A Study to Investigate The Safety, Tolerability, And Immune Response of a Range of Doses of mRNA-1769 Compared With Placebo in Healthy Participants From ≥18 Years of Age to <50 Years of Age

NCT ID: NCT05995275

Last Updated: 2025-07-16

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

COMPLETED

Clinical Phase

PHASE1/PHASE2

Total Enrollment

351 participants

Study Classification

INTERVENTIONAL

Study Start Date

2023-08-15

Study Completion Date

2025-07-08

Brief Summary

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The goal of this study is to assess the safety, tolerability and immunogenicity of mRNA-1769 in healthy adult participants.

Detailed Description

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Conditions

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Smallpox Mpox

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

SEQUENTIAL

Primary Study Purpose

PREVENTION

Blinding Strategy

QUADRUPLE

Participants Caregivers Investigators Outcome Assessors

Study Groups

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mRNA-1769 Dose A

Participants will receive intramuscular (IM) injection of mRNA-1769 at Dose A on Day 1 and Day 29.

Group Type EXPERIMENTAL

mRNA-1769

Intervention Type BIOLOGICAL

Sterile liquid for injection

mRNA-1769 Dose B

Participants will receive IM injection of mRNA-1769 at Dose B on Day 1 and Day 29.

Group Type EXPERIMENTAL

mRNA-1769

Intervention Type BIOLOGICAL

Sterile liquid for injection

mRNA-1769 Dose C

Participants will receive IM injection of mRNA-1769 at Dose C on Day 1 and Day 29.

Group Type EXPERIMENTAL

mRNA-1769

Intervention Type BIOLOGICAL

Sterile liquid for injection

Placebo

Participants will receive IM injection of placebo matched to mRNA-1769 on Day 1 and Day 29.

Group Type PLACEBO_COMPARATOR

Placebo

Intervention Type OTHER

0.9% sodium chloride injection (normal saline)

Interventions

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mRNA-1769

Sterile liquid for injection

Intervention Type BIOLOGICAL

Placebo

0.9% sodium chloride injection (normal saline)

Intervention Type OTHER

Eligibility Criteria

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Inclusion Criteria

* Has a body mass index (BMI) between ≥18 kilogram per square meter (kg/m\^2) to ≤39 kg/m\^2.
* For female participants of childbearing potential: must have a negative highly sensitive pregnancy test with 28 days before the first dose of study drug, uses approved contraception during the study intervention period and for at least 3 months after the last dose of study drug, and not currently breastfeeding.

Exclusion Criteria

* History of smallpox vaccination, vaccination with any poxvirus-based vaccine, history of of/or recent exposure to Mpox (MPX) (defined as close contact with a confirmed case of MPX within the past 14 days).
* Participant should not have any significant, progressive, unstable, or uncontrolled clinical condition, including any condition that may affect participant safety, assessment of safety endpoints, assessment of immune response, or adherence to study procedures per Investigator judgement.
* Participant is undergoing investigations for a potential chronic medical disorder.
* Bleeding disorder considered a contraindication to IM injection or phlebotomy.
* Dermatologic conditions that could affect local solicited AR assessments.
* History of anaphylactic reaction or allergic reactions that required medical intervention following any vaccine.
* Known or suspected allergy to any component of mRNA-1769.
* History of malignancy within previous 10 years (excluding non-melanoma skin cancer).
* Participant has any medical, psychiatric, or occupational condition, including reported history of drug or alcohol abuse, that, in the opinion of the Investigator, might pose additional risk due to participation in the study or could interfere with the interpretation of study results.
* Participant has received systemic immunosuppressants or immune-modifying drugs for \>14 days in total within 6 months prior to Screening (for corticosteroids, ≥10 mg/day of prednisone or equivalent) or is anticipating the need for immunosuppressive treatment at any time during participation in the study. Topical tacrolimus is allowed if not used within 14 days prior to the day of enrolment. Participants may be rescheduled for enrolment if they no longer meet this criterion within the Screening Period. Inhaled, nasal, and topical steroids are allowed.
* Receipt or planned receipt of: Any vaccine(s), authorised or approved by local health agency, including mRNA vaccine, ≤28 days prior to the first injection through 28 days after the last dose of investigational (IMP).
* Intravenous blood products (red cells, platelets, immunoglobulins) within 3 months prior to the first injection up to the end of the study.
* Participated in an interventional study/received an investigational product within 28 days prior to the Screening Period or plans to do so while enroled in this study.
Minimum Eligible Age

18 Years

Maximum Eligible Age

49 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes

Sponsors

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ModernaTX, Inc.

INDUSTRY

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Locations

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Bradford Teaching Hospitals NHS Foundation Trust

Bradford, , United Kingdom

Site Status

University Hospitals Bristol and Weston NHS Foundation Trust

Bristol, , United Kingdom

Site Status

Lakeside Healthcare Research

Corby, , United Kingdom

Site Status

University Hospitals of Leicester

Leicester, , United Kingdom

Site Status

Liverpool University Hospitals NHS Foundation Trust

Liverpool, , United Kingdom

Site Status

Barts Health NHS Trust

London, , United Kingdom

Site Status

University College London Hospitals

London, , United Kingdom

Site Status

Royal Free London NHS Foundation Trust

London, , United Kingdom

Site Status

Chelsea and Westminster Hospital NHS Foundation Trust

London, , United Kingdom

Site Status

Medicines Evaluation Unit

Manchester, , United Kingdom

Site Status

Centre for Clinical Vaccinology and Tropical Medicine (CCVTM)

Oxford, , United Kingdom

Site Status

North Wales Clinical Research Facility Centre

Wrexham, , United Kingdom

Site Status

Countries

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United Kingdom

Other Identifiers

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mRNA-1769-P101

Identifier Type: -

Identifier Source: org_study_id

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