Respiratory Syncytial VirusPhase 2NCT06097299
A Study of mRNA-1345, an mRNA Vaccine Targeting Respiratory Syncytial Virus, in Children 2 to <18 Years of Age at High Risk of Respiratory Syncytial Virus
A Phase 2 study testing mRNA-1345 in people with Respiratory Syncytial Virus, run by ModernaTX, Inc. at 50 sites in 2 countries.
Trial summary
Part A: The purpose is to evaluate the safety, reactogenicity, and immunogenicity of mRNA-1345 in children aged 2 to <5 years (Cohort 1) and in children at high risk of respiratory syncytial virus (RSV) disease 5 to <18 years of age (Cohort 2) to inform the dose level selection for the next phase of development (Phase… Read more about this study
- Who is it for?
- Ages 2 to 17 yearsHealthy volunteers can take part
- Conditions the study is for
- Respiratory Syncytial Virus
- What is being tested?
- mRNA-1345
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 349 participants
- Where
- 50 sitesin 2 countries
- Study dates
- 24 Oct 2023to 27 Jun 2025
- Phase
- Phase 2
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 2 to 17 years
- All sexes
- Healthy volunteers accepted
- Child
Who may be able to join
- Part A Cohort 1:
- 2 to <5 years of age at Day 1.
- Healthy, or with stable chronic conditions increasing the risk of RSV disease, per the clinical judgment of the Investigator.
- Cohort 2:
- 5 to <18 years of age at Day 1.
- Participants with stable chronic conditions increasing the risk of RSV disease.
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- Female participants of child-bearing potential may be enrolled in the study, if the participant: 1) has a negative urine pregnancy test at Screening and on the day of injection (Day 1); 2) has practiced adequate contraception or has abstained from all activities that could lead to pregnancy for 28 days prior to Day 1; 3) has agreed to continue adequate contraception through 90 days following injection; and 4) is not currently breastfeeding.
- Part B: Cohort 1 Re-enrollment
- Participants are eligible to be included in the study only if all of the following criteria apply:
- Enrolled and dosed in Part A of Cohort 1; either reached EoS for Part A or were dosed and subsequently discontinued from study for various reasons. This includes participants who were lost to follow-up, if they can be re-engaged.
- Participant's parent(s)/LAR(s) has provided written informed consent for participation in this study.
Who cannot join
- Acutely ill or febrile (temperature ≥38.0°Celsius [100.4°Fahrenheit]) within 72 hours prior to or at the Screening Visit or Day 1.
- History of a diagnosis or condition that, in the judgment of the Investigator, may affect study assessment or compromise participant safety.
- Has received or plans to receive any licensed or authorized vaccine ≤14 days prior to the study vaccine injection (Day 1) or plans to receive a licensed or authorized vaccine within 14 days after the study vaccine injection.
- Receipt of any prior systemic immunosuppressants. Short courses (<7 days) of oral corticosteroids are allowed if completed at least 3 months prior to enrollment.
- Receipt of RSV monoclonal antibodies within 6 months prior to enrollment in the study.
- Participated in an interventional clinical study within 28 days (6 months for a study assessing a product unlicensed/unauthorized in this age group in country of residence at time of enrollment) prior to the day of enrollment or plans to do so while enrolled in this study.
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- Part B: Cohort 1 Re-enrollment
- 1. Participant is currently enrolled in another interventional clinical study.
- Note: Other protocol-defined inclusion and exclusion criteria may apply.
Trial locations and contacts
50 sites in 2 countries.
50 sites in 2 countries
United States47 sites
Velocity Clinical Research- Albuquerque
Albuquerque, New Mexico, 87107
PI-Coor Clinical Research, LLC
Annandale, Virginia, 22003
Elligo Clinical Research Center
Austin, Texas, 78704
Velocity Clinical Research - Banning
Banning, California, 92220
REX Clinical Trials, LLC
Beaumont, Texas, 77701
Velocity Clinical Research-Binghamton
Binghamton, New York, 13905
Coastal Pediatric Research
Charleston, South Carolina, 29414
Javara Inc (Conroe)
Conroe, Texas, 77384
D&H Doral Research Center, LLC
Doral, Florida, 33122
Alliance for Multispeciality Research, LLC
El Dorado, Kansas, 67042
Javara, Inc.
Fayetteville, Georgia, 30214
ASCADA Research, LLC - Family Medicine
Fullerton, California, 92835
Velocity Clinical Research, Gulfport
Gulfport, Mississippi, 39503
West Houston Clinical Research Service
Houston, Texas, 77055
DM Clinical Research - CyFair
Houston, Texas, 77065
Clinical Research Prime
Idaho Falls, Idaho, 83404
Kissimmee Clinical Research
Kissimmee, Florida, 34741
Velocity Clinical Research - Lafayette
Lafayette, Louisiana, 70508
Accel Clinical
Largo, Florida, 33777
Ark Clinical Research
Long Beach, California, 90815
Velocity Clinical Research-Primary Pediatrics, Macon
Macon, Georgia, 31210
Velocity Clinical Research - Boise
Meridian, Idaho, 83642
Velocity Clinical Research Metairie
Metairie, Louisiana, 70006
Med-Care Research
Miami, Florida, 33125
Clinical Research Institute
Minneapolis, Minnesota, 55402
Accel Research Sites - Nona Pediatric Center
Orlando, Florida, 32829
Velocity Clinical Research-Kansas City
Overland Park, Kansas, 66210
SEC Clinical Research
Pensacola, Florida, 32501
The Children's Hospital of Philadelphia - Pediatrics
Philadelphia, Pennsylvania, 19104-4318
DM Clinical Research - Philadelphia
Philadelphia, Pennsylvania, 19107
Velocity Clinical Research, Phoenix
Phoenix, Arizona, 85006
Village Pediatrics
Plano, Texas, 75024
Velocity Clinical Research - Providence
Providence, Rhode Island, 02886
Clinical Research Partners
Richmond, Virginia, 23226
National Clinical Research, Inc.
Richmond, Virginia, 23294
University of Rochester Medical Center (URMC) - Golisano Children's Hospital (GCH)
Rochester, New York, 14620
Peninsula Research Associates (PRA)
Rolling Hills Estates, California, 90274
CenExel iResearch, LLC
Savannah, Georgia, 31405
Headlands Research - Scottsdale
Scottsdale, Arizona, 85260
Tribe Clinical Research
Simpsonville, South Carolina, 29680
Senders Pediatrics
South Euclid, Ohio, 44121
Great Lakes Research Institute
Southfield, Michigan, 48075
Pediatric & Adolescent Center
Southgate, Michigan, 48195-1896
Javara Inc/Texas Health Care, PLLC d/b/a/ Privia Medical Group-North Texas
Stephenville, Texas, 76401
D&H Tamarac Research Center
Tamarac, Florida, 33321
Victoria Clinical Research Group
Victoria, Texas, 77901
Velocity Clinical Research - Salt Lake City
West Jordan, Utah, 84088
Panama3 sites
CEVAXIN Chorrera
La Chorrera, 07066
CEVAXIN Avenida Mexico
Panama City, 07093
CEVAXIN 24 de Diciembre
Panama City, 07114
About this study
Official title: A Phase 2, Randomized, Observer-blind Study to Evaluate the Safety, Reactogenicity, and Immunogenicity of mRNA-1345, an mRNA Vaccine Targeting Respiratory Syncytial Virus, in Children 2 to <18 Years of Age at High Risk of Respiratory Syncytial Virus Disease
Part A: The purpose is to evaluate the safety, reactogenicity, and immunogenicity of mRNA-1345 in children aged 2 to <5 years (Cohort 1) and in children at high risk of respiratory syncytial virus (RSV) disease 5 to <18 years of age (Cohort 2) to inform the dose level selection for the next phase of development (Phase 3).
Part B: The purpose is to provide surveillance for RSV disease for the next RSV season (6 months after re-enrollment) and safety follow-up for Cohort 1 participants that were enrolled and dosed in Part A.
- Conditions
- Respiratory Syncytial Virus
- Being tested
- mRNA-1345, Placebo
- Keywords
- Pediatric, mRNA-1345, RSV vaccine, Viral Diseases, Messenger RNA, Moderna
- Medical subject headings
- Virus Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
mRNA-1345Biological
Sterile liquid for injection
PlaceboBiological
0.9% sodium chloride (normal saline) injection
| Study group | Role | What they receive |
|---|---|---|
| Part A and Part B: Cohort 1 (2 to <5 Years of Age) | Experimental | Part A: Participants 2 to <5 years of age will receive either a single intramuscular (IM) injection of mRNA-1345 or placebo on Day 1. Part B: Participants will have the option to be re-enrolled into a 6-month safety-follow up period. Receives: Biological: mRNA-1345; Biological: Placebo |
| Part A: Cohort 2 (5 to <18 Years of Age) | Experimental | Participants 5 to <18 years of age will receive a single IM injection of mRNA-1345 on Day 1. Receives: Biological: mRNA-1345 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Part A (Cohorts 1 and 2): Number of Participants With Solicited Local and Systemic Adverse Reactions (ARs)
Solicited ARs were collected in an electronic diary (eDiary). Local ARs: injection site pain, erythema (redness), swelling/induration (hardness); and axillary (underarm) swelling or tenderness ipsilateral to the side of injection. Systemic ARs: fever, headache, fatigue, myalgia, arthralgia, nausea/vomiting, and chills. Note, not all solicited ARs were considered adverse events (AEs). Investigator reviewed whether the solicited AR was also to be recorded as an AE. A summary of serious AEs (SAEs) and nonserious AEs ("Other"), regardless of causality, is located in the "Reported Adverse Events" section.
Measured: Up to 7 days post-injection
Part A (Cohorts 1 and 2): Number of Participants With Unsolicited Adverse Events (AEs)
An AE was defined as any untoward medical occurrence associated with the use of a drug in humans, whether or not considered drug related. Any abnormal laboratory test result (hematology, clinical chemistry, or prothrombin time [PT]/partial thromboplastin time [PTT]) or other safety assessment (for example, electrocardiogram, radiological scan, vital sign measurement), including one that worsened from baseline and was considered clinically significant in the medical and scientific judgment of the Investigator was recorded as an AE. A summary of SAEs and all nonserious AEs ("Other"), regardless of causality, is located in the "Reported Adverse Events" section.
Measured: Up to 28 days post-injection
Part A (Cohorts 1 and 2): Number of Participants With Medically Attended AEs (MAAEs), Adverse Events of Special Interest (AESIs), Serious Adverse Events (SAEs), and AEs Leading to Study Discontinuation
A MAAE was an AE that led to an unscheduled visit to a healthcare practitioner. An AESI was an AE (serious or nonserious) of scientific and medical concern specific to the Sponsor's product or program, for which ongoing monitoring and immediate notification by the Investigator to the Sponsor are required. An SAE was defined as any AE that resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in disability, was a congenital anomaly/birth defect, or was an important medical event. A summary of SAEs and all nonserious AEs ("Other"), regardless of causality, is located in the "Reported Adverse Events" section.
Measured: Day 1 through end of Part A (Month 6)
Part B (Cohort 1): Number of Participants With RSV-RTD, Respiratory Syncytial Virus- Lower Respiratory Tract Disease (RSV-LRTD), Severe RSV-LRTD, Very Severe RSV-LRTD and RSV Hospitalization Classified by Clinical Assessment Team (CAT)
RSV-RTD: Runny nose or blocked nose or cough and confirmed RSV infection. RSV-LRTD: Cough or difficulty breathing (Based on Investigator's observation; difficulty breathing included signs of wheezing, stridor, tachypnoea, chest in-drawing or subcostal or intercostal retractions) and peripheral oxygen saturation (SpO2) <95%, or respiratory rate (RR) increased and confirmed RSV infection. RSV Severe-LRTD: Meeting the definition of RSV-LRTD and SpO2 <93%, or lower chest wall in-drawing. RSV Very Severe LRTD: Meeting the definition of RSV-LRTD and SpO2 <90%, or failure to respond/unconscious. RSV Hospitalization: Confirmed RSV and hospitalized for acute medical condition.
Measured: Day 1 through end of Part B (Month 6)
Secondary outcomes (13)
Part A (Cohort 1): Geometric Mean Titer (GMT) of Serum RSV Neutralizing Antibody
Antibody values reported as below lower limit of quantification (LLOQ) were replaced by 0.5*LLOQ. Values greater than the upper limit of quantification (ULOQ) were replaced by the ULOQ. LLOQ was 13 international units (IU)/milliliter (mL) for RSV-A and 10 IU/mL for RSV-B. ULOQ was 259061 IU/mL for RSV-A and 112476 IU/mL for RSV-B. 95% confidence interval (CI) for geometric mean (GM) value was calculated based on the t-distribution of the log-transformed values, then back transformed to the original scale for presentation.
Measured: Day 1, Day 29, and Month 6
Part A (Cohort 1): Geometric Mean Concentration (GMC) of Serum RSV Prefusion F (Pre-F) Binding Antibody
Antibody values reported as below LLOQ were replaced by 0.5*LLOQ. Values greater than ULOQ were replaced by the ULOQ. LLOQ was 35 arbitrary units (AU)/mL and ULOQ was 580553 AU/mL for RSV Pre-F immunoglobulin G (IgG) antibody. 95% CI for GM value was calculated based on the t-distribution of the log-transformed values, then back transformed to the original scale for presentation.
Measured: Day 1, Day 29, and Month 6
Part A (Cohort 1): Geometric Mean Fold Rise (GMFR) of Post-baseline/Baseline Neutralizing Antibody Titers
Antibody values reported as below lower LLOQ were replaced by 0.5*LLOQ. Values greater than the ULOQ were replaced by the ULOQ. LLOQ was 13 IU/mL for RSV-A and 10 IU/mL for RSV-B. ULOQ was 259061 IU/mL for RSV-A and 112476 IU/mL for RSV-B. 95% CI for GMFR (post-injection/baseline titers) was calculated based on the t-distribution of the differences in the log-transformed values between analysis timepoint and baseline, then back transformed to the original scale for presentation.
Measured: Day 29 and Month 6
Part A (Cohort 1): GMFR of Post-baseline/Baseline Binding Antibody Concentrations
Antibody values reported as below LLOQ were replaced by 0.5*LLOQ. Values greater than ULOQ were replaced by the ULOQ. LLOQ was 35 AU/mL and ULOQ was 580553 AU/mL for RSV Pre-F IgG antibody. 95% CI for GMFR (post-injection/baseline titers) was calculated based on the t-distribution of the differences in the log-transformed values between analysis timepoint and baseline, then back transformed to the original scale for presentation.
Measured: Day 29 and Month 6
Part A (Cohort 1): Percentage of Participants With Seroresponse in RSV Neutralizing Antibody
Seroresponse was defined as a change from below the LLOQ to equal or above 4 * LLOQ, or at least a 4-fold increase if baseline was equal to or above the LLOQ.
Measured: Baseline to Day 29 and Month 6
Part A (Cohort 1): Percentage of Participants With Seroresponse in RSV Pre-F Binding Antibody
Seroresponse was defined as a change from below the LLOQ to equal or above 4 * LLOQ, or at least a 4-fold increase if baseline was equal to or above the LLOQ.
Measured: Baseline to Day 29 and Month 6
Part A (Cohort 2): GMT of Serum RSV Neutralizing Antibody
Antibody values reported as below LLOQ were replaced by 0.5*LLOQ. Values greater than the ULOQ were replaced by the ULOQ. LLOQ was 13 IU/mL for RSV-A and 15 IU/mL for RSV-B. ULOQ was 259061 IU/mL for RSV-A and 162163 IU/mL for RSV-B. 95% CI for GM value was calculated based on the t-distribution of the log-transformed values, then back transformed to the original scale for presentation.
Measured: Day 1 and Day 29
Part A (Cohort 2): GMC of Serum RSV Pre-F Binding Antibody
Antibody values reported as below LLOQ were replaced by 0.5*LLOQ. Values greater than ULOQ were replaced by the ULOQ. LLOQ was 35 AU/mL and ULOQ was 580553 AU/mL for RSV Pre-F IgG antibody. 95% CI for GM value was calculated based on the t-distribution of the log-transformed values, then back transformed to the original scale for presentation.
Measured: Day 1 and Day 29
Part A (Cohort 2): GMFR of Post-baseline/Baseline Neutralizing Antibody Titers
Antibody values reported as below LLOQ were replaced by 0.5*LLOQ. Values greater than the ULOQ were replaced by the ULOQ. LLOQ was 13 IU/mL for RSV-A and 15 IU/mL for RSV-B. ULOQ was 259061 IU/mL for RSV-A and 162163 IU/mL for RSV-B. 95% CI for GMFR (post-injection/baseline titers) was calculated based on the t-distribution of the differences in the log-transformed values between analysis timepoint and baseline, then back transformed to the original scale for presentation.
Measured: Day 29
Part A (Cohort 2): GMFR of Post-baseline/Baseline Binding Antibody Concentrations
Antibody values reported as below LLOQ were replaced by 0.5*LLOQ. Values greater than ULOQ were replaced by the ULOQ. LLOQ was 35 AU/mL and ULOQ was 580553 AU/mL for RSV Pre-F IgG antibody. 95% CI for GMFR (post-injection/baseline titers) was calculated based on the t-distribution of the differences in the log-transformed values between analysis timepoint and baseline, then back transformed to the original scale for presentation.
Measured: Day 29
Part A (Cohort 2): Percentage of Participants With Seroresponse in RSV Neutralizing Antibody
Seroresponse was defined as a change from below the LLOQ to equal or above 4 * LLOQ, or at least a 4-fold increase if baseline was equal to or above the LLOQ.
Measured: Baseline to Day 29
Part A (Cohort 2): Percentage of Participants With Seroresponse in RSV Pre-F Binding Antibody
Seroresponse was defined as a change from below the LLOQ to equal or above 4 * LLOQ, or at least a 4-fold increase if baseline was equal to or above the LLOQ.
Measured: Baseline to Day 29
Part B (Cohort 1): Number of Participants With AESIs and SAEs
An AESI was an AE (serious or nonserious) of scientific and medical concern specific to the Sponsor's product or program, for which ongoing monitoring and immediate notification by the Investigator to the Sponsor are required. An SAE was defined as any AE that resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in disability, was a congenital anomaly/birth defect, or was an important medical event. A summary of SAEs and all nonserious AEs ("Other"), regardless of causality, is located in the "Reported Adverse Events" section.
Measured: Day 1 through Part B EOS (Month 6)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Oct 2023
- Study start24 Oct 2023
- Primary completion27 Jun 2025
- Study completion27 Jun 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for Respiratory Syncytial VirusStudies of the same condition, open and under way.
- More trials run by ModernaTX, Inc.The sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 349 participants (actual)
Sponsor and investigators
- Lead sponsor
- ModernaTX, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06097299
- Sponsor's protocol ID
- mRNA-1345-P202
- Other IDs
- 2024-000502-15
- Status last verified
- Jul 2026
- First submitted
- 18 Oct 2023
- Last updated
- 18 Aug 2026
- Results posted
- Yes, on ClinicalTrials.gov
- FDA-regulated drug
- Yes
- FDA-regulated device
- No