A Phase 2/3, Randomized, Active-controlled, Observer-blinded, Non-inferiority Study to Evaluate the Safety and Immunogenicity of Booster Immunization with DS-5670a/b (Bivalent: Original Strain/Omicron Strain BA.4-5) in Subjects Aged 5 to 11 Years Who Have Completed Initial Immunization with Comirnaty Intramuscular Injection (Univalent: Original Strain)

JRCT ID: jRCT2031220665

Registered date:28/02/2023

Basic Information

• Recruitment status: Not Recruiting
• Health condition(s) or Problem(s) studied: Prevention of infectious disease by Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)
• Date of first enrollment: 27/05/2023
• Target sample size: 210
• Study type: Interventional
• Intervention(s): A dose of either DS-5670a/b or Comirnaty IM will be intramuscularly administered to the deltoid muscle of the upper arm.

Outcome(s)

• Primary Outcome: GMT of blood neutralizing activity against SARS-CoV-2 (Omicron strain BA.5) and seroresponse rate at 4 weeks after study drug administration

Secondary Outcome

Efficacy
- GMT of blood neutralizing activity against SARS-CoV-2 (original strain) and seroresponse rate at 4 weeks after study drug administration
- Incidence of COVID-19 for 52 weeks after study drug administration

Safety
Solicited adverse events (injection site and systemic), Unsolicited adverse events, Serious adverse events, Laboratory values for 28 days after study drug administration

Key inclusion & exclusion criteria

• Age minimum: >= 5age old
• Age maximum: <= 11age old
• Gender: Both

Include criteria

1) Subjects aged 5 to 11 years at the time of informed consent.
2) Having provided written consent to study participation via the legal representative.
3)Having completed initial immunization with Comirnaty IM in the past, with at least 3 months elapsed since the 2nd dose.
4) Able to comply with the rules of the study, undergo physical examinations and tests that are specified in the protocol, and report symptoms or other issues.

Exclude criteria

1) Having any serious cardiovascular, renal, hepatic, blood, neuropsychiatric, developmental disorder, thrombocytopenia, or coagulopathy.
2) Having a medical history of vaccination-related convulsions or epilepsy.
3) Having a concurrent or medical history of myocarditis or pericarditis.
4) Having tested positive for SARS-CoV-2 infection (based on reverse transcription polymerase chain reaction [RT-PCR], other nucleic acid detection methods, or SARS-CoV-2 antigen test) within 3 months before informed consent, or having been diagnosed with coronavirus disease 2019 (COVID-19) based on a physician's examination.
5) Having been diagnosed with immunodeficiency in the past or having a close relative with congenital immunodeficiency.
6) Having symptoms suspected of SARS-CoV-2 infection (eg, respiratory symptoms, headache, malaise, anosmia, dysgeusia, pharyngeal pain) at the time of informed consent
7) Having tested positive for SARS-CoV-2 antibody test at the time of eligibility evaluation, with symptoms suspected of SARS-CoV-2 infection (eg, respiratory symptoms, headache, malaise, anosmia, dysgeusia, pharyngeal pain) within 3 months before informed consent.

Related Information

• Primary Sponsor: Inoguchi Akihiro
• Source(s) of Monetary Support: Ministry of Health, Labour and Welfare