Study of Different Formulations of Vaccines Encoding the RSV Monovalent Antigen or the Flu H5 Antigen in Participants 18 to 49 Years of Age

NCT07516418
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Phase
Phase 1
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Recruitment status
Recruiting
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Participants
570
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Lead sponsor
Sanofi
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Start date
2026-04-15
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Number of sites
6
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Summary
The purpose of this study is to evaluate the safety and immunogenicity of different formulations of vaccines encoding the RSV monovalent antigen or the Flu hemagglutinin subtype 5 (H5) antigen in healthy participants aged 18 to 49 years. The total duration of study participation for each participant varies by stage and treatment arm. Stage 1: * For Arm 1, Arm 2, and Arm 3 the duration of study participation will be approximately 7 months for each participant. * For Arm 4, Arm 5, and Arm 6 the duration of study participation will be approximately 6 months for each participant. Stage 2: For all arms, the duration of study participation will be approximately 7 months for each participant.
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Short title
Study of Different Formulations of Vaccines Encoding the RSV Monovalent Antigen or the Flu H5 Antigen in Participants 18 to 49 Years of Age
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Official title
A Phase 1, Randomized, Multi-center Study to Evaluate the Safety and Immunogenicity of Different Formulations of Vaccines Encoding the RSV Monovalent Antigen or the Flu H5 Antigen in Healthy Participants 18 to 49 Years of Age
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Registry reports results
No
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Listing at source
Listed
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Recruitment status
Recruiting
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Phase
Phase 1
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Study type
Interventional
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Completion date
2027-04-04
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First posted
2026-04-08
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Registry last updated
2026-05-08
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Primary completion date
2027-04-04
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Start date
2026-04-15
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Participants
570
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Participant count basis
Estimated
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Planned participants
570
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Protocol amendments
0
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Number of sites
6
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Data monitoring committee
No
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Registry sponsor category
Industry
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Lead sponsor
Sanofi
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Source registry
ClinicalTrials.gov
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Registry ID
NCT07516418
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ClinicalTrials.gov ID
NCT07516418
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Registry record
Open registry record
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Allocation
Randomised
Model
Sequential
Purpose
Prevention
Masking
Triple masking
Masking description
Modified double-blind design for Sentinel and Main Cohorts. * Blinded to formulation: Participants; Investigators; Sponsor study staff (except biostatistician); Sponsor laboratory personnel (during interim analysis); Sponsor SMT for Main Cohorts only * Unblinded to formulation: Staff preparing and administering study vaccines (at group level); Study biostatistician (throughout study); Sponsor SMT for Sentinel Cohorts, including ESDRs; SMT may receive unblinded data in case of identified safety concern evaluate the potential safety signal. * Blinded to antigen assignment (RSV vs. Flu H5): None * Unblinded to antigen assignment (RSV vs. Flu H5): Investigators; Participants; Sponsor study staff; Sponsor laboratory personnel (for immunogenicity assays); Study biostatistician; SMT
Masked roles
Participants, Care providers, Investigators
Sources for study design
clinicaltrials.gov

  1. Presence of any unsolicited systemic Adverse Events (AEs) reported within 30 minutes after vaccination

    Timeframe: On Day 1

  2. Presence of solicited injection site reactions (ie, injection site pain, injection site erythema, injection site swelling, pre-listed in participant's diary and in the eCRF (electronic case report form)) occurring through 7 days after each vaccination

    Timeframe: Day 1 through day 8

  3. Presence of solicited systemic reactions (ie, fever, headache, and only new or worsened fatigue, myalgia, arthralgia, and chills pre-listed in the participant's diary and in the eCRF) occurring through 7 days after each vaccination

    Timeframe: Day 1 through day 8

  4. Presence of unsolicited AEs reported through 20 days after the first vaccination and after the second vaccination for IMPs with the Flu H5 antigen

    Timeframe: Day 1 through day 21

  5. Presence of unsolicited AEs reported through 28 days after vaccination for IMPs with the RSV antigen

    Timeframe: Day 1 through day 29

  6. Presence of SAEs (Serious Adverse Events) and AESIs (Adverse Events of Special Interest) throughout the study (ie, through 6 months after vaccination)

    Timeframe: SAE: Screening day through day 202 (IMPs containing Flu H5 antigen), Screening day through day 181 (IMPs containing RSV antigen); AESI: Day 1 through day 202 (IMPs containing Flu H5 antigen), Day 1 through day 181 (IMPs containing RSV antigen)

  7. Presence of out-of-range biological test results (including shift from baseline values) through 7 days after each vaccination

    Timeframe: Screening through day 8

  8. Presence of AEs leading to study discontinuation throughout the study (ie, through 6 months after vaccination)

    Timeframe: Screening through day 202 (IMPs containing Flu H5 antigen), Screening through day 181 (IMPs containing RSV antigen)

  9. RSV A and RSV B serum nAb (neutralizing antibodies) titers at pre-vaccination and 28 days post-vaccination in all participants receiving IMPs with the RSV antigen

    Timeframe: Day 1 and day 29

  10. Flu H5 antibody (Ab) titer measured by hemagglutination inhibition (HAI) at pre-vaccination and 21 and 42 days post-vaccination in all participants receiving IMPs with the Flu H5 antigen

    Timeframe: Day 1, day 22 and day 43

  11. Hemagglutination Inhibition (HAI) geometric mean titer ratio at 21 and 42 days post-vaccination relative to pre-vaccination for all participants receiving IMPs with the Flu H5 antigen

    Timeframe: Day 1, day 22 and day 43

    Ratio of post-vaccination to pre-vaccination hemagglutination inhibition (HAI) antibody titers, calculated as Day 22/Day 1 and Day 43/Day 1.

  12. Seroconversion rate based on Hemagglutination inhibition (HAI) antibody titers at pre-vaccination and 21 and 42 days post-vaccination in all participants receiving IMPs with the Flu H5 antigen

    Timeframe: Day 1, day 22 and day 43

  13. Proportion of participants with Hemagglutination Inhibition (HAI) antibody titer ≥40 at pre-vaccination and 21 and 42 days post-vaccination in all participants receiving IMPs with the Flu H5 antigen

    Timeframe: Day 1, day 22, and day 43

  14. Proportion of participants with detectable HAI antibody titer ≥10 at pre-vaccination and 21 and 42 days post-vaccination in all participants receiving IMPs with the Flu H5 antigen

    Timeframe: Day 1, day 22, and day 43

  1. Geometric mean neutralizing antibody titers measured by Neutralization Assay (NT) at pre-vaccination and 21 and 42 days post-vaccination in all participants receiving IMPs with the Flu H5 antigen

    Timeframe: Day 1, day 22, and day 43

  2. Neutralizing antibody titer ratio at pre-vaccination and 21 and 42 days post-vaccination in all participants receiving IMPs with the Flu H5 antigen

    Timeframe: Day 1, day 22, and day 43

    Ratio of post-vaccination to pre-vaccination neutralizing antibody titers, calculated as Day 22/Day 1 and Day 43/Day 1 using a validated neutralization (NT) assay.

  3. Proportion of participants with neutralizing antibody titers ≥20, ≥40, and ≥80 at pre-vaccination and 21 and 42 days post-vaccination in all participants receiving IMPs with the Flu H5 antigen

    Timeframe: Day 1, day 22, and day 43

  4. Proportion of participants with detectable neutralizing antibody titers ≥10 at pre-vaccination and 21 and 42 days post-vaccination in all participants receiving IMPs with the Flu H5 antigen

    Timeframe: Day 1, day 22, and day 43

  5. Proportion of participants with ≥2-fold and ≥4-fold increase in neutralizing antibody titers at pre-vaccination and 21 and 42 days post-vaccination in all participants receiving IMPs with the Flu H5 antigen

    Timeframe: Day 1, day 22, and day 43

Sources for outcomes
clinicaltrials.gov

Sex
All
Age groups
Adults
Minimum age
18 Years
Maximum age
49 Years
Healthy volunteers
Yes

  • Aged 18 to 49 years on the day of inclusion
  • A female participant is eligible to participate if she is not pregnant or breastfeeding and of the following conditions applies:
  • Is of NCBP (Non-Child-Bearing Potential). To be considered of NCBP, a female must be post-menopausal for at least 1 year, or surgically sterile. OR
  • Is of CBP (Child-Bearing Potential) and uses an effective contraceptive method or abstinence from at least 4 weeks prior to study intervention administration until at least 12 weeks after the last study intervention administration.

• Any condition which, in the opinion of the Investigator, might interfere with the evaluation of the study objectives

The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.

Sources for eligibility
clinicaltrials.gov

  • Site # 0361002Griffith, AustraliaRecruiting
  • Site # 0361001Herston, AustraliaRecruiting
  • Site # 0361003Morayfield, AustraliaRecruiting
  • Site # 0361005Sippy Downs, AustraliaRecruiting
  • Site # 03610004South Brisbane, AustraliaRecruiting
  • Site # 036006Taringa, AustraliaRecruiting
Sources for sites
clinicaltrials.gov

Other registry identifiers

  • U1111-1322-6386
Sources for references
clinicaltrials.gov

Related records

Drugs (1)

Lead sponsors (1)

Conditions (3)

Targets (1)