Efficacy, Safety and Immunogenicity Study of GlaxoSmithKline(GSK) Biologicals' Candidate Malaria Vaccine 257049 in the Sporozoite Challenge Model in Healthy Malaria-naïve Adults

Malaria Clinical Trial

Official title: Efficacy, Safety and Immunogenicity Study of GSK Biologicals' Candidate Malaria Vaccine 257049 in the Sporozoite Challenge Model in Healthy Malaria-naïve Adults

Status Completed

Clinical Trial Summary

This study is designed to evaluate safety, reactogenicity, immunogenicity, and efficacy of GSK Biological's malaria candidate vaccine 257049 administered as standard doses at 0 and 1 months and 1/5th standard dose at 7 months (delayed fractional dose group) and 257049 administered as three standard doses one month apart (0, 1, 2-month group) in healthy malaria-naïve volunteers aged 18-50 years in the sporozoite challenge model.

An additional, delayed sporozoite challenge will assess persistence of protection induced by the primary immune schedule and if an additional dose can provide protection in those unprotected by the initial vaccination series.

Clinical Trial Description

This protocol posting has been amended to reflect changes in Amendment 1 of the Protocol (20 April 2014).

Rationale for Protocol Amendment 1:

• In order to assess whether protection is maintained over time, and assess boostability, the protocol has been amended to incorporate another sporozoite challenge, after a single boost of 1/5th standard dose of RTS,S/AS01B, or no boost.

Study design:

• Dependent upon enrolment date during the screening period, the study duration will be approximately 19 months for each vaccinated subject in the delayed fractional dose group, 14 months for each vaccinated subject in the 0, 1, 2-month group, 7 months for each infectivity control subject in the challenge phase and 6 months for each infectivity control subject in the rechallenge phase.

• Vaccination schedules:

• 0, 1, 7-month followed by sporozoite challenge 21 days (3 weeks) after the third vaccination, with subsequent boosting/no boosting at Booster Phase Study Day 0 followed by sporozoite rechallenge 3 weeks post boost/no boost.

• 0, 1, 2-month followed by sporozoite challenge 21 days (3 weeks) after the third vaccination, with subsequent boosting/no boosting at Booster Phase Study Day 0 followed by sporozoite rechallenge 3 weeks post boost/no boost.

• Safety and immunogenicity will be evaluated during the study up to 3 months after rechallenge (Booster Phase Study Day 105).

• Treatment allocation:

• Non-randomized for primary phase; subjects will be enrolled to different study groups in a consecutive manner, to ensure the day of sporozoite challenge (conducted over two days) is the same for all.

• For the booster and rechallenge phase, subjects unprotected during the first challenge will receive a 1/5th RTS,S/AS01B booster dose while subjects from each group who were protected in the first challenge will be randomized to receive a 1/5th RTS,S/AS01B booster dose or no booster dose.

This protocol posting has been amended to reflect changes in Amendment 2 of the Protocol (08 January 2015) Rationale for Protocol Amendment 2: In order to have sufficient blood samples for future assay development or testing, evaluation of Hepatitis B (HBs) cellular-mediated immunogenicity (CMI) was de-prioritised from a secondary outcome measure to a tertiary secondary outcome measure and will only be conducted if sufficient cells are available from the thawn cryotube(s) that will be used for circumsporozoite protein (CS) testing. ;

Related Conditions & MeSH terms

• Malaria

• NCT number: NCT01857869
• Study type: Interventional
• Source: GlaxoSmithKline
• Status: Completed
• Phase: Phase 2
• Start date: May 20, 2013
• Completion date: December 16, 2014