Safety and Immunogenicity Study of Self-Amplifying RNA Pandemic Influenza Vaccine in Adults

NCT ID: NCT06602531

Last Updated: 2026-01-30

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

Total Enrollment

212 participants

Study Classification

INTERVENTIONAL

Study Start Date

2024-12-10

Study Completion Date

2025-12-05

Brief Summary

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The goal of this clinical trial is to evaluate the safety and immune responses of three different dose levels a self-amplifying RNA pandemic influenza vaccine (ARCT-2304) in adults. The key objectives of the study are:

* To evaluate safety and reactogenicity of different dose levels of the ARCT-2304 vaccine
* To describe the Immune responses of different dose levels of the ARCT-2304 vaccine as measured by hemagglutination inhibition (HAI) and neuraminidase enzyme-linked lectin (ELLA) antibody responses

Researchers will compare the results with licensed influenza vaccines to select the most optimal dose level and schedule for vaccine administration in terms of safety and immunogenicity for further development of the vaccine.

Participants will receive 2 doses of the ARCT-2304 vaccine or 1 dose of licensed influenza vaccine and 1 dose of placebo.

They will be asked:

* to complete a daily diary for 7 days after each vaccination, answering questions how they have been feeling on that day.
* to provide blood samples at each visit in the clinic
* to comply with all study visits and procedures (e.g., be available for planned telephone contacts and unscheduled clinic visits, if required)

Detailed Description

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Phase 1, first-in-human, randomized, controlled, observer blind, dose level and schedule-finding study, to evaluate the safety, reactogenicity, and immunogenicity of a self-amplifying mRNA pandemic influenza (H5N1) vaccine (ARCT-2304) when administered as a 2-dose vaccination series to healthy adults in comparison with an inactivated influenza vaccine.

Study drug (ARCT-2304 or control) will be administered as a 2-dose vaccination series as an intramuscular (IM) injection. The study comprises two parts.

In Part 1, 120 participants (young adults) will be randomized to one of the three dose levels of the ARCT-2304 vaccine or control vaccine. Participants will be further randomized to one of the two different vaccination schedules.

In Part 2, 80 participants (older adults) will be randomized to one of the three dose levels of the ARCT-2304 vaccine or control vaccine. Participants will be further randomized to one of the two different vaccination schedules.

Investigational Vaccine: ARCT-2304

Control Vaccines: licensed influenza vaccines

Conditions

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Influenza, Human

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

Primary Study Purpose

PREVENTION

Blinding Strategy

QUADRUPLE

Participants Caregivers Investigators Outcome Assessors
Observer blind

Study Groups

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Control, Schedule 2, Older Adults

Older Adults Control Vaccine (dose 1) and placebo (dose 2) administered through intramuscular injection in the deltoid muscle.

Interventions: 2-dose regimen, schedule 2 Investigational Vaccine: Comparator vaccine older adult and saline placebo vaccine

Group Type ACTIVE_COMPARATOR

Control vaccine older adults

Intervention Type BIOLOGICAL

Each participant will receive one intramuscular (IM) dose into the deltoid muscle.

Placebo Vaccine

Intervention Type OTHER

Each participant will receive one intramuscular (IM) dose into the deltoid muscle.

Low dose of ARCT-2304, Schedule 2, Older Adults

Low dose of ARCT-2304 administered through intramuscular injection in the deltoid muscle.

Interventions: 2-dose regimen, schedule 2 Investigational Vaccine: ARCT-2304

Group Type EXPERIMENTAL

ARCT-2304

Intervention Type BIOLOGICAL

Each participant will receive 2-dose regimen intramuscular (IM) dose into the deltoid muscle.

Mid dose of ARCT-2304, Schedule 2, Older Adults

Mid dose of ARCT-2304 administered through intramuscular injection in the deltoid muscle.

Interventions: 2-dose regimen, schedule 2 Investigational Vaccine: ARCT-2304

Group Type EXPERIMENTAL

ARCT-2304

Intervention Type BIOLOGICAL

Each participant will receive 2-dose regimen intramuscular (IM) dose into the deltoid muscle.

High dose of ARCT-2304, Schedule 2, Older Adults

High dose of ARCT-2304 administered through intramuscular injection in the deltoid muscle.

Interventions: 2-dose regimen, schedule 2 Investigational Vaccine: ARCT-2304

Group Type EXPERIMENTAL

ARCT-2304

Intervention Type BIOLOGICAL

Each participant will receive 2-dose regimen intramuscular (IM) dose into the deltoid muscle.

Low dose of ARCT-2304, Schedule 1, Young Adults

Low dose of ARCT-2304 administered through intramuscular injection in the deltoid muscle.

Interventions: 2-dose regimen, schedule 1 Investigational Vaccine: ARCT-2304

Group Type EXPERIMENTAL

ARCT-2304

Intervention Type BIOLOGICAL

Each participant will receive 2-dose regimen intramuscular (IM) dose into the deltoid muscle.

Mid dose of ARCT-2304, Schedule 1, Young Adults

Mid dose of ARCT-2304 administered through intramuscular injection in the deltoid muscle.

Interventions: 2-dose regimen, schedule 1 Investigational Vaccine: ARCT-2304

Group Type EXPERIMENTAL

ARCT-2304

Intervention Type BIOLOGICAL

Each participant will receive 2-dose regimen intramuscular (IM) dose into the deltoid muscle.

High dose of ARCT-2304, Schedule 1, Young Adults

High dose of ARCT-2304 administered through intramuscular injection in the deltoid muscle.

Interventions: 2-dose regimen, schedule 1 Investigational Vaccine: ARCT-2304

Group Type EXPERIMENTAL

ARCT-2304

Intervention Type BIOLOGICAL

Each participant will receive 2-dose regimen intramuscular (IM) dose into the deltoid muscle.

Control, Schedule 1, Young Adults

Control Vaccine (dose 1) and placebo (dose 2) administered through intramuscular injection in the deltoid muscle.

Interventions: 2-dose regimen, schedule 1 Investigational Vaccine: Comparator vaccine younger adult and saline placebo vaccine

Group Type ACTIVE_COMPARATOR

Control vaccine younger adults

Intervention Type BIOLOGICAL

Each participant will receive one intramuscular (IM) dose into the deltoid muscle.

Placebo Vaccine

Intervention Type OTHER

Each participant will receive one intramuscular (IM) dose into the deltoid muscle.

Low dose of ARCT-2304, Schedule 1, Older Adults

Low dose of ARCT-2304 administered through intramuscular injection in the deltoid muscle.

Interventions: 2-dose regimen, schedule 1 Investigational Vaccine: ARCT-2304

Group Type EXPERIMENTAL

ARCT-2304

Intervention Type BIOLOGICAL

Each participant will receive 2-dose regimen intramuscular (IM) dose into the deltoid muscle.

Mid dose of ARCT-2304, Schedule 1, Older Adults

Mid dose of ARCT-2304 administered through intramuscular injection in the deltoid muscle.

Interventions: 2-dose regimen, schedule 1 Investigational Vaccine: ARCT-2304

Group Type EXPERIMENTAL

ARCT-2304

Intervention Type BIOLOGICAL

Each participant will receive 2-dose regimen intramuscular (IM) dose into the deltoid muscle.

High dose of ARCT-2304, Schedule 1, Older Adults

High dose of ARCT-2304 administered through intramuscular injection in the deltoid muscle.

Interventions: 2-dose regimen, schedule 1 Investigational Vaccine: ARCT-2304

Group Type EXPERIMENTAL

ARCT-2304

Intervention Type BIOLOGICAL

Each participant will receive 2-dose regimen intramuscular (IM) dose into the deltoid muscle.

Control, Schedule 1, Older Adults

Older Adults Control Vaccine (dose 1) and placebo (dose 2) administered through intramuscular injection in the deltoid muscle.

Interventions: 2-dose regimen, schedule 1 Investigational Vaccine: Comparator vaccine older adult and saline

Group Type ACTIVE_COMPARATOR

Control vaccine older adults

Intervention Type BIOLOGICAL

Each participant will receive one intramuscular (IM) dose into the deltoid muscle.

Placebo Vaccine

Intervention Type OTHER

Each participant will receive one intramuscular (IM) dose into the deltoid muscle.

Low dose of ARCT-2304, Schedule 2, Young Adults

Low dose of ARCT-2304 administered through intramuscular injection in the deltoid muscle.

Interventions: 2-dose regimen, schedule 2 Investigational Vaccine: ARCT-2304

Group Type EXPERIMENTAL

ARCT-2304

Intervention Type BIOLOGICAL

Each participant will receive 2-dose regimen intramuscular (IM) dose into the deltoid muscle.

Mid dose of ARCT-2304, Schedule 2, Young Adults

Mid dose of ARCT-2304 administered through intramuscular injection in the deltoid muscle.

Interventions: 2-dose regimen, schedule 2 Investigational Vaccine: ARCT-2304

Group Type EXPERIMENTAL

ARCT-2304

Intervention Type BIOLOGICAL

Each participant will receive 2-dose regimen intramuscular (IM) dose into the deltoid muscle.

High dose of ARCT-2304, Schedule 2, Young Adults

High dose of ARCT-2304 administered through intramuscular injection in the deltoid muscle.

Interventions: 2-dose regimen, schedule 2 Investigational Vaccine: ARCT-2304

Group Type EXPERIMENTAL

ARCT-2304

Intervention Type BIOLOGICAL

Each participant will receive 2-dose regimen intramuscular (IM) dose into the deltoid muscle.

Control, Schedule 2, Young Adults

Young Adults Control Vaccine (dose 1) and placebo (dose 2) administered through intramuscular injection in the deltoid muscle.

Interventions: 2-dose regimen, schedule 2 Investigational Vaccine: Comparator vaccine younger adult and saline placebo vaccine

Group Type ACTIVE_COMPARATOR

Control vaccine younger adults

Intervention Type BIOLOGICAL

Each participant will receive one intramuscular (IM) dose into the deltoid muscle.

Placebo Vaccine

Intervention Type OTHER

Each participant will receive one intramuscular (IM) dose into the deltoid muscle.

Interventions

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ARCT-2304

Each participant will receive 2-dose regimen intramuscular (IM) dose into the deltoid muscle.

Intervention Type BIOLOGICAL

Control vaccine younger adults

Each participant will receive one intramuscular (IM) dose into the deltoid muscle.

Intervention Type BIOLOGICAL

Control vaccine older adults

Each participant will receive one intramuscular (IM) dose into the deltoid muscle.

Intervention Type BIOLOGICAL

Placebo Vaccine

Each participant will receive one intramuscular (IM) dose into the deltoid muscle.

Intervention Type OTHER

Other Intervention Names

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Self-Amplifying mRNA pandemic Influenza vaccine Influenza vaccine Influenza vaccine saline

Eligibility Criteria

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Inclusion Criteria

* Individuals are male or female adults 18-80 years of age.
* Healthy participants or participants with pre-existing stable medical conditions.
* Individuals of childbearing potential must be willing to adhere to contraceptive requirements.

Exclusion Criteria

* Individuals with acute medical conditions or febrile illness, including body temperature ≥100.4°F (≥38.0°C measured by any method) within 3 days prior to randomization.
* Individuals with a known history of severe hypersensitivity reactions, including anaphylaxis, or other significant adverse reactions to any mRNA vaccine, influenza vaccine, or excipients.
* Individuals with a history of myocarditis, pericarditis, myopericarditis, or cardiomyopathy.
* Individuals who received any influenza vaccine within 3 months prior to first vaccine administration or plan to receive an influenza vaccine during the study period.
* Individuals who have received mRNA vaccination within 60 days before the first vaccine administration.
* Individuals who have received or plan to receive an A/H5N1 influenza vaccine and/or individuals who had substantial exposure to or direct contact with poultry, wild birds, live cattle, or raw milk.
Minimum Eligible Age

18 Years

Maximum Eligible Age

80 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes

Sponsors

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Biomedical Advanced Research and Development Authority

FED

Sponsor Role collaborator

Arcturus Therapeutics, Inc.

INDUSTRY

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Principal Investigators

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Clinical Program Director

Role: STUDY_DIRECTOR

Arcturus Therapeutics

Locations

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Velocity Clinical Research

La Mesa, California, United States

Site Status

Velocity Clinical Research

San Bernardino, California, United States

Site Status

Tekton Research

Longmont, Colorado, United States

Site Status

CTI Clinical Research Center

Cincinnati, Ohio, United States

Site Status

Countries

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United States

Provided Documents

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Document Type: Informed Consent Form

View Document

Other Identifiers

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ARCT-2304-01

Identifier Type: -

Identifier Source: org_study_id

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