A Phase 3 Safety and Immunogenicity Trial of the VLP-Based Chikungunya Virus Vaccine PXVX0317 in Adults ≥65 Years of Age
Overview
- Phase
- Phase 3
- Intervention
- CHIKV VLP/adjuvant
- Conditions
- Chikungunya Virus
- Sponsor
- Bavarian Nordic
- Enrollment
- 413
- Locations
- 10
- Primary Endpoint
- Anti-CHIKV SNA Titer (NT80) Seroresponse Rates at Day 22 in Baseline Seronegative Participants
- Status
- Completed
- Last Updated
- last year
Overview
Brief Summary
The purpose of this phase 3, randomized, double-blind, placebo-controlled study is to evaluate the safety and immunogenicity to PXVX0317 in adults ≥65 years of age.
Detailed Description
Co-primary Objectives: * To compare the anti-CHIKV serum neutralizing antibody (SNA) response to PXVX0317 and placebo at Day 22, as measured by geometric mean titer (GMT) and clinically relevant difference in seroresponse rate (PXVX0317 minus placebo) in adults ≥65 years of age. * To evaluate the safety of PXVX0317 in adults ≥65 years of age Secondary Objectives: * To compare the anti-CHIKV SNA response to PXVX0317 and placebo at Day 15 and Day 183, as measured by GMT and seroresponse rate. * To compare the anti-CHIKV SNA response to PXVX0317 and placebo in participants ≥65 to \<75 and ≥75 years of age as measured by GMT and seroresponse rate.
Investigators
Eligibility Criteria
Inclusion Criteria
- •Able and willing to provide informed consent voluntarily signed by participant. Must verbalize understanding of the general procedures of, and reason for the study.
- •Males or females, ≥65 years of age.
- •Able to complete all scheduled visits and comply with all study procedures.
- •Women who are not of childbearing potential (CBP): surgically sterile (at least six weeks post bilateral tubal ligation, bilateral oophorectomy or hysterectomy); or postmenopausal (defined as a history of ≥12 consecutive months without menses prior to randomization in the absence of other pathologic or physiologic causes, following cessation of exogenous post menopausal sex-hormonal treatment).
- •Participants must be in stable health in the opinion of the investigator for at least 30 days prior to screening (eg, no hospital admission for acute illness in the last 30 days prior to screening).
Exclusion Criteria
- •Participation or planned participation in an investigational clinical trial (eg, vaccine, drug, medical device, or medical procedure) within 30 days of Day 1 and for the duration of the study. Note: Participation in an observational trial or follow-up phase of a trial may be allowed; however, these instances should be discussed with the sponsor's medical monitor (MM) prior to enrollment.
- •Prior receipt of any CHIKV vaccine.
- •Positive laboratory evidence of current infection with human immunodeficiency virus (HIV), hepatitis C virus (HCV) or hepatitis B virus (HBV).
- •Body mass index (BMI) ≥35 kg/m\^2
- •History of any known or suspected allergy or history of anaphylaxis to any component of the investigational product (IP).
- •History of any known congenital or acquired immunodeficiency or immunosuppressive condition that could impact response to vaccination (eg, leukemia, lymphoma, malignancy, functional or anatomic asplenia, alcoholic cirrhosis). Note: History of basal cell and squamous cell carcinoma of the skin or carcinoma in situ of the cervix considered cured would not be exclusionary. History of a malignancy considered cured from over five years from the date of screening with minimal risk of recurrence is not exclusionary.
- •Prior or anticipated use of systemic immunomodulatory or immunosuppressive medications from six months prior to screening through Day
- •Note: Systemic corticosteroid use at a dose or equivalent dose of 20 mg of prednisone daily for 14 days or more within 90 days of screening through Day 22 is exclusionary. The use of inhaled, intranasal, topical, or ocular steroids is allowed.
- •Bleeding disorder or receipt of anticoagulants in the 21 days prior to screening, contraindicating intramuscular (IM) vaccination, as judged by the investigator.
- •Moderate or severe acute illness with or without fever (oral temperature ≥100.4°F or 38.0°C).
Arms & Interventions
Group 1 - PXVX0317
PXVX0317 vaccine is comprised of chikungunya virus virus-like particles (CHIKV VLP), adsorbed on aluminum hydroxide adjuvant.
Intervention: CHIKV VLP/adjuvant
Group 2 - Placebo
Placebo is comprised of formulation buffer.
Intervention: Placebo
Outcomes
Primary Outcomes
Anti-CHIKV SNA Titer (NT80) Seroresponse Rates at Day 22 in Baseline Seronegative Participants
Time Frame: 21 days postvaccination
Difference in anti-CHIKV SNA titer (NT80) seroresponse rate (PXVX0317 minus placebo) and associated 95 percent confidence interval (CI) at Day 22.
Anti-CHIKV SNA Titer (NT80) Geometric Mean Titers (GMT) at Day 22
Time Frame: 21 days postvaccination
Anti-CHIKV SNA titer (NT80) GMT and associated 95 percent CIs at Day 22 for PXVX0317 and placebo.
Incidence of Solicited Adverse Events (AE)
Time Frame: 7 days postvaccination
Incidence of solicited AEs through Day 8 for PXVX0317 (CHIKV VLP vaccine) and placebo for all age strata combined (safety population).
Incidence of Unsolicited AEs
Time Frame: 28 days postvaccination
Incidence of unsolicited AEs through Day 29 for PXVX0317 (CHIKV VLP vaccine) and placebo for all age strata combined (safety population).
Incidence of Serious Adverse Events (SAE)
Time Frame: 182 days postvaccination
Incidence of SAEs through Day 183 for PXVX0317 (CHIKV VLP vaccine) and placebo for all age strata combined (safety population).
Incidence of Medically Attended Adverse Events (MAAE)
Time Frame: 182 days postvaccination
Incidence of MAAEs through Day 183 for PXVX0317 (CHIKV VLP vaccine) and placebo for all age strata combined (safety population).
Incidence of Adverse Events of Special Interest (AESI)
Time Frame: 182 days postvaccination
Incidence of AESIs, through Day 183 for PXVX0317 (CHIKV VLP vaccine) and placebo for all age strata combined (safety population).
Secondary Outcomes
- Anti-CHIKV SNA Titer (NT80) Seroresponse Rates at Days 15 and 183(Day 15 and 183 (14 and 182 days postvaccination, respectively))
- Anti-CHIKV SNA GMTs at Days 15 and 183(Day 15, and 183 (14 and 182 days postvaccination, respectively))
- Anti-CHIKV SNA Geometric Mean Fold Increase (GMFI)(Day 15, 22, and 183 (14, 21 and 182 days postvaccination, respectively))
- Subjects With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline(Day 15, 22 and 183 (14, 21 and 182 days postvaccination, respectively))