A study to investigate the reactogenicity, safety, and immunogenicity of mRNA-1345 in pregnant women, and safety and immunogenicity in their infants

JRCT ID: jRCT2031230752

Registered date:28/03/2024

Basic Information

• Recruitment status: Pending
• Health condition(s) or Problem(s) studied: Respiratory Syncytial Virus
• Date of first enrollment: 12/04/2024
• Target sample size: 35
• Countries of recruitment: Argentina,Japan,Canada,Japan,Chile,Japan,Denmark,Japan,Panama,Japan,South Africa,Japan,United Kingdom,Japan,United States,Japan
• Study type: Interventional

Intervention(s)

Experimental: mRNA-1345 Dose A
Participants will be vaccinated in the period from 28 weeks to 36 weeks of gestation with a single intramuscular (IM) injection of mRNA-1345 Dose A.
Experimental: mRNA-1345 Dose B
Participants will be vaccinated in the period from 28 weeks to 36 weeks of gestation with a single IM injection of mRNA-1345 Dose B.
Experimental: mRNA-1345 Dose C
Participants will be vaccinated in the period from 28 weeks to 36 weeks of gestation with a single IM injection of mRNA-1345 Dose C.
Placebo Comparator: Placebo
Participants will receive single IM injection of mRNA-1345 vaccine matching placebo in the period from 28 weeks to 36 weeks of gestation.

Outcome(s)

Primary Outcome

- Number of Maternal Participants with Solicited Local and Systemic Adverse Reactions (ARs) [Time Frame: Up to Day 7 (7 days post vaccination)]
- Number of Maternal Participants with Unsolicited Adverse Events (AEs) [Time Frame: Up to Day 28 (28 days post vaccination)]
- Number of Maternal Participants with Medically-Attended AEs (MAAEs) [Time Frame: Day 1 to Month 6 (6 months postdelivery)]
- Number of Maternal Participants with Adverse Events of Special Interest (AESIs) [Time Frame: Day 1 to Month 12 (12 months postdelivery)]
- Number of Maternal Participants with Serious Adverse Events (SAEs) [Time Frame: Day 1 to Month 12 (12 months postdelivery)]
- Number of Maternal Participants with AEs Leading to Discontinuation [Time Frame: Day 1 to Month 12 (12 months postdelivery)]
- Number of Maternal Participants With Pregnancy Outcomes [Time Frame: Day 1 to Month 12 (12 months postdelivery)]
Pregnancy outcomes will include stillbirth, live birth, vaginal delivery, and cesarean section delivery.
- Number of Infant Participants with MAAEs [Time Frame: Day 1 (birth) to Month 12]
- Number of Infant Participants with AESIs [Time Frame: Day 1 (birth) to Month 12]
- Number of Infant Participants with SAEs [Time Frame: Day 1 (birth) to Month 12]
- Number of Infant Participants With Birth Outcomes [Time Frame: Day 1 (birth) to Month 12]
Birth outcomes will include gestational age and anthropometric measurements.

Secondary Outcome

- Geometric Mean Titer (GMT) of Serum RSV-A and RSV-B Neutralizing Antibodies in Maternal Participants [Time Frame: Day 1, Day 29, delivery, and Month 6 (6 months postdelivery)]
- Geometric Mean Concentration (GMC) of Serum RSV-F Binding Antibodies in Maternal Participants [Time Frame: Day 1, Day 29, delivery, and Month 6 (6 months postdelivery)]
- Geometric Mean Fold-Rise (GMFR) of Postbaseline/Baseline Neutralizing Antibody Titers and Binding Antibody Concentrations in Maternal Participants [Time Frame: Day 29, delivery, and Month 6 (6 months postdelivery)]
- Percentage of Maternal Participants With >=4-fold Increase From Baseline in Neutralizing Antibody Titers and Binding Antibody Concentrations [Time Frame: Baseline up to Month 6 (6 months postdelivery)]
- GMT of Serum RSV-A and RSV-B Neutralizing Antibodies in Infant Participants [Time Frame: Day 1 (birth), and Months 2, 6, and 12]
- GMC of Serum RSV-F Binding Antibodies in Infant Participants [Time Frame: Day 1 (birth), and Months 2, 6, and 12]

Key inclusion & exclusion criteria

• Age minimum: >= 18age old
• Age maximum: < 40age old
• Gender: Both

Include criteria

Maternal Participants
- Are adults >=18 years to <40 years of age inclusive, at the time of signing the informed consent.
- Will be 28 to 36 weeks pregnant at the time of vaccination (confirmed by an obstetric ultrasound report).
- Intend to deliver at a maternity unit where study procedures can be performed.
- Are willing and able to attend all study visits, to undergo all study procedures/or have their infant undergo all study procedures, and to comply with study requirements, including a means of communication (for example, phone, text message or email) with study site staff.
- Have received local standard of antenatal care prior to enrollment and expect to continue to do so through the remainder of their pregnancy.
- Have had an antenatal obstetric ultrasound at >=18 weeks of pregnancy or be willing to have an antenatal obstetric ultrasound at Screening if not already conducted.

Infant Participants
- Have consent from infant participant's parent(s)/Legally authorized representative (LAR) if required by local regulations.

Other inclusion criteria may apply.

Exclude criteria

Maternal Participants
- Acutely ill or febrile (temperature >=38.0 degree Celsius [100.4 degree Fahrenheit]) within 72 hours prior to or at the Screening Visit or Day 1.
- Reported history of anaphylaxis or severe hypersensitivity reaction after receipt of any mRNA vaccine or any components of an mRNA-1345 vaccine.
- Any medical, psychiatric, or occupational condition, including reported history of drug or alcohol abuse, that, in the opinion of the Investigator, might pose additional risk due to participation in the study or could interfere with the interpretation of study results.
- Have conditions in the current pregnancy or in previous pregnancies that may affect participant safety, assessment of safety endpoints, assessment of immune response, or adherence to study procedures,
- Received or plans to receive any mRNA vaccine or COVID-19 vaccine within 4 weeks before or after Day 1 and/or any other nonstudy vaccine within 2 weeks before or after Day 1.
- Previous vaccination with any licensed or investigational respiratory syncytial virus RSV vaccine or planned receipt during study participation.

Infant Participants
- Is a child who has been placed under the control or protection of an agency, organization, institution, or entity by the courts, the government, or a government body acting in accordance with powers conferred on them by laws and regulation (for example, foster care). This does not include a child who is adopted or has an appointed LAR.

Other exclusion criteria may apply.

Related Information

• Primary Sponsor: Oduyebo-Omotosho Titi
• Secondary ID(s): NCT06143046,2023-505359-37-00