Extension Study to Evaluate the Safety and Immunogenicity of a Revaccination Dose of the RSVPreF3 OA Investigational Vaccine in Adults 60 Years and Older Who Participated in the RSV OA=ADJ-002 Study

Study Overview
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Brief Summary
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Nine different formulations of the RSVPreF3 OA investigational vaccine were tested in the parent study (NCT03814590). Based on safety and immunogenicity data from the parent study, RSVPreF3 OA investigational vaccine will be evaluated in further clinical research. Participants in selected groups will be invited to participate in this extension study. All participants who will be enrolled in the current extension study will receive the RSV investigational vaccine approximately 18 months after they received their respective dose-2 in the parent study.

Official Title
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A Phase 2b, Open-label, Multi-center, Extension Study to Evaluate the Safety and Immunogenicity of a Revaccination Dose of the RSVPreF3 Older Adults (OA) Investigational Vaccine Administered Intramuscularly 18 Months Post-Dose 2 in Adults 60 Years and Older Who Participated in the RSV OA=ADJ-002 Study

Conditions
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Respiratory Syncytial Virus Infections

Intervention / Treatment
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* Biological: RSVPreF3 OA investigational vaccine (GSK3844766A)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male or female participants, who received 2 doses of RSVPreF3 OA investigational vaccine and formulations with matched adjuvant in part B of the parent study RSV OA=ADJ-002: recombinant RSVPreF3 antigen doses of low, medium and high strengths with adjuvant. Participants who, in the opinion of the investigator, can and will comply with the requirements of the protocol (e.g. completion of the diary cards, return for the follow-up visit, be available for contact) Written informed consent obtained from the participant prior to performance of any study specific procedure. Exclusion Criteria: Medical conditions Significant underlying illness or administered therapy that in the opinion of the investigator would be expected to prevent participation in the study. Any confirmed or suspected immunosuppressive or immunodeficient condition based on information on concomitant medication/vaccination collected prior to the study start and physical examination. Serious or unstable chronic illness that developed during or after the parent study. Patients 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 by the investigator as clinically stable. Recurrent or un-controlled neurological disorders or seizures that developed during or after the parent study. 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. Significant underlying illness that developed during or after the parent study, that in the opinion of the investigator would be expected to prevent completion of the study. Lymphoproliferative disorder and malignancy developed during or after the parent study. Any medical condition that developed during or after the parent study, that in the judgment of the investigator would make intramuscular injection unsafe. Previous vaccination with RSV vaccine, other than the one in the parent study. Prior/Concomitant therapy Use of any investigational or non-registered product (drug, vaccine or medical device) other than the study vaccine during the period beginning 30 days before the dose of study vaccine, or planned use during the study period. 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 vaccine administration, with the exception of inactivated, split virion and subunit influenza vaccines which can be administered up to 14 days before or from 30 days after the study vaccination. Administration of long-acting immune-modifying drugs or planned administration at any time during the study period. Administration of immunoglobulins and/or any blood products or plasma derivatives during the period starting 90 days before the dose of study vaccine or planned administration during the study period. Chronic administration (defined as more than 14 consecutive days in total) of immunosuppressants or other immune-modifying drugs during the period starting 90 days prior to the vaccine dose or planned administration during the study period. For corticosteroids, this will mean prednisone ≥20 mg/day, or equivalent. Inhaled and topical steroids are allowed. Confirmed use or anticipated use of immunosuppressive/cytotoxic therapy. 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. Other exclusions Bedridden participants. Planned move to a location that will prohibit participating in the trial. History of chronic alcohol consumption and/or drug abuse that developed during or after the parent study as deemed by the investigator to render the potential participant unable/unlikely to provide accurate safety reports or comply with study procedures.

Ages Eligible for Study
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Minimum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Group High Dose_Adjuvanted<br>Participants in one of the high dose adjuvanted groups in part B of the parent study RSV OA=ADJ-002: Group High Dose Adjuvanted will receive one revaccination dose of the RSVPreF3 OA investigational vaccine in the current study by intramuscular (IM) injection in the non-dominant arm. | Biological: RSVPreF3 OA investigational vaccine (GSK3844766A)<br>* RSVPreF3 OA investigational vaccine administered intramuscularly in the deltoid region of the non-dominant arm, at Day 1 (18 months post-Dose 2 in the RSV OA=ADJ-002 parent study).<br>|
| Experimental: Group Medium Dose_Adjuvanted<br>Participants in one of the medium dose adjuvanted groups in part B of the parent study RSV OA=ADJ-002: Group Medium Dose Adjuvanted will receive one revaccination dose of the RSVPreF3 OA investigational vaccine in the current study by IM injection in the non-dominant arm. | Biological: RSVPreF3 OA investigational vaccine (GSK3844766A)<br>* RSVPreF3 OA investigational vaccine administered intramuscularly in the deltoid region of the non-dominant arm, at Day 1 (18 months post-Dose 2 in the RSV OA=ADJ-002 parent study).<br>|
| Experimental: Group Low Dose_Adjuvanted<br>Participants in one of the low dose adjuvanted groups in part B of the parent study RSV OA=ADJ-002: Group Low Dose Adjuvanted will receive one revaccination dose of the RSVPreF3 OA investigational vaccine in the current study by IM injection in the non-dominant arm. | Biological: RSVPreF3 OA investigational vaccine (GSK3844766A)<br>* RSVPreF3 OA investigational vaccine administered intramuscularly in the deltoid region of the non-dominant arm, at Day 1 (18 months post-Dose 2 in the RSV OA=ADJ-002 parent study).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Participants With Any Solicited Administration Site Adverse Events (AEs) | Assessed solicited administration site AEs are erythema, pain and swelling. Any pain is defined as any pain regardless of intensity grade. Any injection site erythema/swelling is scored with a diameter larger than (>) 20 millimeters (mm). | During the 4-day follow-up period post-vaccination (i.e. on the day of vaccination [Day 1] and 3 subsequent days) | 
| Number of Participants With Any Solicited Systemic AEs | Assessed solicited systemic AE is fever (any temperature greater than or equal to 38.0 °C - the preferred location for measuring temperature being the oral cavity). Any is defined as occurrence of the symptom regardless of intensity grade or relation to study. | During the 4-day follow-up period post-vaccination (i.e. on the day of vaccination [Day 1] and 3 subsequent days) | 
| Number of Participants With Any Unsolicited AEs | An unsolicited AE is any AE reported in addition to those solicited during the clinical study. Also, any 'solicited' symptom with onset outside the specified period of follow-up for solicited symptoms is reported as an unsolicited AE. Any is defined as the occurrence of any unsolicited AE regardless of intensity grade or relation to study vaccination. | During the 30-day follow-up period post-vaccination (i.e., on the day of vaccination [Day 1] and 29 subsequent days) | 
| Number of Participants With Any Serious Adverse Events (SAEs) up to 30 Days Post-vaccination | An SAE is any untoward medical occurrence that results in death, is life-threatening, requires hospitalization or prolongation of existing hospitalization or results in disability/incapacity. Any is defined as any occurrence of SAE regardless of intensity grade or relation to study vaccination. | From Day 1 up to 30 days post-vaccination (Day 31) | 
| Number of Participants With Any Potential Immune-mediated Diseases (pIMDs) up to 30 Days Post-vaccination | pIMDs are a subset of AEs that include autoimmune diseases and other inflammatory and/or neurologic disorders of interest which may or may not have an autoimmune etiology. Any is defined as the occurrence of any pIMD regardless of intensity grade or relation to study vaccination. | From Day 1 up to 30 days post-vaccination (Day 31) | 
| Humoral Immune Response in Terms of Neutralizing Antibody Titers Against Respiratory Syncytial Virus (RSV)-Serotype A | Serological assays for the determination of functional antibodies against RSV-A are performed by neutralization assay. Anti RSV-A neutralizing antibody titers are given as Geometric Mean Titers (GMTs) and expressed as Estimated Dose: serum dilution giving a 60% reduction of the signal compared to a control without serum (ED60). | At 30 days post-vaccination (Day 31) | 
| Humoral Immune Response in Terms of Neutralizing Antibody Titers Against RSV-serotype B | Serological assays for the determination of functional antibodies against RSV-B are performed by neutralization assay. Anti RSV-B neutralizing antibody titers are given as GMTs and expressed as ED60. | At 30 days post-vaccination (Day 31) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Humoral Immune Response in Terms of RSVPreF3-specific Immunoglobulin G (IgG) Antibody Concentrations | The detection and the quantification of total IgG antibodies directed against RSVPreF3 in human serum samples were based on an indirect Enzyme-Linked Immunosorbent Assay (ELISA). Anti RSVPreF3 antibody concentration is given in geometric mean concentration (GMC) and is expressed in ELISA Laboratory Units per milliliter (ELU/mL). | At 30 days post-vaccination (Day 31) | 
| Frequency of RSVPreF3-specific Cluster of Differentiation 4+ (CD4+) T-cells Identified as Expressing at Least Two Markers | Among markers expressed are interleukin-2 (IL2), cluster of 40 ligand (CD40L), tumour necrosis factor alpha (TNF α) and interferon gamma (IFN γ), in vitro upon stimulation with RSVPreF3 peptide preparations. | At 30 days post-vaccination (Day 31) | 
| Number of Participants With Any SAEs, up the End of Follow-up Study Period (Month 6) | An SAE is any untoward medical occurrence that results in death, is life-threatening, requires hospitalization or prolongation of existing hospitalization or results in disability/incapacity. | From Day 1 up to the end of follow-up period (Month 6) | 
| Number of Participants Reporting pIMDs up to the End of Follow-up Study Period (Month 6) | pIMDs are a subset of AEs that include autoimmune diseases and other inflammatory and/or neurologic disorders of interest which may or may not have an autoimmune etiology. | From Day 1 up to the end of follow-up period (Month 6) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Respiratory syncytial virus, Vaccine, Safety, Immunogenicity