A Phase 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 12 Years and Older Who Have Completed Initial and Booster Immunization with SARS-CoV-2 Vaccines

JRCT ID: jRCT2071220111

Registered date:28/02/2023

Basic Information

• Recruitment status: Complete
• Health condition(s) or Problem(s) studied: Prevention of infection due to SARS-CoV-2
• Date of first enrollment: 19/05/2023
• Target sample size: 1400
• Study type: Interventional
• Intervention(s): A dose of either DS-5670a/b (60ug), DS-5670a (60ug), DS-5670b (60ug or 30ug), or Comirnaty RTU IMA (30ug) will be intramuscularly administered to the deltoid muscle of the upper arm.

Outcome(s)

Primary Outcome

Main Study:
Geometric mean titer (GMT) of blood neutralizing activity against SARS-CoV-2 (Omicron strain BA.5) and seroresponse rate at 4 weeks after study drug administration
Sub Study A, Sub Study B: Not applicable.

Secondary Outcome

Efficacy
Main Study:
- 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
Sub Study A, Sub Study B: Not applicable.

Safety
Main Study, Sub Study B: Solicited adverse events (injection site and systemic), Unsolicited adverse events, Serious adverse events
Sub Study A: 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: >= 12age old
• Age maximum: Not applicable
• Gender: Both

Include criteria

Main Study:
1) Subjects aged 12 years and older at the time of informed consent.
2) Having provided written consent to study participation (by the subject or via his/her legal representative).
3) Having completed initial immunization with Comirnaty IM and booster immunization with Comirnaty RTU IM or having completed booster immunization with Comirnaty RTU IM after receiving initial and booster immunization with Comirnaty IM in the past, with at least 3 months elapsed since the last booster dose of Comirnaty RTU IM.
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 (reporting by the legal representative is also acceptable).
Sub Study A:
1) Subjects aged 12 years and older at the time of informed consent.
2) Having provided written consent to study participation (by the subject or via his/her legal representative).
3) Having completed initial and booster immunization with Comirnaty IM in the past, with at least 3 months elapsed since the last booster 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 (reporting by the legal representative is also acceptable).
Sub Study B:
1) Subjects aged 12 years and older at the time of informed consent.
2) Having provided written consent to study participation (by the subject or via his/her legal representative).
3) Having completed initial immunization with approved SARS-CoV-2 vaccines (Comirnaty IM or Spikevax IM) and booster immunization with approved SARS-CoV-2 vaccines (Comirnaty IM, Comirnaty RTU IM [bivalent: original strain/Omicron strain BA.1, or bivalent: original strain/Omicron strain BA.4-5], Spikevax IM [univalent: original strain, bivalent: original strain/Omicron strain BA.1, or bivalent: original strain/Omicron strain BA.4-5], or Nuvaxovid IM) or DS-5670a in the past, with at least 3 months elapsed since the last booster 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 (reporting by the legal representative is also acceptable).

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 in the past (in the case of Sub Study B, within 3 months before informed consent) for SARS-CoV-2 infection (based on RT-PCR, other nucleic acid detection methods, or SARS-CoV-2 antigen test), or having been diagnosed with 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.

Related Information

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