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

Moderna

Status and phase: Active, not recruiting; 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

2022-502022-41-00 (Other Identifier)

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 at any time since birth, 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 (Part A: within 3 months; Part B and Part C: since birth) or hMPV infection (Part A: within 3 months; Part B: 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 (Parts A, B, and C) or hMPV infection (Parts A or B) within 14 days prior to administration of the first dose of IP.
• 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 (Parts A, B, and C) or hMPV (Parts A and B) infection or if the participant's mother received an investigational or approved vaccine for the prevention of RSV (Parts A, B, and C) or hMPV (Parts A and B) 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