A Study to Assess the Immune Response and Safety of a Vaccine Against Influenza in Adults 18 Years of Age and Older

NCT07121192
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Phase
Phase 2
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Recruitment status
Completed
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Participants
776
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Lead sponsor
GlaxoSmithKline
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Start date
2025-08-25
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Number of sites
22
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Summary
"The purpose of this study is to assess the reactogenicity, safety and immune response of GlaxoSmithKlines (GSK) messenger RNA (mRNA)-based multivalent seasonal influenza vaccine candidates administered in healthy younger and older adults."
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Short title
A Study to Assess the Immune Response and Safety of a Vaccine Against Influenza in Adults 18 Years of Age and Older
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Official title
A Phase 2a Randomized, Observer-Blind, Study to Evaluate the Immunogenicity and Safety of mRNA-Based Multivalent Seasonal Influenza Vaccine Candidates in Adults 18 Years of Age And Older
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Control arm
Active comparator
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Registry reports results
No
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Listing at source
Listed
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Recruitment status
Completed
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Phase
Phase 2
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Study type
Interventional
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Completion date
2026-05-11
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First posted
2025-08-13
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Registry last updated
2026-05-28
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Primary completion date
2026-05-11
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Start date
2025-08-25
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Actual participants
776
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Participants
776
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Participant count basis
Actual
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Protocol amendments
1
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Number of sites
22
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Data monitoring committee
No
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Registry sponsor category
Industry
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Lead sponsor
GlaxoSmithKline
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Source registry
ClinicalTrials.gov
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Registry ID
NCT07121192
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ClinicalTrials.gov ID
NCT07121192
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Registry record
Open registry record
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Allocation
Randomised
Model
Parallel groups
Purpose
Prevention
Masking
Quadruple masking
Masking description
This is an Observer-blind study.
Masked roles
Participants, Care providers, Investigators, Outcome assessors
Sources for study design
clinicaltrials.gov

  1. Geometric Mean Titer (GMT) Ratio of Antigen 1 Titer

    Timeframe: At Day 29

  2. Geometric Mean Increase (GMI) of Antigen 1 Titer

    Timeframe: From Day 1 to Day 29

  3. Percentage of Participants with Antigen 1 Seroconversion Rate (SCR)

    Timeframe: From Day 1 to Day 29

  4. Percentage of Participants with Antigen 1 Seroprotection Rate (SPR)

    Timeframe: At Day 1 and Day 29

  5. Number of Participants with Solicited Administration Site Adverse Events (Aes)

    Timeframe: From Day 1 to Day 7

    The solicited administration site AEs considered are pain, redness, swelling and lymphadenopathy.

  6. Number of Participants with Solicited Systemic Aes

    Timeframe: From Day 1 to Day 7

    The solicited systemic AEs considered are fever, headache, fatigue, myalgia, arthralgia and chills. Fever is defined as temperature greater than or equal to (\>=) 38 °C/100.4°F regardless the location of measurement.

  7. Number of Participants with Unsolicited Aes

    Timeframe: From Day 1 to Day 28

    An unsolicited AE is an AE that was either not included in the list of solicited events or could be included in the list of solicited events but with an onset outside the specified period of follow-up for solicited events.

  8. Number of Participants with Serious Adverse Events (SAEs)

    Timeframe: From Day 1 to Day 181 (study end)

    SAE is an AE which results in death, is life-threatening, requires inpatient hospitalization or prolongation of existing hospitalization, results in disability/incapacity, or other situations that are considered serious per medical or scientific judgment.

  9. Number of Participants with Adverse Events of Special Interest (AESIs)

    Timeframe: From Day 1 to Day 181 (study end)

  10. Number of Participants with Medically Attended Adverse Events (MAAEs)

    Timeframe: From Day 1 to Day 181 (study end)

    A MAAE is an AE for which the participant received medical attention including any symptom or illness requiring hospitalization, or an emergency room visit, or visit to/by a healthcare professional.

  11. Number of Participants with any Laboratory abnormalities

    Timeframe: From Day 1 to Day 29

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  1. GMT Ratio of Antigen 2 Titer

    Timeframe: At Day 29

  2. GMI of Antigen 2 Titer

    Timeframe: From Day 1 to Day 29

  3. Percentage of Participants with Antigen 2 SCR

    Timeframe: From Day 1 to Day 29

Sources for outcomes
clinicaltrials.gov

Sex
All
Age groups
Adults, Older adults
Minimum age
18 Years
Healthy volunteers
Yes

  1. Participants, who, in the opinion of the investigator, can and will comply with the requirements of the protocol (e.g., completion of the eDiary, attendance to study contacts and study site visits, and ability to access and utilize a phone or other electronic communications) independently or with the assistance of a caregiver.

  2. Written (physically, or digitally) informed consent obtained from the participant prior to performance of any study-specific procedure.

  3. A male or female at least 18 YOA at the time of the screening.

  4. Healthy participants or medically stable patients as established by medical history, and clinical examination. Participants with chronic medical conditions with or without specific treatment (e.g., chronic metabolic, cardiac, pulmonary, renal, neurologic, and hematologic diseases) are allowed to participate in this study, if considered by the investigator as medically stable. A stable medical condition is defined as disease not requiring significant change in therapy or hospitalization for worsening disease during 3 months before enrollment.

  5. Female participants of non-childbearing potential may be enrolled in the clinical study.

  6. Female participants of childbearing potential may be enrolled in the clinical study, if the participant:

    • Has practiced adequate contraception for at least 4 weeks prior to the study intervention administration, and
    • Has a negative urine pregnancy test within 24 hours prior to the study intervention administration, and
    • Has agreed to continue adequate contraception for at least 8 weeks after study intervention administration.

  7. Body mass index (BMI) between18 kg/m^² and 33kg/m^².

  1. Where applicable, FDA toxicity grades will be exclusionary.
  2. Immunosuppressive or immunodeficient conditions by history/exam; stable HIV-positive individuals on therapy can participate.
  3. History of Guillain-Barré Syndrome within 6 weeks of receiving any vaccine.
  4. Significant underlying illness that in the opinion of the investigator would be expected to prevent completion of the study (e.g., life-threatening disease likely to limit survival to less than 1 year).
  5. Hypersensitivity to latex.
  6. History of any reaction or hypersensitivity likely to be exacerbated by any component of the study intervention(s).
  7. History of hypersensitivity or severe allergic reaction to any previous influenza vaccine.
  8. History of hypersensitivity or severe allergic reaction to any previous mRNA vaccine.
  9. History of or current suspicion of myocarditis or pericarditis, or medical issues increasing such risks.
  10. Condition that in the judgment of the investigator would make intramuscular injection unsafe.
  11. Any other clinical condition that, in the opinion of the investigator, might pose additional risk to the participant due to participation in the clinical study.
  12. History of confirmed influenza infection by local health authority-approved testing methods within 180 days prior to study intervention administration.
  13. Use of any investigational or non-registered product (drug, vaccine or invasive medical device) other than the study intervention(s) during the period beginning 28 days before the dose of study intervention(s) (Day -28 to Day 1), or their planned use during the study period.
  14. Administration of an influenza vaccine within 180 days before the study intervention administration or planned administration prior to Visit 4 (Day 29) during the study.
  15. Administration of any non-live attenuated non-study vaccine in the period starting 14 days before the study intervention administration, or planned administration within 14 days after study intervention administration.
  16. Administration of any live attenuated and/or mRNA non-study non-influenza vaccine in the period starting 28 days before the study intervention administration, or planned administration within 28 days after study intervention administration.
  17. Chronic administration of immune-modifying drugs.
  18. Administration of immunoglobulins and/or any blood products or plasma derivatives during the period starting 90 days before the study intervention, or planned administration during the study period.
  19. Administration of anti-tumoral medication during the period starting 90 days before the study intervention or planned administration during the study period.
  20. Concurrently participating in another clinical study, at any time during the study period, in which the participant has been or will be exposed to an investigational or a non-investigational intervention.
  21. Any study personnel or their immediate dependents, family, or household members.
  22. Has a history of chronic alcohol consumption and/or drug abuse as deemed by the investigator to render the potential participant unable/unlikely to provide accurate safety reports or comply with study procedures.
  23. Participant is pregnant.
  24. Participant is breastfeeding or will (re)start breastfeeding during the study.
Sources for eligibility
clinicaltrials.gov

  • GSK Investigational SiteAnniston, United States
  • GSK Investigational SiteFair Oaks, United States
  • GSK Investigational SiteSan Diego, United States
  • GSK Investigational SiteSan Diego, United States
  • GSK Investigational SiteWalnut Creek, United States
  • GSK Investigational SiteHialeah, United States
  • GSK Investigational SiteJupiter, United States
  • GSK Investigational SiteMiami, United States
  • GSK Investigational SiteStockbridge, United States
  • GSK Investigational SiteValparaiso, United States
  • GSK Investigational SiteLenexa, United States
  • GSK Investigational SiteSpringfield, United States
  • GSK Investigational SiteCarson City, United States
  • GSK Investigational SiteRochester, United States
  • GSK Investigational SiteGreensboro, United States
  • GSK Investigational SiteCleveland, United States
  • GSK Investigational SiteNorth Charleston, United States
  • GSK Investigational SiteAustin, United States
  • GSK Investigational SiteDeSoto, United States
  • GSK Investigational SiteFort Worth, United States
  • GSK Investigational SiteNewport News, United States
  • GSK Investigational SiteSeattle, United States
Sources for sites
clinicaltrials.gov

  • 2025
  • 2025-522278-35
Sources for references
clinicaltrials.gov

Related records

Drugs (2)

Lead sponsors (1)

Conditions (1)