Safety and Immunogenicity of the Japanese Encephalitis Vaccine IC51 (IXIARO®) in a Pediatric Population

Valneva Austria GmbH1,869 enrolled

Overview

The primary objective is to assess the systemic and local safety profile of purified inactivated Japanese Encephalitis Virus (JEV) vaccine IC51 administered in two doses in a 28 days interval up to Month 7 after the first IC51 vaccination in a pediatric population from endemic regions.

Open-label, randomized, active controlled Phase 3 study in children aged ≥ 2 months to \< 18 years. Subjects aged ≥ 2 months to \< 12 months were randomized in a 2:1 ratio to receive IC51 (0.25 ml dose) or Prevnar® as a safety comparator. Children aged ≥ 12 months to \< 3 years and ≥ 12 years to \< 18 years were randomized in a 3:1 ratio to receive IC51 (0.25 ml dose \< 3 years, 0.5 ml ≥ 12 years) or HAVRIX®720 as safety comparator. For subjects aged ≥ 3 years to \< 12 years, a dose finding run-in phase was performed. A total of 200 subjects were randomized 1:1 to receive either the 0.25 ml or the 0.5 ml dose of IC51, and the appropriate dose was determined based on an interim analysis. After this run-in phase, 300 further children in this age group were randomized 2:1 to receive either 0.5 ml of IC51 or HAVRIX®720. Immunogenicity was be studied in a subgroup of 30 children aged ≥ 2 months to \< 12 months; 125 children aged ≥ 12 months to \< 3 years and 140 children ≥ 12 years to \< 18 years. For the age group of ≥ 3 to \< 12 years immunogenicity was assessed in the 200 children enrolled during the dose-finding run-in phase.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

NONE

Enrollment

1,869

Conditions

Encephalitis

Interventions

IC51 Japanese EncephalitisBIOLOGICAL

6 mcg or 3 mcg im. at day 0 and day 28

Havrix®720BIOLOGICAL

0.5 ml im. at day 0 and month 7

PrevnarBIOLOGICAL

0.5 ml im. at day 0 and day 56 and month 7

Eligibility

Sex: ALLMin age: 2 MonthsMax age: 18 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Male or female healthy children and adolescents aged \> 2 months to \< 18 years at the time of first vaccination. * 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, for females after menarche willingness to practice a reliable method of contraception. Exclusion Criteria: * Clinical manifestation of Japanese Encephalitis * History of Flavivirus vaccination (including any investigational vaccines) * History of vaccination with HAVRIX®720 and/or Prevnar® * History of immunodeficiency or immunosuppressive therapy * Known HIV, HBV or HCV infection * History of hypersensitivity reactions to other vaccines * Acute febrile infection at each visit during which the subject receives a vaccination * Active or passive immunization within 2 weeks prior to the first IC51 vaccination and up to the second IC51 vaccination.

Locations (2)

Research Institute for Tropical Medicine

City of Muntinlupa, Filinvest Corporate City, Philippines

Department of Pediatrics, UP-Philippine General Hospital

Manila, Philippines

Outcomes

Primary Outcomes

Rate of Subjects With Serious Adverse Events and Medically Attended Adverse Events Until Day 56 After First Vaccination

Rate of subjects with these types of AEs, comparison vs respective control vaccine stratified by age group: All study participants aged \< 1 year: IC51 0.25mL vs. Prevnar; All study participants aged 1 year and above: IC51 0.25 mL or =.5 mL vs. Havrix.

Time frame: until Day 56

Secondary Outcomes

Geometric Mean Titers (GMT) for JEV Neutralizing Antibodies

GMT for JEV neutralizing antibodies is presented per dose group rather than age group due to overlapping age groups. IC51 0.25 mL includes subjects aged 2 months to \< 12 years; IC51 0.5 mL includes subjects aged ≥ 3 years to \< 18 years.

Time frame: Day 0, 56 and at Month 7

Seroconversion Rate (SCR) at Days 0, 56 and at Month 7

Seroconversion was defined as a PRNT50 titer of at least 1:10. SCRs are presented per dose group rather than age group due to overlapping age groups. IC51 0.25 mL includes subjects aged 2 months to \< 12 years; IC51 0.5 mL includes subjects aged ≥ 3 years to \< 18 years.

Time frame: Days 0, 56 and at Month 7

Rate of Subjects With SAEs and Medically Attended AEs

Rate of subjects with SAEs and medically attended AEs; For this analysis IC51 vaccine recipients are displayed by age group rather than by dose group. This allows comparison of the safety profile of IC51 with the active control for the respective age group: Prevnar for study participants aged \>= 2 months to \<1 year and Havrix 720 for study participants aged \>= 1 year.

Time frame: up to Month 7

Rate of Subjects With Solicited Local and Systemic AEs

Rate of subjects with solicited local and systemic AEs. Solicited AEs of local and systemic tolerability, i.e., reactions at the injection site or systemic reactions typical for vaccinations, were to be evaluated for 7 consecutive days after each vaccination (except after the HAVRIX®750 and Prevnar® injections at Month 7 \[Visit 4\]) and recorded in the subject diary. For this analysis IC51 vaccine recipients are displayed by age group rather than by dose group. This allows comparison of the safety profile of IC51 with the active control for the respective age group: Prevnar for study participants aged \>= 2 months to \<1 year and Havrix 720 for study participants aged \>= 1 year.

Data from ClinicalTrials.gov

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