A Study of RSV-HMPV Bivalent Vaccine VXB-241 in Older Adults
NCT Number: NCT06556147
Status: NOT_YET_RECRUITING
Study Type: INTERVENTIONAL
Phases: PHASE1
Conditions: Healthy Volunteers
Interventions: BIOLOGICAL: VXB-241 60 mcg (Low Dose)|BIOLOGICAL: VXB-241 120 mcg (Medium Dose)|BIOLOGICAL: VXB-241 240 mcg (Medium-high Dose)|BIOLOGICAL: VXB-241 480 mcg (High Dose)|BIOLOGICAL: VXB-241|OTHER: Placebo|BIOLOGICAL: Arexvy 120 mcg
Sponsor: Vicebio Australia Proprietary Limited
Sex: ALL
Age: ADULT, OLDER_ADULT
Enrollment: 136
Study Design: Allocation: RANDOMIZED|Intervention Model: SEQUENTIAL|Masking: DOUBLE (PARTICIPANT, OUTCOMES_ASSESSOR)|Primary Purpose: PREVENTION
Start Date: 2024-08-14
Completion Date: 2027-05
Locations: University of the Sunshine Coast, Morayfield, Queensland, 4506, Australia|University of the Sunshine Coast, Sippy Downs, Queensland, 4556, Australia|University of the Sunshine Coast, South Brisbane, Queensland, 4101, Australia

Summary:
The main purposes of this study are to assess the safety, reactogenicity and immunogenicity of 4 dose levels of the bivalent combination Respiratory Syncytial Virus (RSV) / human Metapneumovirus (hMPV) vaccine candidate VXB-241 when administered as a single-dose regimen to healthy adults 60 to 83 years of age, and to assess the impact of revaccination approximately 1 year later.

Primary Outcome Measures: Proportion of Older Adult Participants With 1 or More Unsolicited AEs, 1 month after first IMP injection (Days 1 to 30)|Proportion of Older Adult Participants With 1 or More Solicited AEs, 7 days after first IMP injection (Days 1 to 8)|Geometric Mean Fold Increase (GMFI) of RSV-A, RSV-B, hMPV-A, and hMPV-B Serum Neutralizing Antibody Titers in Older Adults, GMFI is defined as geometric mean of ratios of specific antibody titer/concentration at each post-vaccination time point over pre-vaccination baseline., Pre-injection baseline to 1 month (Day 30) after first IMP injection|Ratio of Dose-response Curves for GMFIs of RSV-A, RSV-B, hMPV-A and hMPV-B Serum Neutralizing Antibody Titers in Older Adults, Ratio of VXB-241 dose versus GMFI of RSV-A, RSV-B, hMPV-A and hMPV-B will be calculated., Pre-injection baseline to 1 month (Day 30) after first IMP injection
Secondary Outcome Measures: Proportion of Older Adult Participants With 1 or More Unsolicited AEs and With 1 or More Severe Unsolicited AE, 1 month after first IMP injection (Days 1 to 30) and 1 month after second IMP injection (revaccination, Days 364 to 394)|Proportion of Older Adult Participants With Serious Adverse Events (SAEs), AEs of Special Interest (AESIs), and Premature Discontinuation Associated AEs (PDAEs), 1 month after first IMP injection (Days 1 to 30) and 1 month after second IMP injection (revaccination, Days 364 to394), and throughout follow-up (Days 1 to 720)|Mean Change From Baseline for Abnormal and Severe Abnormal Hematology Laboratory Values for Hemoglobin in Older Adults, 7 days (Day 8) and 1 month (Day 30) after first IMP injection, and 1 month (Day 394) after second IMP injection (revaccination|Mean Change From Baseline for Abnormal and Severe Abnormal Hematology Laboratory Values for Red Blood Cells, White Blood Cells, and Platelet Count in Older Adults, 7 days (Day 8) and 1 month (Day 30) after first IMP injection, and 1 month (Day 394) after second IMP injection (revaccination|Mean Change From Baseline for Abnormal and Severe Abnormal Blood Chemistry Laboratory Values for Alanine Transaminase (ALT), Aspartate Transaminase (AST), and Alkaline Phosphatase in Older Adults, 7 days (Day 8) and 1 month (Day 30) after first IMP injection, and 1 month (Day 394) after second IMP injection (revaccination|Mean Change From Baseline for Abnormal and Severe Abnormal Blood Chemistry Laboratory Values for Total Bilirubin, Creatinine, and Urea in Older Adults, 7 days (Day 8) and 1 month (Day 30) after first IMP injection, and 1 month (Day 394) after second IMP injection (revaccination|Proportion of Older Adult With Abnormal and Severe Abnormal Values for Hematology Laboratory Parameter, 7 days (Day 8) and 1 month (Day 30) after first IMP injection, and 1 month (Day 394) after second IMP injection (revaccination)|Proportion of Older Adult With Abnormal Values and Severe Abnormal Values for Blood Chemistry Laboratory Parameter, 7 days (Day 8) and 1 month (Day 30) after first IMP injection, and 1 month (Day 394) after second IMP injection (revaccination)|Proportion of Older Adult Participants With Solicited AEs, 7 days after 2nd IMP injection (revaccination, Day 364 to 371)|GMFI of RSV-A, RSV-B, hMPV-A, and hMPV-B Serum Neutralizing Antibody Titers in Older Adults, Pre-injection baseline to 6 months (Day 182) and 12 months (Day 364) after first IMP injection, and 1 month (Day 394), 6 months (Day 546), and 12 months (Day 720) after second IMP injection (revaccination)|Geometric Mean Titers (GMTs) of RSV-A, RSV-B, hMPV-A, and hMPV-B Serum Neutralizing Antibody Titers in Older Adults, Pre-injection baseline to 1 month (Day 30), 6 months (Day 182) and 12 months (Day 364) after first IMP injection, and 1 month (Day 394), 6 months (Day 546), and 12 months (Day 720) after second IMP injection (revaccination)|Proportion of Older Adult Participants with Sero-response Greater Than or Equal to (>=) 4-fold (SSR-4) and 8-fold (SSR-8) Increase from Baseline in Neutralizing Antibody Titers for RSV-A, RSV-B, hMPV-A and hMPV-B, Pre-injection baseline to 1 month (Day 30), 6 months (Day 182) and 12 months (Day 364) after first IMP injection, and 1 month (Day 394), 6 months (Day 546), and 12 months (Day 720) after second IMP injection (revaccination)|GMFI of RSV Pre-fusion Protein (Pre-F) and hMPV Pre-F Serum Immunoglobulins G (IgG) Concentrations in Older Adults, Pre-injection baseline to 1 month (Day 30), 6 months (Day 182) and 12 months (Day 364) after first IMP injection, and 1 month (Day 394), 6 months (Day 546), and 12 months (Day 720) after second IMP injection (revaccination)|Geometric Mean Concentrations (GMC) of Serum IgG Versus RSV Pre-F and hMPV Pre-F in Older Adults, 1 month (Day 30), 6 months (Day 182), and 12 months (Day 364) after first IMP injection and 1 month (Day 394), 6 months (Day 546) and 12 months (Day 720) after second IMP injection (revaccination)|Geometric Mean Ratios (GMRs) of Fold Increase of RSV-A and RSV-B Neutralizing Serum Antibody Titers Versus Fold Increase of RSV Pre-F Serum IgG Concentration in Older Adults, Pre-injection baseline to 1 month (Day 30), 6 months (Day 182) and 12 months (Day 364) after first IMP injection, and 1 month (Day 394), 6 months (Day 546), and 12 months (Day 720) after second IMP injection (revaccination)|GMR of Fold Increase of hMPV-A and hMPV-B Neutralizing Serum Antibody Titers Versus Fold Increase of hMPV Pre-F Serum IgG Concentration in Older Adults, Pre-injection baseline to 1 month (Day 30), 6 months (Day 182) and 12 months (Day 364) after first IMP injection, and 1 month (Day 394), 6 months (Day 546), and 12 months (Day 720) after second IMP injection (revaccination)