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Completed

NCT Number: NCT06602531

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

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)

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Key information

Conditions

Influenza, Human Infections Orthomyxoviridae Infections RNA Virus Infections Respiratory Tract Diseases Respiratory Tract Infections Virus Diseases

Age range

18 year–80 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 1

Primary location

Velocity Clinical Research, La Mesa, California, United States

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About this study

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

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Main 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.

Main 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.

Treatment and study plan

ARCT-2304

Biological

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

Other names: Self-Amplifying mRNA pandemic Influenza vaccine

Control vaccine (licensed seasonal influenza vaccine) younger adults

Biological

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

Other names: Influenza vaccine

Control vaccine (licensed seasonal influenza vaccine) older adults

Biological

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

Other names: Influenza vaccine

Placebo Vaccine

Other

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

Other names: saline

Primary outcomes

  1. Percentage of participants reporting local Adverse Events

    Time frame: For 7 days following each study vaccination

    Solicited local AEs including injection site pain, erythema, and swelling

  2. Percentage of participants reporting systemic Adverse Events

    Time frame: For 7 days following each study vaccination

    Solicited systemic AEs including fatigue, headache, myalgia, arthralgia, nausea, dizziness, chills, and fever

  3. Percentage of participants reporting unsolicited Adverse Events

    Time frame: For 28 days following each study vaccination

    Spontaneously reported adverse events and as elicited by investigational site staff

  4. Percentage of participants reporting laboratory or vital signs abnormalities

    Time frame: For 28 days following each study vaccination

    Abnormal clinically significant values

  5. Percentage of participants reporting serious adverse events, medically attended adverse events, adverse events of special interest, and adverse events leading to early termination

    Time frame: For 28 days following each study vaccination

    Spontaneously reported adverse events and as elicited by investigational site staff

  6. Serum hemagglutination inhibition (HAI) antibody levels against the HA glycoprotein

    Time frame: For 28 days following study second vaccination

    HAI antibody levels expressed as GMT, GMFRs, SCRs, and HAI titers

  7. Serum neuraminidase enzyme-linked lectin (ELLA) assay antibody levels against the NA glycoproteins

    Time frame: For 28 days following study second vaccination

    ELLA antibody levels expressed as GMT, GMFRs, SCRs, and HAI titers

Secondary outcomes

  1. Percentage of participants reporting serious adverse events, medically attended adverse events, adverse events of special interest, and adverse events leading to early termination

    Time frame: For 240 days following study vaccination

    Spontaneously reported adverse events and as elicited by investigational site staff

  2. Serum hemagglutination inhibition (HAI) antibody levels against the HA glycoprotein

    Time frame: For 240 days following study vaccination

    HAI antibody levels expressed as GMT, GMFRs, SCRs and HAI titers

  3. Serum neuraminidase enzyme-linked lectin (ELLA) assay antibody levels against the NA glycoproteins

    Time frame: For 240 days following study vaccination

    ELLA antibody levels expressed as GMT, GMFRs, SCRs and HAI titers

  4. Serum neutralizing (MN) antibody levels against the HA glycoprotein

    Time frame: For 28 days following study second vaccination

    MN antibody levels expressed as GMT, GMFRs, SCRs, and MN titers

Sponsors and collaborators

Lead sponsor

Arcturus Therapeutics, Inc.

Industry

Collaborators

  • Biomedical Advanced Research and Development Authority

Registry information

Official study title

A Phase 1, First-in-human, Randomized, Observer-blind, Parallel Design, Controlled, Dose Level and Schedule-finding Study to Evaluate the Safety, Reactogenicity, and Immunogenicity of a Self-Amplifying mRNA Pandemic Influenza Vaccine (ARCT-2304) When Administered to Healthy Adults

Important dates

Study start
2024
Primary completion
2025
Study completion
2025
First posted
Sep 19, 2024
Registry last updated
Apr 3, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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