A Study of mRNA-1647 Cytomegalovirus Vaccine in Healthy Participants 9 to 15 Years of Age and Participants 16 to 25 Years of Age

NCT05575492 | Active Not Recruiting Phase 1 DMC FDA Drug

• 2 other identifiers: mRNA-1647-P1042022-001545-20
• Study Type: interventional
• Target: 873
• Locations: 3 countries
• Sites: 57

Brief Summary

The main purpose of study is to evaluate the safety and immunogenicity of different dose levels of mRNA-1647 versus control in healthy cytomegalovirus (CMV)-seronegative and CMV-seropositive female and male participants 9 to 15 years of age. In addition, mRNA-1647 will be evaluated in female participants 16 to 25 years as a comparator cohort.

Conditions

Cytomegalovirus

Keywords

mRNA-1647 Vaccine; CMV; Moderna

Outcome Measures

Primary Outcomes (7)

• Number of Solicited Local and Systemic Reactogenicity Adverse Reactions (ARs)

  Up to Day 176 (7 days after each study injection)

• Number of Unsolicited Adverse Events (AEs)

  Up to Day 197 (28 days after each study injection)

• Number of Medically Attended Adverse Events (MAAEs)

  Up to Day 347 (6 months after the last study injection)

• Number of Serious Adverse Events (SAEs), Adverse Events of Special Interest (AESIs), and AEs Leading to Discontinuation

  Up to Day 527 (end of study)

• Geometric Mean Titer (GMT) of Anti-CMV Neutralizing Antibodies (nAbs)

  Serum functional antibody levels against vaccine antigens will be measured by nAb titer against epithelial cell infection and nAb titer against fibroblast infection.

  Up to Day 527 (end of study)

• Geometric Mean Fold-Rise (GMFR) of Anti-CMV nAbs

  Serum functional antibody levels against vaccine antigens will be measured by nAb titer against epithelial cell infection and nAb titer against fibroblast infection.

  Up to Day 527 (end of study)

• Number of Participants with ≥2-Fold, 3-Fold, and 4-Fold increases Over Baseline of Anti-CMV Antibodies

  Serum functional antibody levels against vaccine antigens will be measured by nAb titer against epithelial cell infection and nAb titer against fibroblast infection.

  Up to Day 527 (end of study)

Secondary Outcomes (3)

• Geometric Mean Concentration (GMC) of Binding Anti-Glycoprotein B (gB) Specific Immunoglobulin G (IgG) and Anti-Pentamer Specific IgG

  Up to Day 527 (end of study)

• Number of Participants with ≥2-Fold, 3-Fold, and 4-Fold Increases Over Baseline of Binding Anti-gB and Anti-pentamer Specific IgG

  Up to Day 527 (end of study)

• GMFR of Binding Anti-gB and Anti-pentamer Specific IgG

  Up to Day 527 (end of study)

Study Arms (7)

mRNA-1647 Dose A

EXPERIMENTAL

CMV-seronegative or CMV-seropositive participants 9 to 15 years of age will receive mRNA-1647 at Dose Level A by intramuscular (IM) injection given as a 3-injection series on Day 1, Month 2, and Month 6.

Biological: mRNA-1647

mRNA-1647 Dose B

EXPERIMENTAL

CMV-seronegative or CMV-seropositive participants 9 to 15 years of age will receive mRNA-1647 at Dose Level B by IM injection given as a 3-injection series on Day 1, Month 2, and Month 6.

Biological: mRNA-1647

mRNA-1647 Dose C

EXPERIMENTAL

CMV-seronegative or CMV-seropositive participants 9 to 15 years of age and 16 to 25 years of age will receive mRNA-1647 at Dose Level C by IM injection given as a 3-injection series on Day 1, Month 2, and Month 6.

Biological: mRNA-1647

Dose Expansion: mRNA-1647 (3-dose Schedule)

EXPERIMENTAL

CMV-seronegative or CMV-seropositive participants 9 to 15 years of age will receive mRNA-1647 at selected dose level by IM injection given as a 3-injection series on Day 1, Month 2, and Month 6.

Biological: mRNA-1647

Dose Expansion: mRNA-1647 (2-dose Schedule)

EXPERIMENTAL

CMV-seronegative participants 9 to 15 years of age will receive mRNA-1647 at selected dose level by IM injection given as a 2-injection series on Day 1 and Month 6.

Biological: mRNA-1647

Dose Expansion: Placebo (3-dose Schedule)

PLACEBO COMPARATOR

CMV-seronegative or CMV-seropositive participants 9 to 15 years of age will receive placebo by IM injection given as a 3-injection series on Day 1, Month 2, and Month 6.

Other: Placebo

Dose Expansion: Placebo (2-dose Schedule)

PLACEBO COMPARATOR

CMV-seronegative participants 9 to 15 years of age will receive placebo by IM injection given as a 2-injection series on Day 1 and Month 6.

Other: Placebo

Interventions

mRNA-1647 BIOLOGICAL

Sterile liquid for injection

Dose Expansion: mRNA-1647 (2-dose Schedule); Dose Expansion: mRNA-1647 (3-dose Schedule); mRNA-1647 Dose A; mRNA-1647 Dose B; mRNA-1647 Dose C

Placebo OTHER

0.9% sodium chloride injection (normal saline)

Dose Expansion: Placebo (2-dose Schedule); Dose Expansion: Placebo (3-dose Schedule)

Eligibility Criteria

• Age: 9 Years - 25 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Child (0-17), Adult (18-64)

You may qualify if:

• Is a female or male 9 to 15 years of age or is a female 16 to 25 years of age at the time of consent.
• Is in good general health, in the opinion of the Investigator, and is capable of complying with study procedures.
• For the CMV-seronegative cohorts: At the Screening visit, is CMV IgG-negative and CMV immunoglobulin M (IgM)-negative.
• For the CMV-seropositive cohorts: At the Screening visit, is CMV IgG-positive and CMV IgM-negative, CMV IgG-positive and CMV IgM-positive, or CMV IgG-positive and CMV IgM-indeterminate. Participants with an isolated positive or indeterminate result for CMV IgM (that is, CMV IgG-negative and either CMV IgM-positive or CMV IgM-indeterminate) will not be eligible for enrollment but may be rescreened after at least 6 weeks from the initial CMV Screening. Participants with an indeterminate result for CMV IgG, regardless of IgM result, will not be eligible for enrollment but may be rescreened after at least 6 weeks from the initial CMV screening.
• If 9 to 15 years of age, has a body mass index (BMI) at or above the third percentile according to World Health Organization (WHO) Child Growth Standards. If 16 to 25 years of age: has a BMI of 15 to 35 kilograms (kg)/square meter (m\^2).
• For female participants of childbearing potential: negative pregnancy test, adequate contraception or has abstained from all activities that could result in pregnancy for at least 28 days prior to Day 1, agreement to continue adequate contraception through 3 months following vaccine administration.

You may not qualify if:

• Has a history of a diagnosis or condition that, in the judgment of Investigator, is clinically unstable or may affect participant safety, assessment of safety endpoints, assessment of immune response, or adherence to study procedures. Clinically unstable is defined as diagnosis or condition requiring significant changes in management or medication within the 2 months prior to Screening and includes ongoing workup of an undiagnosed illness that could lead to a new diagnosis or condition.
• Has received, or plans to receive, any nonstudy vaccine \< 28 days prior to or after any study injection.
• Has a screening liver function test (aspartate aminotransferase, alanine aminotransferase, total bilirubin) or a screening creatinine result of Toxicity Grade ≥1.
• Has a Screening hematology or coagulation result of Toxicity Grade ≥1.
• Is acutely ill or febrile (body temperature ≥38.0 degrees Celsius \[°C\]/100.4 degrees Fahrenheit \[°F\]) at the Screening Visit.
• Has received systemic immunosuppressants or immune-modifying drugs for \> 14 days in total within 6 months prior to the day of enrollment (for corticosteroids, ≥1 milligrams (mg)/kg/day or ≥10 mg/day prednisone equivalent).
• Has received an antiviral with activity against CMV (ganciclovir, valganciclovir, foscarnet, cidofovir, letermovir, acyclovir, valacyclovir) \<2 weeks prior to the day of the first study injection (Day 1) or plans to do so during the course of the study.
• Reports a history of myocarditis, pericarditis, or myopericarditis.
• Has reported medical history of hepatitis B, hepatitis C, or human immunodeficiency virus (HIV); or a positive screening test for hepatitis B surface antigen (HBsAg), hepatitis C antibodies, or HIV 1 or 2 antibodies.
• Has previously received an investigational CMV vaccine.
• Has received systemic immunoglobulins or blood products \<3 months prior to the day of the first study injection (Day 1).
• Has donated ≥ 450 milliliter (mL) of blood products \<28 days prior to the day of the first study injection (Day 1).
• Has participated in an interventional clinical study \<28 days prior to the day of the first study injection (Day 1) or plans to do so while enrolled in the study.

Sponsors & Collaborators

• ModernaTX, Inc.: lead

Study Sites (57)

Paradigm Clinical Research Institute Inc - ClinEdge - PPDS

La Mesa, California, 91942-3189, United States

Location

Velocity Clinical Research - San Diego - PPDS

La Mesa, California, 91942, United States

Location

Benchmark Research - Sacramento -Hypercore- PPDS

Sacramento, California, 95864, United States

Location

Tekton Research - Fort Collins - Platinum - PPDS

Fort Collins, Colorado, 80525-5752, United States

Location

Velocity Clinical Research (Washington)- PPDS

Washington D.C., District of Columbia, 20016, United States

Location

Prohealth Research Center

Doral, Florida, 33166-6613, United States

Location

University of Florida Jacksonville

Jacksonville, Florida, 32209, United States

Location

Clinical Neurosciences Solutions Inc. (Orlando-East South St)

Orlando, Florida, 32801-2987, United States

Location

Palm Harbor Dermatology

Tampa, Florida, 33609-2230, United States

Location

Santos Research Center

Tampa, Florida, 33615-3219, United States

Location

Children's Healthcare of Atlanta

Atlanta, Georgia, 30322-1014, United States

Location

iResearch Atlanta - CenExel - PPDS

Decatur, Georgia, 30030-3438, United States

Location

Clinical Research Prime - ClinEdge - PPDS

Idaho Falls, Idaho, 83404-5305, United States

Location

Benchmark Research - Covington - HyperCore- PPDS

Covington, Louisiana, 70433, United States

Location

Tulane Medical Center

New Orleans, Louisiana, 70112-2632, United States

Location

University of Maryland School of Medicine

Baltimore, Maryland, 21201-1509, United States

Location

The Pediatric Centre

Columbia, Maryland, 21045, United States

Location

The Pediatric Centre of Frederick

Frederick, Maryland, 21702, United States

Location

Wayne State University

Detroit, Michigan, 48201, United States

Location

University of Minnesota

Minneapolis, Minnesota, 55455, United States

Location

Velocity Clinical Research - Gulfport

Gulfport, Mississippi, 39503, United States

Location

Velocity Clinical Research (Lincoln-Nebraska) - PPDS

Lincoln, Nebraska, 68510, United States

Location

Velocity Clinical Research (Norfolk - Nebraska) - PPDS

Norfolk, Nebraska, 68701-7701, United States

Location

Velocity Clinical Research (Omaha-Nebraska) - Platinum - PPDS

Omaha, Nebraska, 68134-3664, United States

Location

Albuquerque Clinical Trials Inc - Clinedge - PPDS

Albuquerque, New Mexico, 87102-2619, United States

Location

Velocity Clinical Research -Albuquerque -PPDS

Albuquerque, New Mexico, 87102-3644, United States

Location

Velocity Clinical Research (Binghamton - New York) - PPDS

Binghamton, New York, 13901-1046, United States

Location

Rochester Clinical Research, Inc

Rochester, New York, 14609-3173, United States

Location

OnSite Clinical Solutions, LLC - ClinEdge - PPDS

Charlotte, North Carolina, 28277-4859, United States

Location

Tekton Research - Oklahoma- PPDS

Edmond, Oklahoma, 73013, United States

Location

Lynn Institute of Norman - ERN - PPDS

Norman, Oklahoma, 73072-3251, United States

Location

Velocity Clinical Research - Medford - PPDS

Medford, Oregon, 97504-7738, United States

Location

Meharry Medical College

Nashville, Tennessee, 37208, United States

Location

Tekton Research - Texas - PPDS

Austin, Texas, 78705, United States

Location

Tekton Research - Beaumont - Platinum - PPDS

Beaumont, Texas, 77706-3061, United States

Location

Benchmark Research - Fort Worth - HyperCore -PPDS

Fort Worth, Texas, 76135, United States

Location

University of Texas Medical Branch (UTMB)

Galveston, Texas, 77550, United States

Location

West Houston Clinical Research - Hunt - PPDS

Houston, Texas, 77055-1626, United States

Location

Victoria Clinical Research Group

Port Lavaca, Texas, 77979, United States

Location

Benchmark Research - San Angelo - HyperCore - PPDS

San Angelo, Texas, 76904, United States

Location

Tekton Research - Texas - Platinum - PPDS

San Antonio, Texas, 78229, United States

Location

DM Clinical Research - ERN- PPDS

Tomball, Texas, 77375, United States

Location

Crossroads Clinical Research (Victoria)

Victoria, Texas, 77901, United States

Location

JBR Clinical Research - CenExel JBR - PPDS

Salt Lake City, Utah, 84107-4536, United States

Location

M.A.G.I.C. Clinic Ltd. Metabolics and Genetics in Calgary

Calgary, Alberta, Canada

Location

ALTA Clinical Research Inc

Edmonton, Alberta, Canada

Location

CARe Clinic

Red Deer, Alberta, Canada

Location

Canadian Center for Vaccinology

Halifax, Nova Scotia, Canada

Location

Hamilton Medical Research Group

Hamilton, Ontario, Canada

Location

Bluewater Clinical Research Group

Sarnia, Ontario, Canada

Location

Centre Hospitalier Universitaire Sainte-Justine

Montreal, Quebec, Canada

Location

Southampton General Hospital

Southampton, Hampshire, United Kingdom

Location

Lakeside Healthcare

Corby, Northamptonshire, United Kingdom

Location

Sheffield Children's Hospital

Sheffield, South Yorkshire, United Kingdom

Location

Queen Elizabeth Hospital

Birmingham, United Kingdom

Location

Noah's Ark Children's Hospital for Wales

Cardiff, United Kingdom

Location

St. George Hospital

London, United Kingdom

Location

MeSH Terms

Interventions

mRNA-1647 cytomegalovirus vaccine

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: Part 1 of this study will be open-label and blinding is not applicable. Part 2 of the study will be observer-blinded.
• Purpose: PREVENTION
• Intervention Model: SEQUENTIAL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Model Details: Part 1: Dose-escalating, non-randomized Part 2: Randomized

Study Record Dates

• First Submitted: October 7, 2022
• First Posted: October 12, 2022
• Study Start: November 7, 2022
• Primary Completion (Estimated): January 15, 2027
• Study Completion (Estimated): January 15, 2027
• Last Updated: December 15, 2025

Record last verified: 2025-12

Locations

CA (7); GB (6); US (44)