Long-term Follow-up Study to Evaluate Safety and Immunogenicity of PXVX0317 Single or Booster Vaccination

NCT06007183 | Active Not Recruiting Phase 3 DMC FDA Drug

• 1 other identifier: EBSI-CV-317-008
• Study Type: interventional
• Target: 800
• Locations: 1 country
• Sites: 24

Brief Summary

The purpose of this phase 3 multicenter, randomized, double-blind, placebo-controlled rollover study is to evaluate the safety and long-term immunogenicity of CHIKV VLP vaccine in adult and adolescent participants and to evaluate CHIKV VLP booster vaccine induced serum neutralizing antibody (SNA) response at 3, 4, or 5 years post-initial CHIKV VLP vaccination.

Conditions

Chikungunya Virus Infection

Keywords

Chikungunya; PXVX0317; Vaccine; Immunogenicity; CHIKV VLP

Outcome Measures

Primary Outcomes (2)

• Proportion of participants maintaining a preboost anti-CHIKV SNA titer ≥100 at yearly intervals up to 5 years post-initial vaccination

  For all groups using the immunogenicity evaluable population (IEP) the proportion of participants maintaining a preboost anti-CHIKV SNA titer ≥100 (seroresponse rate, also considered the presumptive seroprotection rate) at yearly intervals up to 5 years post-initial vaccination in one of the feeder studies; only prebooster data will be summarized.

  5 years post-initial vaccination in feeder study EBSI-CV-317-004 or EBSI-CV317-005 until booster

• Proportion of vaccine boosted participants with composite booster response at 21 days after booster vaccination

  For IEP participants who receive a CHIKV VLP vaccine booster (Groups 1a, 2a, and 3a), proportion of participants with a boost response is defined as a composite of: * ≥4-fold rise in anti-CHIKV SNA titer from prebooster to postbooster measured at 21 days after booster for participants with a prebooster titer ≥100 OR * Anti-CHIKV SNA titer ≥100 and ≥4-fold increase in anti-CHIKV SNA titer from prebooster to postbooster measured at 21 days after booster vaccination for participants with a prebooster titer \<100. Note: Prebooster is the last SNA sample prior to booster dose, ideally the sample on boost day prior to booster dose administration but can be the time point prior if the boost day sample is missed or incorrectly processed.

  21 days after booster vaccination

Secondary Outcomes (4)

• Anti-CHIKV SNA Geometric Mean Titers (GMTs) at yearly intervals

  5 years post-initial vaccination in feeder study EBSI-CV-317-004 or EBSI-CV-317-005 until booster

• Anti-CHIKV SNA GMTs at 21 days postboost

  21 days postboost for Groups 1a, 2a, and 3a

• Anti-CHIKV SNA Geometric Mean Fold Increase (GMFI) Prebooster to Postbooster

  21 days after booster vaccination and 5 years post-initial vaccination in feeder study EBSI-CV-317-004 or EBSI-CV-317-005

• Booster Response at 21 Days Relative to 21-day Response in Feeder Study EBSI-CV-317-004 or EBSI-CV-317-005

  21 days after booster vaccination

Study Arms (7)

Group 1a

ACTIVE COMPARATOR

CHIKV VLP vaccine booster, 3 years post initial vaccination

Biological: CHIKV VLP vaccine booster

Group 1b

PLACEBO COMPARATOR

Placebo booster, 3 years post initial vaccination

Biological: Placebo booster

Group 2a

ACTIVE COMPARATOR

CHIKV VLP vaccine booster, 4 years post initial vaccination

Biological: CHIKV VLP vaccine booster

Group 2b

PLACEBO COMPARATOR

Placebo booster, 4 years post initial vaccination

Biological: Placebo booster

Group 3a

ACTIVE COMPARATOR

CHIKV VLP vaccine booster, 5 years post initial vaccination

Biological: CHIKV VLP vaccine booster

Group 3b

PLACEBO COMPARATOR

Placebo booster, 5 years post initial vaccination

Biological: Placebo booster

Group 4

NO INTERVENTION

Unrandomized or unboosted participants, for any reason

Interventions

CHIKV VLP vaccine booster BIOLOGICAL

CHIKV VLP vaccine is comprised of chikungunya virus virus-like particles (CHIKV VLP) 40mg, aluminum hydroxide 2% adjuvant, and formulation buffer supplied as a single dose of 0.8 mL in a pre-filled syringe, to be administered via intramuscular (IM) injection in the deltoid muscle.

Also known as: PXVX0317

Group 1a; Group 2a; Group 3a

Placebo booster BIOLOGICAL

Placebo is comprised of formulation buffer supplied as a single dose of 0.8 mL in a pre-filled syringe administered via IM injection in the deltoid muscle.

Group 1b; Group 2b; Group 3b

Eligibility Criteria

• Age: 12 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• Only within the EBSI-CV-317-004 feeder study informed consent form (ICF) (and/or assent form, as applicable), the participant voluntarily signed and agreed to be contacted or did not indicate they were not to be contacted for potential screening and enrollment in a future study (ie, EBSI-CV-317-008).
• Able and willing to provide informed consent (and assent, as applicable) voluntarily signed by participant (and guardian, as applicable) for participation in this rollover study EBSI-CV-317-008, including possible receipt of a booster dose of CHIKV VLP vaccine.
• Males or females, 12 years of age or older at the time of enrollment in the feeder study.
• Received a single dose of CHIKV VLP vaccine in one of the feeder studies, EBSI-CV-317-004 or EBSI-CV-317-005.
• Demonstrated compliance to the feeder study conduct (ie, rollover participant was without protocol deviations that excluded them from immunogenicity analysis in feeder study EBSI-CV-317-004 or EBSI-CV-317-005) without discontinuation or early withdrawal.
• Generally healthy, in the opinion of the investigator, based on medical history and physical examination.
• \- Women who are either: i. Not of childbearing potential (CBP): premenarche, surgically sterile (at least six weeks postbilateral tubal ligation or bilateral total salpingectomy, 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 sex-hormonal treatment). For women who are postmenopausal, documented follicle stimulating hormone (FSH) level of ≥40 mIU/mL must be obtained. If the FSH is \<40 mIU/mL, the participant must agree to use an acceptable form of contraception. or: ii. Meet all the below criteria:
• Negative serum pregnancy test at Prerandomization and Prebooster Visits
• Negative urine pregnancy test immediately prior to booster dose administration
• Use one of these acceptable methods of contraception (if women of CBP) for at least six months after booster:
• Hormonal contraceptives (eg, implants, pills, patches) initiated ≥30 days prior to booster dose administration
• Intrauterine device (IUD) inserted ≥30 days prior to booster dose administration
• Double barrier type of birth control (male condom with female diaphragm, male condom with cervical cap)
• Abstinence is acceptable only for adolescents (12-\<18 years of age) who are not sexually active.
• Women participants of CBP must use an acceptable method of contraception from ≥30 days prior to Randomization A or assignment to Group 1; those who are randomized to Groups 2 or 3 at year 3 can discontinue contraception until 30 days prior to booster dose administration, if desired. Women participants of CBP must use an acceptable method of contraception from ≥30 days prior to Randomization B through six-months postbooster vaccination dose (if applicable).

You may not qualify if:

• Received placebo treatment in the feeder study.
• Measurable anti-CHIKV SNA at Day 1 in the feeder study.
• History of severe allergic reaction or anaphylaxis to any component of the investigational product (IP).
• Receipt of either an investigational or licensed CHIKV vaccine (excluding prior receipt of CHIKV VLP vaccine).
• Evidence of substance abuse that, in the opinion of the investigator, could adversely impact the individual's participation or the conduct of the study.
• Any other medical condition or general reason that, in the opinion of the investigator, could adversely impact the individual's participation or the conduct of the study.
• Bavarian Nordic staff members and their families, contractors, agents, business partners, and anyone with a financial interest in the outcome of the study.
• Participation or planned participation in an investigational clinical trial, excluding feeder studies EBSI-CV-317-004 or EBSI-CV-317-005 (eg, vaccine, drug, medical device, or medical procedure) for the following time periods:
• Group 1: 30 days prior to Randomization A or assignment to Group 1 at Visit 6 through Visit 7 Group 2: 30 days prior to Randomization A at Visit 6 until the Randomization A visit and 30 days prior to booster dose at Visit 8 through Visit 9 Group 3: 30 days prior to Randomization A at Visit 6 until the Randomization A visit and 30 days prior to booster dose at Visit 10 through EOS Visit Group 4: 30 days prior to Randomization A at Visit 6 until the Randomization A visit Note: Participation in an observational trial or follow-up phase of a trial may be allowed; however, these instances should be discussed with this study's medical monitor (MM).
• Currently breastfeeding.
• Positive laboratory evidence of current infection with human immunodeficiency virus (HIV), hepatitis C virus (HCV) or hepatitis B virus (HBV).
• Receipt or anticipated receipt of blood or blood-derived products from 90 days prior to Prebooster Visit through 21 days postbooster dose.
• Acute disease within the last 14 days prior to booster dose (participants with an acute mild febrile illness can be considered for a deferral of vaccination two weeks after the illness has resolved and treatment has been completed).
• Receipt or anticipated receipt of any vaccine from 30 days prior to booster dose through 21 days postbooster.
• Note: Participants that are ineligible or decline booster will be included in Group 4 (unrandomized or unboosted) for follow-up unless consent/assent for follow-up is withdrawn.

Sponsors & Collaborators

• Bavarian Nordic: lead

Study Sites (24)

Alliance for Multispecialty Research, LLC

Mobile, Alabama, 36608, United States

Location

Alliance for Multispecialty Research, LLC

Tempe, Arizona, 85281, United States

Location

Optimal Research, LLC

Melbourne, Florida, 32934, United States

Location

Suncoast Research Associates, LLC

Miami, Florida, 33173, United States

Location

Synexus Clinical Research US, Inc.

Chicago, Illinois, 60602, United States

Location

Optimal Research, LLC

Peoria, Illinois, 61614, United States

Location

Alliance for Multispecialty Research, LLC

Newton, Kansas, 67114, United States

Location

Alliance for Multispecialty Research, LLC

Wichita, Kansas, 67207, United States

Location

Alliance for Multispecialty Research, LLC

Lexington, Kentucky, 40509, United States

Location

Alliance for Multispecialty Research, LLC

Kansas City, Missouri, 64114, United States

Location

Wr-Crcn, Llc

Las Vegas, Nevada, 89106, United States

Location

Alliance for Multispecialty Research, LLC

Las Vegas, Nevada, 89119, United States

Location

Rochester Clinical Research, LLC

Rochester, New York, 14609, United States

Location

M3 Wake Research Inc.

Raleigh, North Carolina, 27612, United States

Location

Velocity Clinical Research, Cleveland

Cleveland, Ohio, 44122, United States

Location

Lynn Institute of Norman

Norman, Oklahoma, 73072, United States

Location

Velocity Clinical Research, Medford

Medford, Oregon, 97504, United States

Location

Velocity Clinical Research, Providence

East Greenwich, Rhode Island, 02818, United States

Location

Velocity Clinical Research, Austin

Cedar Park, Texas, 78613, United States

Location

DM Clinical Research

Houston, Texas, 77081, United States

Location

BFHC Research, LLC

San Antonio, Texas, 78249, United States

Location

DM Clinical Research

Tomball, Texas, 77375, United States

Location

Velocity Clinical Research, Salt Lake City

West Jordan, Utah, 84088, United States

Location

Alliance for Multispecialty Research, LLC

Norfolk, Virginia, 23502, United States

Location

MeSH Terms

Conditions

Chikungunya Fever

Condition Hierarchy (Ancestors)

Alphavirus Infections; Arbovirus Infections; Vector Borne Diseases; Infections; Mosquito-Borne Diseases; Virus Diseases; Togaviridae Infections; RNA Virus Infections

Study Officials

• Patrick Ajiboye, MD

  Bavarian Nordic

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR
• Masking Details: Participants, care providers, and investigator will not be blinded for the timing of when the participant will receive the vaccine booster or placebo booster. They will be blinded to all booster treatment assignments (vaccine booster or placebo booster).
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Model Details: All eligible participants in the youngest (12 to \<18 years) and oldest 2 (≥65 years) age groups will be assigned to a booster at Year 3 (Group 1). All other participants will be randomized 1:1:1 to a booster at Year 3 (Group 1), 4 (Group 2), or 5 (Group 3). Prior to booster dose administration participants will be randomized 1:1 to CHIKV VLP vaccine booster or placebo booster.

Study Record Dates

• First Submitted: August 18, 2023
• First Posted: August 23, 2023
• Study Start: August 30, 2023
• Primary Completion (Estimated): April 1, 2028
• Study Completion (Estimated): August 1, 2028
• Last Updated: April 3, 2025

Record last verified: 2025-04

Data Sharing

• IPD Sharing: Will not share

Locations

US (24)