Open-label, Randomized Study in a Pediatric Population in a JEV (Japanese Encephalitis Virus)-Endemic Country

Phase 3

Completed

Conditions: Japanese Encephalitis

Interventions: Biological: IXIARO

Registration Number: NCT01296360

Lead Sponsor: Valneva Austria GmbH

Brief Summary: This is a randomized, open-label Phase 3 study including children aged \>9 months to \<17 years and 7 months who have been vaccinated with IXIARO in study IC51-323.

Detailed Description: This is a randomized, open-label Phase 3 study including children aged \>9 months to \<17 years and 7 months who have been vaccinated with IXIARO in the previous study IC51-323.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 300

Inclusion Criteria

Children and adolescents who have completed study IC51-323 and received both IXIARO vaccinations according to protocol.
Children who have received the dose confirmed for their age group.
Male or female healthy children and adolescents aged ≥9 months to <17 years and 7 months at the time of enrolment into this study.
Written informed consent by the subject's legal representative(s), according to local requirements, and written informed assent of the subject, if applicable.
Female subjects: either no childbearing potential or negative pregnancy test (pregnancy test to be performed in female subjects after onset of menarche) at Visits 1, 2 and 2a as stipulated by the protocol. For females after menarche willingness to practice a reliable method of contraception

Exclusion Criteria

Vaccination against JE virus (JEV) (except within study IC51-323 and IC51 325), Yellow fever, West Nile virus and Dengue fever at any time prior to or planned during the study.
History of or clinical manifestation of any Flavivirus disease during IC51-323 or IC51 325.
Participation in another study with an investigational drug during IC51 323 or IC51 325.
Planned active or passive immunization within 2 weeks before and 1 week after the IXIARO booster.
History of or development of any immunodeficiency including post-organ-transplantation after inclusion into IC51-323 or IC51 325.
History of or development of an autoimmune disease during study IC51-323 or IC51 325.
- Administration of chronic (defined as more than 14 days) immunosuppressants or other immune-modifying medications started during IC51-323 or IC51 325. (For corticosteroids, this would mean prednisone or equivalent at >0.05 mg/kg/day; topical and inhaled steroids are allowed).
Acute febrile infection at Visit 2 (only for the Booster Group).
Pregnancy (positive pregnancy test at Visit 1 and Visit 2), lactation or unreliable contraception in female subjects after onset of menarche.
Hypersensitivity reactions to IXIARO or adverse events in study IC51-323 requiring withdrawal from further vaccination or anaphylaxis or severe cases of atopy requiring emergency treatment or hospital admission during IC51-323 or IC51 325.
History of urticaria after hymenoptera envenomation, drugs, physical or other provocations or of idiopathic cause during IC51-323 or IC51 325.
Known infection with human immunodeficiency virus (HIV), hepatitis B virus (HBV) (measurement of Hepatitis B surface antigen [HBsAg] titers) or hepatitis C virus (HCV).
Illicit drug use and/or current drug or alcohol addiction.
Inability or unwillingness by the legal representative(s) and/or the subject (where applicable) to provide informed consent/assent and to abide by the requirements of the study.
Persons who have been committed to an institution (by a court or by an authority).

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
>14 months to <2 years	IXIARO	IXIARO 0.25 ml i.m. (milliliter, intramuscular)
>3 years - <18 years	IXIARO	IXIARO 0.5 ml i.m (milliliter, intramuscular)

Primary Outcome Measures

Name	Time	Method
SCRs (Seroconversion Rate) as Defined by Percentage of Subjects With Plaque Reduction Neutralization Test Titers of>1:10 at 1 Month After the Booster Dose	1 month post booster

Secondary Outcome Measures

Name	Time	Method
Rate of Subjects Achieving a >4-fold Increase in JEV (Japanese Encephalitis Virus) Neutralizing Antibody Titers at 1 Month After the Booster Dose	1 month
Rate of Subjects With Unsolicited AEs (Adverse Events) up to Months 12, 24 and 36 After the First IXIARO Vaccination in IC51 323 With and Without Booster Vaccination. Severity, Duration and Relationship to Vaccinations.	36 months
Rate of Subjects With SAEs and Medically Attended AEs Within 1 Month Following the Booster Dose. Severity, Duration and Relationship to Vaccinations.	1 month
Rate of Subjects With Unsolicited AEs Within 1 Month Following the Booster Dose. Severity, Duration and Relationship to Vaccinations.	1 month
GMTs (Geometric Mean Titre) for JEV Neutralizing Antibodies Measured Using a Validated PRNT (Plaque Reduction Neutralization Test) at 1 Month After the Booster Dose	1 month
GMTs and Rate of Subjects With a PRNT Titer of >1:10 at Months 12, 24 and 36 After First IXIARO Vaccination in IC51-323 With and Without Booster Vaccination	36 months
Rate of Subjects With SAEs (Serious Adverse Events) Following Immunization and Medically Attended AEs (Adverse Events) up to Months 12, 24 and 36 After the First IXIARO Vaccination in IC51 323 With and Without Booster Vaccination. Severity, Duration and	36 months
Rate of Subjects With Solicited AEs for up to 7 Days Following the Booster Dose. Severity and Duration.	7 days

Trial Locations

Locations (3): Research Institute for Tropical Medicine - Clinical Research Division
🇵🇭
Muntinlupa City, Alabang, Philippines
Research Institute for Tropical Medicine
🇵🇭
Muntinlupa City, Alabang, Philippines
UP-Philippine General Hospital
🇵🇭
Manila, Philippines