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

Phase 1

Active, not recruiting

• Conditions: Respiratory Syncytial Virus; Human Metapneumovirus
• Interventions: Biological: mRNA-1345; Biological: mRNA-1365; Biological: Placebo; Drug: Nimenrix

• Registration Number: NCT05743881
• Lead Sponsor: ModernaTX, Inc.

Brief Summary

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.

Detailed Description

Not available

Study Timeline

• Study Start: 2023-02-15
• Study First Submitted: 2023-02-15
• Study First Submitted QC: 2023-02-15
• Study First Posted: 2023-02-24
• Status Verified: 2024-11
• Last Update Submitted: 2024-11-27
• Last Update Posted: 2024-12-02
• Primary Completion: 2026-08-31
• Study Completion: 2026-09-30

Recruitment & Eligibility

• Status: ACTIVE_NOT_RECRUITING
• Sex: All
• Target Recruitment: 310

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.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Part A: Placebo (Age Group: 8 to <24 months)	Nimenrix	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.
Part B: Placebo (Age Group: 5 to <8 months)	Nimenrix	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.
Part B: mRNA-1345, Dose 2 (Age Group: 5 to <8 months)	mRNA-1345	Participants will receive mRNA-1345 by IM injection on Days 1, 57 and 113.
Part B: mRNA-1365, Dose 2 (Age Group: 5 to <8 months)	mRNA-1365	Participants will receive mRNA-1365 by IM injection on Days 1, 57 and 113.
Part A: mRNA-1345, Dose 1 (Age Group: 8 to <24 months)	mRNA-1345	Participants will receive mRNA-1345 vaccine by intramuscular (IM) injection on Days 1, 57 and 113.
Part A: Placebo (Age Group: 8 to <24 months)	Placebo	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.
Part A: mRNA-1365, Dose 1 (Age Group: 8 to <24 months)	mRNA-1365	Participants will receive mRNA-1365 vaccine by IM injection on Days 1, 57 and 113.
Part B: mRNA-1345 Dose 1 (Age Group: 5 to <8 months)	mRNA-1345	Participants will receive mRNA-1345 by IM injection on Days 1, 57 and 113.
Part C: mRNA-1345 Dose 1 (Age Group 8 to <12 months exposed to nirsevimab)	mRNA-1345	Participants who have been previously exposed to nirsevimab will receive mRNA 1345 by IM on Days 1, 57, and 113.
Part B: Placebo (Age Group: 5 to <8 months)	Placebo	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.
Part B: mRNA-1365 Dose 1 (Age Group: 5 to <8 months)	mRNA-1365	Participants will receive mRNA-1365 by IM injection on Days 1, 57 and 113.
Part C: mRNA-1345 Dose 1 (Age Group 8 to <12 months not exposed to nirsevimab)	mRNA-1345	Participants who have not been previously exposed to nirsevimab will receive mRNA 1345 by IM on Days 1, 57, and 113.

Primary Outcome Measures

Name	Time	Method
Number of Participants with Medically-Attended Adverse Events (MAAEs)	Day 1 through Day 730
Number of Participants with Unsolicited Adverse Events (AEs)	Up to Day 141 (28 days after each injection)
Number of Participants with Adverse Event of Special Interests (AESIs), Serious Adverse Events (SAEs) and Adverse Events Leading to Discontinuation	Day 1 through Day 730
Number of Participants with Solicited Local and Systemic Adverse Reactions (ARs)	Up to Day 120 (7 days after each injection)

Secondary Outcome Measures

Name	Time	Method
Number of Participants with Respiratory Tract Illness (RTI), Lower Respiratory Tract Illness (LRTI), Severe LRTI, Very Severe LRTI, and Hospitalizations Associated with RSV or hMPV	Day 1 through Day 730
Parts A and B: Geometric Mean Titer (GMT) of Serum RSV and hMPV Neutralizing Antibodies	Baseline up to Month 12
Part C: GMT of Serum RSV Neutralizing Antibodies	Baseline up to Month 12
Parts A and B: Geometric Mean Concentration (GMC) of Serum RSV F- and hMPV F-Binding Antibodies	Baseline up to Month 12
Part C: GMC of Serum RSV F-Binding Antibodies	Baseline up to Month 12
Geometric Mean Fold-Rise (GMFR) Postbaseline/baseline Neutralizing Antibody Titers	Baseline up to Month 12
Number of Participants with Vaccine-specific T-cell Responses Measured by Flow Cytometry	Baseline up to month 12

Trial Locations

Locations (55)

Matrix Clinical Research; 🇺🇸 Los Angeles, California, United States

Los Angeles Children's Hospital; 🇺🇸 Los Angeles, California, United States

Velocity Clinical Research, Denver; 🇺🇸 Englewood, Colorado, United States

Meridian Clinical Research; 🇺🇸 Hastings, Nebraska, United States

University Of Florida Health Science Center; 🇺🇸 Jacksonville, Florida, United States

Accel Research Sites - Nona Pediatric Center; 🇺🇸 Orlando, Florida, United States

Clinical Research Prime; 🇺🇸 Idaho Falls, Idaho, United States

MedPharmics - Platinum - PPDS; 🇺🇸 Lafayette, Louisiana, United States

Umass Memorial Medical Center; 🇺🇸 Worcester, Massachusetts, United States

UMASS Chan Medical School; 🇺🇸 Worcester, Massachusetts, United States

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