A Safety, Tolerability, and Immunogenicity Study of mRNA-1345 and mRNA-1365 in Participants Aged 5 Months to <24 Months

Moderna

Status and phase: Enrolling; Phase 1

Conditions: Human Metapneumovirus; Respiratory Syncytial Virus

Treatments: Biological: Placebo; Biological: mRNA-1345; Drug: Nimenrix; Biological: mRNA-1365

Study type: Interventional

Funder types: Industry

Identifiers

NCT05743881

mRNA-1365-P101

2022-502022-41 (EudraCT Number)

Details and patient eligibility

About

The purpose of this study is to assess the safety and immunogenicity of mRNA-1365, an mRNA vaccine targeting respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) and mRNA-1345, an mRNA vaccine targeting RSV, in participants aged 5 months to <24 months.

Enrollment: 310 estimated patients

Sex: All

Ages: 5 to 24 months old

Volunteers: No Healthy Volunteers

Inclusion criteria

• The participant is 8 months to <24 months (Part A), 5 months to <8 months (Part B), or 8 months to <12 months (Part C) of age at the time of randomization (Day 1/Baseline visit), who is in good general health, in the opinion of the Investigator, based on review of medical history and screening physical examination.
• In the Investigator's opinion, the parent(s)/ legally authorized representative (LAR)(s) understand and are willing and physically able to comply with protocol-mandated follow up, including all procedures, and provide written informed consent.
• The participant is growing normally for age in the opinion of the site clinician in the months prior to enrollment.
• The participant was born at full-term (≥37 weeks gestation) with a minimum birth weight of 2.5 kilograms (kg).
• For Part C Cohort 7: participant must have received nirsevimab ≥6 months prior to Day 1 Visit.
• For Part C Cohort 8: participant was eligible, according to national guidelines, to receive nirsevimab prior to Day 1 Visit but did not do so.

Exclusion criteria

• Has a known history of symptomatic RSV or hMPV infection (Part A: within 3 months; Part B: and Part C since birth) prior to administration of the first dose of investigational product (IP) or has a known close contact with anyone with laboratory-confirmed RSV or hMPV infection within 14 days prior to administration of the first dose of IP (Part A, B, and C).
• Is acutely ill or febrile 24 hours prior to or at the screening visit. Fever is defined as a body temperature ≥38.0°Celsius/≥100.4°Fahrenheit. Participants who meet this criterion may have visits rescheduled within the relevant study visit windows.
• Has previously been administered an investigational or approved vaccine for prevention of RSV or hMPV infection or if the participant's mother received an investigational or approved vaccine for the prevention of RSV or hMPV infection during pregnancy.
• Has received investigational or approved agents for prophylaxis against RSV or hMPV (for example, monoclonal antibodies) or is intending to receive these during the course of the study. For Part C (Cohort 7 only), use of nirsevimab ≥6 months before Day 1 Visit is allowed.
• Has a known hypersensitivity to a component of the vaccine or its excipients. Hypersensitivity includes, but is not limited to, anaphylaxis or immediate allergic reaction of any severity to a previous dose of an mRNA vaccine or any of its components (including polyethylene glycol or immediate allergic reaction of any severity to polysorbate).
• Has a medical condition that, according to the Investigator's judgment, may pose additional risk as a result of participation, interfere with safety assessments, or interfere with interpretation of results.

Note: Other protocol-defined inclusion/exclusion criteria apply.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Triple Blind

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310 participants in 10 patient groups, including a placebo group

Part A: mRNA-1345, Dose 1 (Age Group: 8 to <24 months)

Experimental group

Description:

Participants will receive mRNA-1345 vaccine by intramuscular (IM) injection on Days 1, 57 and 113.

Treatment:

Biological: mRNA-1345

Part A: mRNA-1365, Dose 1 (Age Group: 8 to <24 months)

Experimental group

Description:

Participants will receive mRNA-1365 vaccine by IM injection on Days 1, 57 and 113.

Treatment:

Biological: mRNA-1365

Part A: Placebo (Age Group: 8 to <24 months)

Placebo Comparator group

Description:

Participants will receive mRNA-1345/ mRNA-1365 vaccine matching placebo by IM injection on Days 1, 57 and 113. In countries where applicable, participants may receive Nimenrix instead of placebo on Day 113.

Treatment:

Drug: Nimenrix

Biological: Placebo

Part B: mRNA-1345, Dose 2 (Age Group: 5 to <8 months)

Experimental group

Description:

Participants will receive mRNA-1345 by IM injection on Days 1, 57 and 113.

Treatment:

Biological: mRNA-1345

Part B: mRNA-1365, Dose 2 (Age Group: 5 to <8 months)

Experimental group

Description:

Participants will receive mRNA-1365 by IM injection on Days 1, 57 and 113.

Treatment:

Biological: mRNA-1365

Part B: mRNA-1345 Dose 1 (Age Group: 5 to <8 months)

Experimental group

Description:

Participants will receive mRNA-1345 by IM injection on Days 1, 57 and 113.

Treatment:

Biological: mRNA-1345

Part B: mRNA-1365 Dose 1 (Age Group: 5 to <8 months)

Experimental group

Description:

Participants will receive mRNA-1365 by IM injection on Days 1, 57 and 113.

Treatment:

Biological: mRNA-1365

Part B: Placebo (Age Group: 5 to <8 months)

Placebo Comparator group

Description:

Participants will receive mRNA-1345/ mRNA-1365 vaccine matching placebo by IM injection on Days 1, 57 and 113. In countries where applicable, participants may receive Nimenrix instead of placebo on Day 113.

Treatment:

Drug: Nimenrix

Biological: Placebo

Part C: mRNA-1345 Dose 1 (Age Group 8 to <12 months exposed to nirsevimab)

Experimental group

Description:

Participants who have been previously exposed to nirsevimab will receive mRNA 1345 by IM on Days 1, 57, and 113.

Treatment:

Biological: mRNA-1345

Part C: mRNA-1345 Dose 1 (Age Group 8 to <12 months not exposed to nirsevimab)

Experimental group

Description:

Participants who have not been previously exposed to nirsevimab will receive mRNA 1345 by IM on Days 1, 57, and 113.

Treatment:

Biological: mRNA-1345