut-off and below 4 times the assay cut-off, post-vaccination antibody concentration >= 4 times the pre-vaccination antibody concentration; for participants with pre-vaccination antibody concentration >=4 times the assay cut-off, post-vaccination antibody concentration >=2 times the pre-vaccination antibody concentration.

    Measured: 1 month after vaccination

  2. Antibody concentration against pertussis (PT, FHA, PRN) antigens

    Measured: At baseline (Day 1) and 1 month after vaccination

  3. Antibody concentration for anti-diphtheria and anti-tetanus antibodies

    Measured: At baseline (Day 1) and 1 month after vaccination

  4. Number of participants with solicited local adverse events (AEs)

    Solicited local AEs are pain, redness (erythema) and swelling at administration site.

    Measured: From Day 1 (day of vaccination) to Day 7 post-vaccination

  5. Number of participants with solicited systemic AEs

    Solicited systemic AEs are fever, headache, myalgia (muscle pain), arthralgia (joint pain), fatigue (tiredness) and gastrointestinal symptoms.

    Measured: From Day 1 (day of vaccination) to Day 7 post-vaccination

  6. Number of participants with unsolicited AEs

    An unsolicited AE is an AE that was either not included in the list of solicited AEs or could be included in the list of solicited AEs but with an onset outside the specified period of follow-up for solicited AEs. Unsolicited AEs include both serious and non-serious AEs.

    Measured: From Day 1 (day of vaccination) to Day 30 post-vaccination

  7. Number of participants with serious AEs (SAEs)

    An SAE is defined as any untoward medical occurrence that, at any dose, results in death, is life threatening, requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent or significant disability/incapacity, is a congenital anomaly/birth defect in the offspring of a study participant, abnormal pregnancy outcomes, is a suspected transmission of any infectious agent via an authorized medicinal product, or other situations as per investigator's judgment.

    Measured: From Day 1 (day of vaccination) to Day 30 post-vaccination

  8. Number of participants with AEs leading to study withdrawal

    Measured: From Day 1 (day of vaccination) to Day 30 post-vaccination

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted19 May 2026
  2. Study start29 Jun 2026
  3. Primary completion4 Sep 2026
  4. Study completion4 Sep 2026

Resources

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 3
Primary purpose
Prevention
Allocation
Non-randomised
Intervention model
Single group
Masking
None (open label)
Enrolment
90 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07596173
Sponsor's protocol ID
308734
Status last verified
Sep 2026
First submitted
13 May 2026
Last updated
9 Sep 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Yes: Study Sponsor will assess requests from qualified researchers for anonymized individual patient-level data and related study documents. Data sharing is subject to certain criteria, conditions, and exceptions. For further information, refer to https://www.gsk-studyregister.com/gsk-patient-level-data-sharing-july2025.pdf

Questions about this trial

What is this clinical trial studying?

A Phase 3 study testing dTpa vaccine in people with Diphtheria-Tetanus-acellular Pertussis Vaccines, run by GlaxoSmithKline at 10 sites in Japan.

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 26 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 9 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 10 sites in Japan. 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 phase mean?

Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.

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?

Number of seropositive participants for anti-pertussis toxin (anti-PT), anti-filamentous hemagglutinin (FHA) and anti-pertactin (PRN) antibodies (time frame: 1 month after vaccination). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07596173.

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 9 Sep 2026.

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