Dose-Finding Trial to Evaluate the Safety and Immunogenicity of Cytomegalovirus (CMV) Vaccine mRNA-1647 in Healthy Adults
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The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. |
ClinicalTrials.gov Identifier: NCT04232280 |
Recruitment Status :
Active, not recruiting
First Posted : January 18, 2020
Last Update Posted : December 21, 2021
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Condition or disease | Intervention/treatment | Phase |
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Cytomegalovirus Infection | Biological: mRNA-1647 Other: Placebo | Phase 2 |
Study Type : | Interventional (Clinical Trial) |
Actual Enrollment : | 315 participants |
Allocation: | Randomized |
Intervention Model: | Sequential Assignment |
Masking: | Double (Participant, Investigator) |
Masking Description: | Observer-Blind |
Primary Purpose: | Prevention |
Official Title: | A Phase 2, Randomized, Observer-Blind, Placebo-Controlled, Dose-Finding Trial to Evaluate the Safety and Immunogenicity of Cytomegalovirus Vaccine mRNA-1647 in Healthy Adults |
Actual Study Start Date : | January 9, 2020 |
Estimated Primary Completion Date : | December 31, 2022 |
Estimated Study Completion Date : | December 31, 2022 |

Arm | Intervention/treatment |
---|---|
Experimental: mRNA-1647 Low Dose
Participants will receive mRNA-1647 vaccine at the Low Dose by intramuscular (IM) injection on Day 1, Day 56, and Day 168.
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Biological: mRNA-1647
Lyophilized product that is reconstituted with saline then diluted with a special diluent to reach the desired concentration |
Experimental: mRNA-1647 Medium Dose
Participants will receive mRNA-1647 vaccine at the Medium Dose by IM injection on Day 1, Day 56, and Day 168.
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Biological: mRNA-1647
Lyophilized product that is reconstituted with saline then diluted with a special diluent to reach the desired concentration |
Experimental: mRNA-1647 High Dose
Participants will receive mRNA-1647 vaccine at the High Dose by IM injection on Day 1, Day 56, and Day 168.
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Biological: mRNA-1647
Lyophilized product that is reconstituted with saline then diluted with a special diluent to reach the desired concentration |
Placebo Comparator: Placebo
Participants will receive placebo matching to the mRNA-1647 vaccine dose by IM injection on Day 1, Day 56, and Day 168.
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Other: Placebo
0.9% sodium chloride (normal saline) injection |
- Frequency of Solicited Local and Systemic Adverse Reactions (ARs) [ Time Frame: Up to Day 175 (7 days following last dose administration) ]
- Frequency of Unsolicited Adverse Events (AEs) [ Time Frame: Up to Day 196 (28 days following last dose administration) ]
- Frequency of Medically-Attended Adverse Events (MAAEs) [ Time Frame: Up to Day 336 (6 months following last dose administration) ]
- Frequency of Serious Adverse Events (SAEs) [ Time Frame: Up to Day 504 (1 year following last dose administration) ]
- Change from Baseline in Geometric Mean Titer (GMT) of Serum Neutralizing Anti-CMV Antibodies Against Epithelial Cell Infection and Against Fibroblast Infection [ Time Frame: Baseline, Day 29, Day 56, Day 84, Day 168, Day 196, Day 336, Day 504 ]
- Proportion of Participants with ≥2-Fold, 3-Fold, and 4-Fold Increases in Neutralizing Antibodies (nAb) over Baseline Against Epithelial Cell Infection and Against Fibroblast Infection [ Time Frame: Day 29, Day 56, Day 84, Day 168, Day 196, Day 336, and Day 504 ]
- Change from Baseline in GMT of Anti-Glycoprotein B (gB) Specific Immunoglobulin G (IgG) and Anti-Pentamer Specific IgG as Measured by Enzyme-Linked Immunosorbent Assay (ELISA) of Post-Baseline/Baseline Titers [ Time Frame: Baseline, Day 1, Day 29, Day 56, Day 84, Day 168, Day 196, Day 336, Day 504 ]
- Change from Baseline in Associated GMR of Anti-gB Specific IgG and Anti-Pentamer Specific IgG as Measured by ELISA of Post-Baseline/Baseline Titers [ Time Frame: Baseline, Day 1, Day 29, Day 56, Day 84, Day 168, Day 196, Day 336, Day 504 ]
- Change from Baseline in GMT of Serum nAb Against Epithelial Cell Infection and Against Fibroblast Infection at Each Timepoint, in the CMV-Seropositive Group and in the CMV-Seronegative Group [ Time Frame: Baseline, Day 1, Day 29, Day 56, Day 84, Day 168, Day 196, Day 336, Day 504 ]
- Change from Baseline in GMR of Serum nAb Against Epithelial Cell Infection and Against Fibroblast Infection at Each Timepoint, in the CMV-Seropositive Group and in the CMV-Seronegative Group [ Time Frame: Baseline, Day 1, Day 29, Day 56, Day 84, Day 168, Day 196, Day 336, Day 504 ]
- Proportion of Participants with ≥2-Fold, 3-Fold, and 4-Fold Increases over Baseline of Serum nAb Against Epithelial Cell Infection and Against Fibroblast Infection [ Time Frame: Day 1, Day 29, Day 56, Day 84, Day 168, Day 196, Day 336, and Day 504 ]
- Change from Baseline in GMT of Antigen-Specific IgG (ELISA) at each Timepoint in the CMV-Seropositive and CMV-Seronegative Groups [ Time Frame: Baseline, Day 1, Day 29, Day 56, Day 84, Day 168, Day 196, Day 336, Day 504 ]
- Change from Baseline in GMR of Antigen-Specific IgG (ELISA) at each Timepoint in the CMV-Seropositive and CMV-Seronegative Groups [ Time Frame: Baseline, Day 1, Day 29, Day 56, Day 84, Day 168, Day 196, Day 336, Day 504 ]

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.
Ages Eligible for Study: | 18 Years to 40 Years (Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | Yes |
Inclusion Criteria:
- Male or female 18-40 years of age (Part 1); Female 18-40 years of age (Part 2)
- Understands and agrees to comply with the trial procedures and provides written informed consent
- According to the assessment of the Investigator, is in good general health and is capable of complying with trial procedures
- Body mass index (BMI) 18-35 kilograms/meter (kg/m^2)
- Female participants must either be of non-childbearing potential or use acceptable methods of contraception from at least 28 days prior to the first vaccination and through 3 months following last vaccination and is not breastfeeding.
- Male participants must agree to practice adequate contraception from the time of the first vaccination and through 3 months after the last vaccination.
Exclusion Criteria:
- Acutely ill or febrile on the day of the first vaccination
- Prior receipt of any CMV vaccine
- Abnormal screening safety laboratory test results
- 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 trial procedures
- Has received or plans to receive a vaccine ≤28 days prior to the first vaccination or plans to receive a non-study vaccine within 28 days prior to or after any study vaccination, except for any licensed influenza vaccine which can be administered >14 days before or after any study vaccination. COVID-19 vaccines (regardless of manufacturer) may be administered >7 days but preferably >14 days before or after any study vaccination, with the intention of prioritizing COVID-19 vaccination over all other considerations.
- Prior receipt of chronic systemic immunosuppressants or immune-modifying drugs
- Receipt of intravenous immunoglobulins or plasma products within 3 months prior to the day of the first study vaccination
- Previous receipt of medications in lipid nanoparticle (LNP) formulation (Part 1 participants only)
- Has donated ≥450 milliliters (mL) of blood products within 28 days of the Screening visit
- Participated in an interventional clinical trial within 28 days prior to the day of enrollment
- Is an immediate family member or household member of trial personnel

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT04232280
United States, California | |
Benchmark Research | |
Sacramento, California, United States, 95864 | |
United States, Illinois | |
Optimal Research | |
Peoria, Illinois, United States, 61614 | |
United States, Kansas | |
Johnson County Clin-Trials | |
Lenexa, Kansas, United States, 66219 | |
United States, Kentucky | |
Alliance for Multispecialty Research | |
Lexington, Kentucky, United States, 40509 | |
United States, Ohio | |
Aventiv Research Inc | |
Columbus, Ohio, United States, 43213-6523 | |
United States, Texas | |
Tekton Research Inc | |
Austin, Texas, United States, 78745 | |
Crossroads Clinical Research | |
Victoria, Texas, United States, 77901 | |
United States, Utah | |
Foothill Family Clinic | |
Salt Lake City, Utah, United States, 84109 | |
Foothill Family Clinic-South Clinic | |
Salt Lake City, Utah, United States, 84121 |
Responsible Party: | ModernaTX, Inc. |
ClinicalTrials.gov Identifier: | NCT04232280 |
Other Study ID Numbers: |
mRNA-1647-P202 |
First Posted: | January 18, 2020 Key Record Dates |
Last Update Posted: | December 21, 2021 |
Last Verified: | December 2021 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | No |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
Moderna mRNA-1647 Cytomegalovirus CMV Cytomegalovirus Vaccine Cytomegalovirus Infections |
Cytomegalovirus Congenital Virus Diseases Infection Viral DNA Virus Infections Messenger RNA |
Infections Cytomegalovirus Infections Herpesviridae Infections DNA Virus Infections Virus Diseases |