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Virus Therapy

mRNA-1647 Vaccine for Cytomegalovirus Infection

Phase 2
Research Sponsored by ModernaTX, Inc.
Eligibility Criteria Checklist
Specific guidelines that determine who can or cannot participate in a clinical trial
Must have
Receipt of an allogeneic HCT
Be older than 18 years old
Screening 3 weeks
Treatment Varies
Follow Up month 9
Awards & highlights

Study Summary

This trial will study if a new drug (mRNA-1647) can help prevent a virus infection after a stem cell transplant.

Who is the study for?
This trial is for adults who've had a bone marrow transplant, are at high risk for CMV infection, and have working major organs. They must not be pregnant or breastfeeding, agree to use contraception, and can't have HIV or recent treatments that weaken the immune system.Check my eligibility
What is being tested?
The study tests mRNA-1647 vaccine's effectiveness in preventing significant CMV infections after stopping standard anti-CMV drugs post-transplant. Participants will either receive the vaccine or a placebo to compare results.See study design
What are the potential side effects?
Potential side effects of mRNA-1647 may include typical reactions seen with other vaccines such as pain at injection site, fatigue, headache, muscle pain, chills, fever and nausea.

Eligibility Criteria

Inclusion Criteria

You may be eligible if you check “Yes” for the criteria below
I have received a stem cell transplant from a donor.


Screening ~ 3 weeks
Treatment ~ Varies
Follow Up ~month 9
This trial's timeline: 3 weeks for screening, Varies for treatment, and month 9 for reporting.

Treatment Details

Study Objectives

Outcome measures can provide a clearer picture of what you can expect from a treatment.
Primary outcome measures
Number of Participants with Grade ≥3 Acute Graft-Versus-Host Disease (GVHD)
Number of Participants with Serious Adverse Events (SAEs)
Number of Participants with Severe AEs
+3 more
Secondary outcome measures
Duration of CMV Treatment
Duration of CMV Viremia
Geometric Mean Concentration (GMC) of Anti-gB-Specific Immunoglobulin G (IgG) and Anti-Pentamer-Specific IgG as Measured by Enzyme-Linked Immunosorbent Assay (ELISA)
+7 more

Trial Design

2Treatment groups
Experimental Treatment
Placebo Group
Group I: mRNA-1647Experimental Treatment1 Intervention
Participants will receive mRNA-1647 vaccine by intramuscular (IM) injection on Day 42, Day 67, and Day 92, and a booster dose on Day 180.
Group II: PlaceboPlacebo Group1 Intervention
Participants will receive mRNA-1647 vaccine matching placebo by IM injection on Day 42, Day 67, and Day 92, and a booster dose on Day 180.
First Studied
Drug Approval Stage
How many patients have taken this drug
Completed Phase 2

Find a Location

Who is running the clinical trial?

ModernaTX, Inc.Lead Sponsor
107 Previous Clinical Trials
61,377,901 Total Patients Enrolled

Media Library

mRNA-1647 Cytomegalovirus (CMV) Vaccine (Virus Therapy) Clinical Trial Eligibility Overview. Trial Name: NCT05683457 — Phase 2
Cytomegalovirus Research Study Groups: Placebo, mRNA-1647
Cytomegalovirus Clinical Trial 2023: mRNA-1647 Cytomegalovirus (CMV) Vaccine Highlights & Side Effects. Trial Name: NCT05683457 — Phase 2
mRNA-1647 Cytomegalovirus (CMV) Vaccine (Virus Therapy) 2023 Treatment Timeline for Medical Study. Trial Name: NCT05683457 — Phase 2

Frequently Asked Questions

These questions and answers are submitted by anonymous patients, and have not been verified by our internal team.

Are there any available openings in this research endeavor for participants?

"Data hosted on clinicaltrials.gov informs us that this research trial is no longer seeking participants, having been initially posted on January 30th 2023 and last updated on April 1st 2023. Despite this, there are still 769 ongoing medical trials actively recruiting patients at present."

Answered by AI

What risks have been identified for those receiving mRNA-1647 treatments?

"Data indicating the safety of mRNA-1647 is present, thus giving a score of 2. There isn't any evidence yet that this medication has efficacy in patients at this time."

Answered by AI
~124 spots leftby Aug 2025