A Phase 2 Open-label Study to Assess the Safety and Immunogenicity of an Alum-adjuvanted Chikungunya Virus-like Particle Vaccine (PXVX0317) in Prior Recipients of Other Alphavirus Vaccines Versus Alphavirus Naïve Controls.
Overview
- Phase
- Phase 2
- Intervention
- Chikungunya
- Conditions
- Chikungunya
- Sponsor
- Bavarian Nordic
- Enrollment
- 60
- Locations
- 2
- Primary Endpoint
- Percentage of Participants With 4-fold Rise in Anti-CHIKV Neutralizing Antibody Response
- Status
- Completed
- Last Updated
- last year
Overview
Brief Summary
This was a phase 2 parallel-group age- and gender-matched open label study in healthy adults 18-65 years of age to assess the safety and immunogenicity of an alum-adjuvanted chikungunya virus-like particle vaccine (PXVX0317; CHIKV VLP vaccine) in prior recipients of other alphavirus vaccines versus alphavirus naïve controls.
Detailed Description
It is currently unknown whether prior exposure to heterologous alphaviruses will enhance or interfere with immune responses to chikungunya virus (CHIKV) exposure or vaccination. The objective of this study was to evaluate the safety and immunogenicity of the chikungunya vaccine candidate PXVX0317 when administered to prior recipients of experimental alphavirus vaccines versus alphavirus naïve gender- and age-matched controls.
Investigators
Eligibility Criteria
Inclusion Criteria
- •Age 18 to 65 years old (inclusive)
- •For women of childbearing potential, a negative pregnancy test at screening and on vaccination day, practicing highly effective contraception for at least 30 days prior to vaccination, and willing to use a highly effective method of contraception through study completion.
- •Able and willing to provide informed consent for study participation prior to screening procedures.
- •Free of obvious health problems as established by medical history and clinical examination at screening and enrollment.
- •Available to participate for the duration of the study (approximately 8 months).
- •For the cohort of prior alphavirus vaccine recipients, a documented history of prior alphavirus vaccination.
Exclusion Criteria
- •Acute disease or febrile illness at the time of screening or enrollment.
- •Clinically significant cardiac, respiratory, rheumatologic or other medical or psychiatric condition that, in the opinion of the Investigator, places the subject at increased risk or affects their ability to understand and comply with study procedures.
- •Abnormal screening lab test result that, in the opinion of the investigator, obscures interpretation of the safety data or suggests a clinically significant cardiac, respiratory, rheumatologic or other medical condition that places the subject at increased risk.
- •Pregnant, lactating or planning to become pregnant during the study period.
- •Laboratory evidence of infection with Hepatitis B, C or HIV.
- •History of naturally (non-laboratory) acquired chikungunya or other alphavirus infection or travel to a WHO-designated chikungunya-endemic region within 30 days prior to Day
- •History of acute allergic reaction to any component of CHIKV VLP vaccine or Alhydrogel®.
- •Current (30 days prior to Day 1) or anticipated use of systemic immunomodulatory or immunosuppressive medications.
- •History of splenectomy, immunosuppressive condition, autoimmune disease, or immunodeficient condition.
- •Family history of congenital or hereditary immunodeficiency.
Arms & Interventions
Prior Alpha
All study participants received the same Investigational Product according to the same schedule. Participants were prior recipients of experimental alphavirus vaccines.
Intervention: Chikungunya
Control: Naïve Alpha
All study participants received the same Investigational Product according to the same schedule. The alphavirus vaccine naïve participants will serve as controls for determining the effect of pre-existing alphavirus immunity on vaccine safety and immunogenicity.
Intervention: Chikungunya
Outcomes
Primary Outcomes
Percentage of Participants With 4-fold Rise in Anti-CHIKV Neutralizing Antibody Response
Time Frame: Day 22 (21 days after vaccination)
Seroconversion, defined as a 4-fold or greater rise in neutralizing antibody against chikungunya virus, as determined by luciferase-based assay (NT80), induced by PXVX0317. PXVX0317 was administered to prior alphavirus vaccine recipients versus gender- and age-matched controls.
Secondary Outcomes
- Geometric Mean Titer of Anti-CHIKV Neutralizing Antibody Response(Day 1, 8, 22, 29, 57, 182)
- Percentage of Participants With 4-fold Rise in Anti-CHIKV Neutralizing Antibody Response(Day 8, 29, 57, 182)
- Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds(Day 1, 8, 22, 29, 57, 182)
- Geometric Mean Titer of Anti-CHIKV Total Antibody Response(Day 1, 22, 29)
- Percentage of Participants With 4-fold Rise in Anti-CHIKV Total Antibody Response(Day 22, 29)
- Geometric Mean Titer of Anti-VEEV Neutralizing Antibody Response(Day 1, 22, 29)
- Number of Participants With Anti-CHIKV Total Antibody Titers of at Least 40,160 or 640(Days 1, 22, and 29)
- Percentage of Participants With 4-fold Rise in Anti-VEEV Neutralizing Antibody Response(Day 22 and 29)
- Percentage of Participants With Anti-VEEV PRNT Neutralizing Activity at or Above Selected Thresholds(Day 1, 22, 29)
- Geometric Mean Titer of Anti-VEEV Total Antibody Response(Day 1, 22, 29)
- Percentage of Participants With 4-fold Rise in Total ELISA IgG Antibody Against VEEV(Day 22, 29)
- Number of Participants With Anti-VEEV Total Antibody Titers of at Least 40,160 or 640(Days 1, 22, and 29)