A Study on the Immune Response and Safety of Vaccine Against Respiratory Syncytial Virus (RSV) Given to Adults 18 to 49 Years of Age at Increased Risk for Respiratory Syncytial Virus Disease, Compared to Older Adults 60 Years of Age and Above

Recruitment Status
COMPLETED - HAS RESULTS
(See Contacts and Locations)Verified August 2025 by GlaxoSmithKline
Sponsor
GlaxoSmithKline
Information Provided by (Responsible Party)
GlaxoSmithKline
Clinicaltrials.gov Identifier
NCT06389487
Other Study ID Numbers:
222253
First Submitted
April 23, 2024
First Posted
April 28, 2024
Results First Posted
July 27, 2025
Last Update Posted
September 24, 2025
Last Verified
August 2025

ClinicalTrials.gov processed this data on September 2025. Link to the current ClinicalTrials.gov record .

History of Changes

Study Details

Study Description

Condition or DiseaseIntervention/Treatment
Respiratory Syncytial Virus Infections
Biological: RSVPreF3 OA investigational vaccineBiological: RSVPreF3 OA investigational vaccineBiological: RSVPreF3 OA investigational vaccine

Study Design

Study TypeInterventional
Actual Enrollment1459 participants
Design AllocationNon-Randomized
Interventional ModelParallel Assignment
MaskingNone (Open Label)
Primary PurposePrevention
Official TitleA Phase 3b, Open-label Study to Evaluate the Non-inferiority of the Immune Response and to Evaluate the Safety of the RSVPreF3 OA Investigational Vaccine in Adults 18-49 Years of Age at Increased Risk for Respiratory Syncytial Virus Disease, Compared to Older Adults >=60 Years of Age
Study Start DateApril 28, 2024
Actual Primary Completion DateJuly 28, 2024
Actual Study Completion DateMarch 17, 2025

Groups and Cohorts

Group/CohortIntervention/Treatment
Part A: RSV-A-AIR Group
Adult (A) participants, 18-49 YOA, at increased risk (AIR) for RSV disease, received a single dose of RSVPreF3 OA investigational vaccine at Day 1. Participants in this group were considered for all study analyses, as per protocol.
Biological: RSVPreF3 OA investigational vaccine
1 dose of RSVPreF3 OA investigational vaccine is administered intramuscularly on Day 1.
Part A: RSV-OA Group
Older adults (OA) participants, ≥60 YOA, received a single dose of RSVPreF3 OA investigational vaccine at Day 1.
Biological: RSVPreF3 OA investigational vaccine
1 dose of RSVPreF3 OA investigational vaccine is administered intramuscularly on Day 1.
Part B: RSV-A-AIR Group
Adult participants, 18-49 YOA, AIR for RSV disease, received a single dose of RSVPreF3 OA investigational vaccine at Day 1. Participants in this group were considered only for Participant flow, Baseline Characteristics and all safety analyses, as per protocol.
Biological: RSVPreF3 OA investigational vaccine
1 dose of RSVPreF3 OA investigational vaccine is administered intramuscularly on Day 1.

Outcome Measures

Primary Outcome Measures
  1. Part A: RSV-A Neutralizing Titers Expressed as Group Geometric Mean Titers (GMTs)
    RSV-A neutralizing titers are given as group GMTs and are expressed as Estimated dilution 60 (ED60)
  2. Part A: Percentage of Participants With Seroresponse Rate (SRR) in RSV-A Neutralizing Titers
    SRR is defined as the percentage of participants having a fold increase in neutralizing titers (1 month post-study intervention administration over pre-study intervention administration) ≥4. RSV-A neutralizing titers are expressed as ED60.
  3. Part A: RSV-B Neutralizing Titers Expressed as Group GMTs
    RSV-B neutralizing titers are given as group GMTs and are expressed as ED60.
  4. Part A: Percentage of Participants With SRR in RSV-B Neutralizing Titers
    SRR is defined as the percentage of participants having a fold increase in neutralizing titers (1-month post-study intervention administration over pre-study intervention administration) ≥ 4. RSV-B neutralizing titers are expressed as ED60.
Secondary Outcome Measures
  1. Part A and B: Number of Participants Reporting Any Solicited Administration Site Events
    Assessed solicited administration site events were pain, redness (erythema) and swelling at administration site. Any = occurrence of the symptom regardless of intensity grade.
  2. Part A and B: Number of Participants Reporting Any Solicited Systemic Events
    Assessed solicited systemic events were fever (pyrexia), headache, myalgia (muscle pain), arthralgia (joint pain) and fatigue (tiredness). Fever was defined as temperature ≥38.0 degrees Celsius (°C), regardless of the location of measurement. The route for measuring temperature could be oral or axillary. Any = occurrence of the symptom regardless of intensity grade.
  3. Part A and B: Number of Participants Reporting Unsolicited Adverse Events (AEs)
    An unsolicited AE wass 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. Unsolicited AEs included both serious and non-serious AEs.
  4. Part A and B: Number of Participants Reporting Any Serious Adverse Events (SAEs), Related SAEs and Fatal SAEs
    An SAE is any untoward medical occurrence that results in death, is life-threatening, requires hospitalization or prolongation of existing hospitalization, results in disability/incapacity, is a congenital anomaly/birth defect in the offspring of a study participant, is considered or defined as an important medical event, or abnormal pregnancy outcomes. Any SAE = occurrence of the SAE regardless of the intensity grade or relation to study vaccination. Related SAE = SAE assessed by the investigator as related to the study vaccination. Fatal SAE = occurrence of a fatal SAE regardless of relation to study vaccination.
  5. Part A and B: Number of Participants Reporting Any Adverse Events of Special Interest (AESIs)
    AESIs assessed were potential immune-mediated diseases (pIMDs) and atrial fibrillation (AF). pIMDs were a subset of AESIs that included autoimmune diseases and other inflammatory and/or neurologic disorders of interest which may or may not have an autoimmune etiology. AEs of AF were considered as AESI.
  6. Part A: RSV-A Neutralizing Titers Expressed as GMTs
    RSV-A neutralizing titers are given as GMTs and are expressed as ED60.
  7. Part A: RSV-B Neutralizing Titers Expressed as GMTs
    RSV-B neutralizing titers are given as GMTs and are expressed as ED60.

Eligibility Criteria

Ages Eligible for Study(Adult, Older Adult)
Sexes Eligible for StudyAll
Accepts Healthy VolunteersYes
Inclusion Criteria
Participants and/or participant's parent(s)/ Legally acceptable representative (LAR) who, in the opinion of the investigator, can and will comply with the requirements of the protocol (e.g., completion of the eDiary, attend study site visits, ability to access and utilize a phone or other electronic communications).
Written or witnessed informed consent obtained from the participant/participant's parent(s)/LAR(s) (participant must be able to understand the informed consent) prior to performance of any study-specific procedure. Written informed assent obtained from the participant (participant must be able to understand the informed assent) if he/she is less than the legal age prior to performance of any study-specific procedure. Specific inclusion criteria for all participants in Cohort 1 and Cohort 3 (RSV-A-AIR Group) • A male or female participant 18-49 YOA at the time of the study intervention administration.
Participants should be diagnosed with at least 1 of the following medical conditions if considered medically stable by the investigator:
Chronic cardiopulmonary disease resulting in activity restricting symptoms or use of long term medication: o Chronic obstructive pulmonary disease (COPD) o Asthma o Cystic fibrosis o Other chronic respiratory diseases: lung fibrosis, restrictive lung disease, interstitial lung disease, emphysema or bronchiectasis o Chronic heart failure: o Pre-existing Coronary Artery Disease (CAD) (CAD not otherwise specified)
Cardiac arrhythmia
Diabetes mellitus: types 1 or 2 with active treatment for the past 6 months
Other diseases at increased risk for RSV disease:
Chronic kidney disease
Chronic moderate to severe liver disease
Neurologic or neuromuscular conditions
Female participants of non-childbearing potential may be enrolled in the study. Non-childbearing potential is defined as premenarche, hysterectomy, bilateral oophorectomy, bilateral salpingectomy or post-menopause.
Female participants of childbearing potential may be enrolled in the study, if the participant:
has practiced adequate contraception from 1 month prior to study intervention administration, and
has a negative pregnancy test on the day of study prior to intervention administration, and
has agreed to continue adequate contraception for at least 1 month after completion of the study intervention administration. Specific inclusion criteria for all participants in Cohort 2 (RSV-OA Group): • A male or female participant \>=60 YOA at the time of the study intervention administration. Participants with chronic stable medical conditions with or without specific treatment, such as diabetes, hypertension or cardiac disease are allowed to participate in this study if considered medically stable by the investigator. • Participants living in the general community or in an assisted-living facility that provides minimal assistance, such that the participant is primarily responsible for self-care and activities of daily living.
Exclusion Criteria
Medical conditions
Any confirmed or suspected immunosuppressive or immunodeficient condition resulting from disease (e.g., current malignancy, human immunodeficiency virus) or immunosuppressive/cytotoxic therapy (e.g., medication used during cancer chemotherapy, organ transplantation, or to treat autoimmune disorders), based on medical history and physical examination (no laboratory testing required).
History of any reaction or hypersensitivity likely to be exacerbated by any component of the study intervention.
Unstable chronic illness.
Any history of dementia or any medical condition that moderately or severely impairs cognition.
Recurrent or uncontrolled neurological disorders or seizures. Participants with medically controlled active or chronic neurological diseases can be enrolled in the study as per investigator assessment, provided that their condition will allow them to comply with the requirements of the protocol (e.g., completion of the diary cards, attend study site visits). Study participants may decide to assign a caregiver to help them complete the study procedures.
Significant underlying illness that in the opinion of the investigator would be expected to prevent completion of the study (e.g., life-threatening disease).
Any medical condition that in the judgment of the investigator would make intramuscular injection unsafe.
Any other clinical condition that, in the opinion of the investigator, might pose additional risk to the participant due to participation in the study. Prior/Concomitant therapy
Use of any investigational or non-registered product (drug, vaccine, or medical device) other than the study intervention during the period beginning 30 days before the dose of study intervention (Day -29 to Day 1), or planned use during the study period (up to Visit 3, Month 6).
Planned or actual administration of a vaccine not foreseen by the study protocol in the period starting 30 days before and ending 30 days after the dose of study intervention administration, with the exception of inactivated, subunit and split influenza vaccines or COVID-19 vaccines which can be administered up to 14 days before or from 14 days after the study intervention administration.
Previous vaccination with any RSV vaccine, including investigational RSV vaccines.
Chronic administration of immune-modifying drugs (defined as more than 14 consecutive days in total) and/or administration of long-acting immune-modifying treatments or planned administration at any time up to the End-of-study (EOS).
Up to 3 months prior to the study intervention administration:
For corticosteroids, this will mean prednisone \>=20 mg/day, or equivalent. Inhaled, topical and intra-articular steroids are allowed
Administration of immunoglobulins and/or any blood products or plasma derivatives
Up to 6 months prior to study intervention administration: long-acting immune-modifying drugs including among others immunotherapy (e.g., Tumor Necrosis Factor (TNF)-inhibitors), monoclonal antibodies, antitumoral medication. Prior/Concurrent clinical study experience • 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 vaccine/product (drug or invasive medical device). Other exclusions: Other exclusions for all participants:
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.
Bedridden participants.
Planned move during the study period that will prohibit participating in the study until study end.
Participation of any study personnel or their immediate dependents, family, or household members. Other exclusions for Cohort 1 and Cohort 3:
Pregnant or lactating female participant.
Female planning to become pregnant or planning to discontinue contraceptive precautions within 1 month after study intervention administration.

Contacts and Locations

Sponsors and CollaboratorsGlaxoSmithKline
Locations
GSK Investigational Site | Glendale Arizona, United States, 85308GSK Investigational Site | Phoenix Arizona, United States, 85284GSK Investigational Site | North Hollywood California, United States, 91606-3287GSK Investigational Site | Oakland California, United States, 94610GSK Investigational Site | Walnut Creek California, United States, 94598GSK Investigational Site | Hialeah Florida, United States, 33012GSK Investigational Site | North Miami Florida, United States, 33173GSK Investigational Site | Orlando Florida, United States, 32806GSK Investigational Site | Lexington Kentucky, United States, 40509GSK Investigational Site | Silver Spring Maryland, United States, 20904GSK Investigational Site | Rochester New York, United States, 14609GSK Investigational Site | Oklahoma City Oklahoma, United States, 73111GSK Investigational Site | Knoxville Tennessee, United States, 37909GSK Investigational Site | DeSoto Texas, United States, 75115GSK Investigational Site | Charlottesville Virginia, United States, 22911GSK Investigational Site | Wenatchee Washington, United States, 98801GSK Investigational Site | Coffs Harbour New South Wales, Australia, 2450GSK Investigational Site | Sydney New South Wales, Australia, 2010GSK Investigational Site | Sydney New South Wales, Australia, 2065GSK Investigational Site | Fortitude Valley Queensland, Australia, 4006GSK Investigational Site | Tarragindi Queensland, Australia, 4121GSK Investigational Site | Melbourne Victoria, Australia, 3051GSK Investigational Site | St Albans Victoria, Australia, 3021GSK Investigational Site | New Westminster British Columbia, Canada, V3L 3W4GSK Investigational Site | Victoria British Columbia, Canada, V8V 4A1GSK Investigational Site | Truro Nova Scotia, Canada, B2N 1L2GSK Investigational Site | Greater Sudbury Ontario, Canada, P3C 1X3GSK Investigational Site | Guelph Ontario, Canada, N1G 0B4GSK Investigational Site | London-Ontario Ontario, Canada, N5W 6A2GSK Investigational Site | Toronto Ontario, Canada, M4G 3E8GSK Investigational Site | Québec Quebec, Canada, G1N 4V3GSK Investigational Site | Québec Quebec, Canada, G1V 4G2GSK Investigational Site | Québec Quebec, Canada, G1V 4W2GSK Investigational Site | Saint-Charles-Borromée Quebec, Canada, J6E 2B4GSK Investigational Site | Sherbrooke Quebec, Canada, J1J 2G2GSK Investigational Site | Weinheim Baden-Wurttemberg, Germany, 69469GSK Investigational Site | Berlin , Germany, 10117GSK Investigational Site | Berlin , Germany, 10787GSK Investigational Site | Berlin , Germany, 13347GSK Investigational Site | Essen , Germany, 45355GSK Investigational Site | Mainz , Germany, 55116GSK Investigational Site | Wallerfing , Germany, 94574GSK Investigational Site | Witten , Germany, 58455GSK Investigational Site | Würzburg , Germany, 97070GSK Investigational Site | Ibaraki , Japan, 300-0062GSK Investigational Site | Kanagawa , Japan, 211-0041GSK Investigational Site | Tokyo , Japan, 155-0031GSK Investigational Site | Tokyo , Japan, 180-0022GSK Investigational Site | Cape Town , South Africa, 7530GSK Investigational Site | Cape Town , South Africa, 7700GSK Investigational Site | Johannesburg , South Africa, 2113GSK Investigational Site | Reiger Park , South Africa, 1459
Study Documents (Full Text)
Documents provided by GlaxoSmithKline: Study Protocol  May 2, 2024Documents provided by GlaxoSmithKline: Statistical Analysis Plan  January 14, 2025