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Immunogenicity and Safety Study of Self-amplifying MRNA COVID-19 Vaccine Administered with Influenza Vaccines in Adults

Phase 3
Completed
Conditions
COVID-19
Interventions
Biological: ARCT-2303
Biological: Influenza vaccine, adjuvanted
Biological: Influenza vaccine
Other: Placebo
Registration Number
NCT06279871
Lead Sponsor
Arcturus Therapeutics, Inc.
Brief Summary

This is a multicenter, observer-blind, randomized, controlled phase 3 study to evaluate the immunogenicity, reactogenicity, and safety of an investigational self-amplifying RNA COVID-19 vaccine (ARCT-2303) administered concomitantly with quadrivalent influenza vaccines or standalone in adults who previously received authorized COVID-19 vaccine.

Detailed Description

Approximately 1680 participants previously vaccinated with authorized COVID-19 vaccine will be enrolled in this study in two age cohorts (younger adults and older adults). Within each cohort, participants will be randomly assigned in a ratio of 1:1:1 to receive the ARCT-2303 vaccine concomitantly with a quadrivalent influenza vaccine, the ARCT-2303 vaccine and placebo, or the quadrivalent influenza vaccine and placebo. The assessment of immunogenicity will be performed 28 days after vaccination. To provide equal benefit from the participation in the study and complete seasonal vaccination against COVID-19 and influenza, a switchover vaccine dose (influenza, ARCT-2303 or placebo) will be administered 28 days after initial vaccination. All participants will be followed up for safety assessment until the end of the study.

A historical control group vaccinated on a similar schedule (ARCT-154 vaccine) from a previous study (ARCT-154-J01) will be used to compare with the immunogenicity of the ARCT-2303 vaccine.

Cohort A (younger adults; approximately 1200 participants):

* Group 1a (ARCT-2303/Influenza vaccine): participants will receive one dose of ARCT-2303 and one dose of Influenza vaccine (opposite arms) on Day 1, and one dose of placebo on Day 29.

* Group 2a (ARCT-2303): participants will receive one dose of ARCT-2303 and one dose of placebo (opposite arms) on Day 1, and one dose of Influenza vaccine on Day 29.

* Group 3a (Influenza vaccine): participants will receive one dose of Influenza vaccine and one dose of placebo (opposite arms) on Day 1, and one dose of ARCT-2303 on Day 29.

Cohort B (older adults; approximately 480 participants):

* Group 1b (ARCT-2303/Influenza vaccine): participants will receive one dose of ARCT-2303 and one dose of Influenza vaccine (opposite arms) on Day 1, and one dose of placebo on Day 29.

* Group 2b (ARCT-2303): participants will receive one dose of ARCT-2303 and one dose of placebo (opposite arms) on Day 1, and one dose of Influenza vaccine on Day 29.

* Group 3b (Influenza vaccine): participants will receive one dose of Influenza vaccine and one dose of placebo (opposite arms) on Day 1, and one dose of ARCT-2303 on Day 29.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
1499
Inclusion Criteria

1, Individuals are male, female, or transgender adults ≥18 years of age.

  1. Healthy participants or participants with pre-existing stable medical conditions.

  2. Participant or legally authorized representatives must freely provide documented informed consent prior to study procedures being performed.

  3. Individuals must have been previously vaccinated with COVID-19 vaccines.

  4. Individuals of childbearing potential must be willing to adhere to contraceptive requirements.

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Exclusion Criteria
  1. Individuals with acute medical illness or febrile illness.
  2. Individuals with a positive SARS-CoV-2 rapid antigen test at Screening.
  3. Individuals with a history of COVID-19 or virologically confirmed SARS-CoV-2 infection within the past 5 months or history of COVID-19 with ongoing sequelae.
  4. Individuals with a known history of severe hypersensitivity reactions, including anaphylaxis, or other significant adverse reactions to any components of mRNA vaccine, or influenza vaccine, including egg protein.
  5. Individuals who have a positive pregnancy test at the Screening visit or who intend to become pregnant or breastfeed during the study.
  6. Individuals with a history of myocarditis, pericarditis, myopericarditis or cardiomyopathy.
  7. Individuals with a history of Guillain-Barré syndrome, encephalomyelitis, or transverse myelitis.
  8. Individuals with a history of congenital or acquired immunodeficiency.
  9. Individuals who have received immunomodulatory, immunostimulatory, or immunosuppressant drugs within 3 months of Screening; or individuals requiring systemic corticosteroids exceeding 10 mg/day of prednisone equivalent for ≥10 days within 30 days of Screening.
  10. Individuals who have received immunoglobulins and/or any blood or blood products within the 3 months before the first vaccine administration or plan to receive such products at any time during the study.
  11. Individuals with a documented history of HIV infection, or who are currently known to have active tuberculosis.
  12. Individuals receiving treatment with another investigational drug, biological agent, or device.
  13. Individuals who have received any investigational COVID-19 vaccines.
  14. Individuals who received any influenza vaccine within 6 months prior to enrollment or plan to receive an influenza vaccine during the study period.
  15. Individuals who have received any other licensed vaccines within 14 days prior to enrollment in this study or who are planning to receive any vaccine up to 14 days after the study vaccination.
  16. Individuals who are investigator site staff members, employees of the Sponsor or the Clinical Research Organization directly involved in the conduct of the study, or site staff members otherwise supervised by the investigator or immediate family members of any of the previously mentioned individuals.
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Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Group 1b (ARCT-2303/ Influenza vaccine)Influenza vaccine, adjuvantedParticipants will receive one 0.5-mL IM dose of ARCT-2303 and one 0.5-mL IM dose of influenza vaccine on Day 1 followed by a 0.5-mL IM dose of placebo on Day 29.
Group 3a (Influenza vaccine)PlaceboParticipants will receive one 0.5-mL IM dose of influenza vaccine and one 0.5-mL IM dose of placebo on Day 1 followed by a 0.5-mL IM dose of ARCT-2303 on Day 29.
Group 1a (ARCT-2303/Influenza vaccine)ARCT-2303Participants will receive one 0.5-mL IM (intramuscular) dose of ARCT-2303 and one 0.5-mL IM dose of influenza vaccine on Day 1 followed by a 0.5-mL IM dose of placebo on Day 29.
Group 2a (ARCT-2303)Influenza vaccineParticipants will receive one 0.5-mL IM dose of ARCT-2303 and one 0.5-mL IM dose of placebo on Day 1 followed by a 0.5-mL IM dose of influenza vaccine on Day 29.
Group 3b (Influenza vaccine)Influenza vaccine, adjuvantedParticipants will receive one 0.5-mL IM dose of influenza vaccine and one 0.5-mL IM dose of placebo on Day 1 followed by a 0.5-mL IM dose of ARCT-2303 on Day 29.
Group 3b (Influenza vaccine)PlaceboParticipants will receive one 0.5-mL IM dose of influenza vaccine and one 0.5-mL IM dose of placebo on Day 1 followed by a 0.5-mL IM dose of ARCT-2303 on Day 29.
Group 2a (ARCT-2303)ARCT-2303Participants will receive one 0.5-mL IM dose of ARCT-2303 and one 0.5-mL IM dose of placebo on Day 1 followed by a 0.5-mL IM dose of influenza vaccine on Day 29.
Group 2a (ARCT-2303)PlaceboParticipants will receive one 0.5-mL IM dose of ARCT-2303 and one 0.5-mL IM dose of placebo on Day 1 followed by a 0.5-mL IM dose of influenza vaccine on Day 29.
Group 2b (ARCT-2303)PlaceboParticipants will receive one 0.5-mL IM dose of ARCT-2303 and one 0.5-mL IM dose of placebo on Day 1 followed by a 0.5-mL IM dose of influenza vaccine on Day 29.
Group 3b (Influenza vaccine)ARCT-2303Participants will receive one 0.5-mL IM dose of influenza vaccine and one 0.5-mL IM dose of placebo on Day 1 followed by a 0.5-mL IM dose of ARCT-2303 on Day 29.
Group 1b (ARCT-2303/ Influenza vaccine)PlaceboParticipants will receive one 0.5-mL IM dose of ARCT-2303 and one 0.5-mL IM dose of influenza vaccine on Day 1 followed by a 0.5-mL IM dose of placebo on Day 29.
Group 2b (ARCT-2303)ARCT-2303Participants will receive one 0.5-mL IM dose of ARCT-2303 and one 0.5-mL IM dose of placebo on Day 1 followed by a 0.5-mL IM dose of influenza vaccine on Day 29.
Group 3a (Influenza vaccine)Influenza vaccineParticipants will receive one 0.5-mL IM dose of influenza vaccine and one 0.5-mL IM dose of placebo on Day 1 followed by a 0.5-mL IM dose of ARCT-2303 on Day 29.
Group 1a (ARCT-2303/Influenza vaccine)Influenza vaccineParticipants will receive one 0.5-mL IM (intramuscular) dose of ARCT-2303 and one 0.5-mL IM dose of influenza vaccine on Day 1 followed by a 0.5-mL IM dose of placebo on Day 29.
Group 1a (ARCT-2303/Influenza vaccine)PlaceboParticipants will receive one 0.5-mL IM (intramuscular) dose of ARCT-2303 and one 0.5-mL IM dose of influenza vaccine on Day 1 followed by a 0.5-mL IM dose of placebo on Day 29.
Group 3a (Influenza vaccine)ARCT-2303Participants will receive one 0.5-mL IM dose of influenza vaccine and one 0.5-mL IM dose of placebo on Day 1 followed by a 0.5-mL IM dose of ARCT-2303 on Day 29.
Group 1b (ARCT-2303/ Influenza vaccine)ARCT-2303Participants will receive one 0.5-mL IM dose of ARCT-2303 and one 0.5-mL IM dose of influenza vaccine on Day 1 followed by a 0.5-mL IM dose of placebo on Day 29.
Group 2b (ARCT-2303)Influenza vaccine, adjuvantedParticipants will receive one 0.5-mL IM dose of ARCT-2303 and one 0.5-mL IM dose of placebo on Day 1 followed by a 0.5-mL IM dose of influenza vaccine on Day 29.
Primary Outcome Measures
NameTimeMethod
SARS-CoV-2 neutralizing antibody titersDay 29

Immune response as measured by GMTs of neutralizing antibodies against Omicron XBB.1.5 subvariant (Group 1a; Group 2a)

SARS-CoV-2 neutralizing antibody seroconversion ratesDay 29

Immune response as measured by SARS-CoV-2 neutralizing antibody seroconversion rates against Omicron XBB.1.5 subvariant (Groups 2a and 2b; a comparator group from a previous study)

Hemagglutination Inhibition (HI) titersDay 1, Day 29

Immune response as measured by GMTs against influenza vaccine strains (Group 1a; Group 3a)

Secondary Outcome Measures
NameTimeMethod
SARS-CoV-2 neutralizing antibody titersDay 29

GMTs of SARS-CoV-2 neutralizing antibody titers against Omicron XBB.1.5 subvariant (Groups 2a and 2b; a comparator group from a previous study)

SARS-CoV-2 neutralizing antibody responsesDay 181

SARS-CoV-2 neutralizing antibody responses against Omicron XBB.1.5 subvariant as measured by GMT, Geometric Mean Fold Rise (post/pre-vaccination), proportion of participants with seroconversion and proportion of participants with antibody titer ≥ LLOQ (Group 1b; Group 2b)

Hemagglutination Inhibition (HI) assay titersDay 29

HI assay titers against influenza vaccine strains as measured by GMT, Geometric Mean Fold Rise (post/pre-vaccination), proportion of participants with seroconversion and proportion of participants with HI titers ≥1:40 (Group 1b; Group 3b)

SAE, Medically Attended Adverse Events (MAAE), Adverse Events of Special Interest (AESI), and AE leading to early terminationDay 1 to Day 181

Proportion of participants with SAE/MAAE/AESI/AE leading to early termination from study

SARS-CoV-2 neutralizing antibody seroconversion ratesDay 29

SARS-CoV-2 neutralizing antibody seroconversion rates against Omicron XBB.1.5 subvariant (Groups 2a and 2b; a comparator group from a previous study)

SARS-CoV-2 neutralizing antibody response (Group 1a; Group 2a)Days 1, 29 and 181

SARS-CoV-2 neutralizing antibody responses against Omicron XBB.1.5 subvariant as measured by GMT, Geometric Mean Fold Rise (post/pre-vaccination), proportion of participants with seroconversion and proportion of participants with antibody titer ≥ lower limit of quantitation (LLOQ) (Group 1a; Group 2a)

Hemagglutination Inhibition (HI) titersDay 1, Day 29

HI assay titers against influenza vaccine strains as measured by GMT, Geometric Mean Fold Rise (post/pre-vaccination), proportion of participants with seroconversion and proportion of participants with HI titers ≥1:40 (Group 1a; Group 3a)

Local and systemic adverse events (AEs)Day 1 to Day 8 after each vaccination

Proportion of participants with local and systemic solicited AEs

Unsolicited AEsDay 1 to Day 29 after each vaccination

Proportion of participants with unsolicited AEs

Trial Locations

Locations (29)

Paratus Clinical Central Coast

🇦🇺

Central Coast, New South Wales, Australia

Australian Clinical Research Network (ACRN)

🇦🇺

Sydney, New South Wales, Australia

Emeritus Research Sydney

🇦🇺

Sydney, New South Wales, Australia

Northern Beaches Clinical Research - Walski

🇦🇺

Sydney, New South Wales, Australia

USC Morayfield

🇦🇺

Morayfield, Queensland, Australia

USC Southbank

🇦🇺

Brisbane, Queensland, Australia

Emeritus Research Melbourne

🇦🇺

Melbourne, Victoria, Australia

The Peter Doherty Institute for Infection and Immunity

🇦🇺

Melbourne, Victoria, Australia

Tropical Disease Foundation - Putatan Health Center

🇵🇭

Muntinlupa City, Philippines

Sutherland Shire Clinical Research - Walski

🇦🇺

Miranda, New South Wales, Australia

Paratus Clinical Blacktown

🇦🇺

Sydney, New South Wales, Australia

Griffith University Clinical Trials Unit

🇦🇺

Sydney, New South Wales, Australia

Nucleus Network Brisbane (Q-Pharm)

🇦🇺

Brisbane, Queensland, Australia

Paratus Clinical Brisbane

🇦🇺

Brisbane, Queensland, Australia

Austrials -Sunshine

🇦🇺

Melbourne, Victoria, Australia

USC Sippy Down

🇦🇺

Sunshine Coast, Queensland, Australia

Nucleus Network

🇦🇺

Melbourne, Victoria, Australia

Veritus Research

🇦🇺

Melbourne, Victoria, Australia

Clinitrials - Mount Site

🇦🇺

Perth, Western Australia, Australia

Deposito de Medicamentos de Investigación Cousin Agustín (DEMEDICA)

🇭🇳

San Pedro Sula, Honduras

Far Eastern University - Nicanor R. M Foundation

🇵🇭

Quezon City, Philippines

CMAX

🇦🇺

Adelaide, South Australia, Australia

Wollongong Clinical Research

🇦🇺

Wollongong, New South Wales, Australia

Austrials - St. Leonards

🇦🇺

Sydney, New South Wales, Australia

IICIMED

🇨🇷

San Jose, Costa Rica

Paratus Clinical Canberra

🇦🇺

Canberra, Australian Capital Territory, Australia

Clínica San Agustín

🇨🇷

San José, Costa Rica

Organización y centro de investigación clínica Ochoa (OCINCO)

🇭🇳

Comayagua, Honduras

Inversiones en Investigación Médica S.A (INVERIME)

🇭🇳

Tegucigalpa, Honduras

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