NCT05073003

A Study on the Safety and Immune Responses to the GVGH altSonflex1-2-3 Vaccine Against Shigellosis in Adults, Children, and Infants

A Staged Phase I/II Observer-blind, Randomised, Controlled, Multi-country Study to Evaluate the Safety, Reactogenicity, and Immune Responses to the GVGH altSonflex1-2-3 Vaccine Against S. Sonnei and S. Flexneri, Serotypes 1b, 2a, and 3a, in Adults in Europe (Stage 1) Followed by Age De-escalation From Adults to Children and Infants, and Dose-finding in Infants in Africa (Stage 2)

• Status: Completed
• Phase: Phase 1
• Study type: Interventional
• Enrollment: 551 (actual)
• Sponsor: GlaxoSmithKline · Industry
• Sex: All
• Age: 9 Months – 50 Years
• Healthy volunteers: Accepted

Summary

The aim of the current clinical study is to evaluate, for the first time in humans (FTIH), the safety and immunogenicity of the altSonflex1-2-3 candidate vaccine against S. sonnei and S. flexneri serotypes 1b, 2a, and 3a. The vaccine will be first administered in adults 18 to 50 years of age in Europe. Subsequently, the vaccine will be administered to a shigellosis-endemic population in Africa, first in adults 18 to 50 years of age, then in children 24 to 59 months of age, finally in infants 9 months of age. Infants will also receive a third vaccination. Three different doses of the vaccine \[low (Dose A), medium (Dose B), and high (Dose C) amounts of antigen\] will be evaluated using an age de-escalation approach (from least vulnerable adult population to most vulnerable paediatric population). The results of this study will allow the selection of the most appropriate dose for further vaccine development in infants 9 months of age, which is the main target age group for this vaccine.

Conditions

• Diarrhoea

Interventions

Type	Name	Description
DRUG	altSonflex Placebo	2 doses of altSonflex Placebo, administered intramuscularly, in the non-dominant arm, either at Day 1 and Day 85 or at Day 1 and Day 169 (depending on the vaccination schedule) to adults in the ST1\_Adults\_Placebo\_GR1 and ST1\_Adults\_Placebo\_GR2 groups in Stage 1 (Europe).
BIOLOGICAL	altSonflex1-2-3 Dose C	2 doses of altSonflex1-2-3 Dose C administered intramuscularly, in the non-dominant arm, at Day 1 and Day 85 to adults in the ST1\_Adults\_Dose C\_GR1 and ST2\_Adults\_Dose C groups in Stage 1 and 2 (Europe and Africa) and children in the ST2\_Children\_Dose C group in Stage 2 (Africa), and at Day 1 and Day 169 to adults in the ST1\_Adults\_Dose C\_GR2 group in Stage 1 (Europe); 3 doses of altSonflex1-2-3 Dose C administered intramuscularly, in the non-dominant arm, at Day 1, Day 85 and Day 253 to infants in the ST2\_Infants\_Dose C\_Safety and ST2\_Infants\_Dose C\_Dose find groups in Stage 2 (Africa).
BIOLOGICAL	altSonflex1-2-3 Dose B	2 doses of altSonflex1-2-3 Dose B administered intramuscularly, in the non-dominant arm, at Day 1 and Day 85 to children in the ST2\_Children\_Dose B group in Stage 2 (Africa); 3 doses of altSonflex1-2-3 Dose B administered intramuscularly, in the non-dominant arm, at Day 1, Day 85 and Day 253 to infants in the ST2\_Infants\_Dose B\_Safety and ST2\_Infants\_Dose B\_Dose find groups in Stage 2 (Africa).
BIOLOGICAL	altSonflex1-2-3 Dose A	3 doses of altSonflex1-2-3 Dose A administered intramuscularly, in the non-dominant arm, at Day 1, Day 85 and Day 253 to infants in the ST2\_Infants\_Dose A\_Safety and ST2\_Infants\_Dose A\_Dose find groups in Stage 2 (Africa).
BIOLOGICAL	GSK's Meningococcal A, C, Y and W-135 conjugate vaccine	1 dose of GSK's Meningococcal A, C, Y and W-135 conjugate vaccine administered intramuscularly, in the non-dominant arm, at Day 1 to adults in the ST2\_Adults\_Control C group and children in the ST2\_Children\_Control B and ST2\_Children\_Control C groups in Stage 2 (Africa); 2 doses of GSK's Meningococcal A, C, Y and W-135 conjugate vaccine administered intramuscularly, in the non-dominant arm, at Day 1 and Day 85 to infants in the ST2\_Infants\_Control A\_Safety, ST2\_Infants\_Control B\_Safety, ST2\_Infants\_Control C\_Safety and ST2\_Infants\_Control\_Dose find groups in Stage 2 (Africa).
COMBINATION_PRODUCT	GSK's Tetanus toxoid, reduced diphtheria toxoid and acellular pertussis vaccine	1 dose of GSK's Tetanus toxoid, reduced diphtheria toxoid and acellular pertussis vaccine administered intramuscularly, in the non-dominant arm, at Day 85 to adults in the ST2\_Adults\_Control C group in Stage 2 (Africa).
COMBINATION_PRODUCT	GSK's Diphtheria, tetanus, pertussis, hepatitis B, poliomyelitis (inactivated), and Haemophilus influenzae type b vaccine	1 dose of GSK's Diphtheria, tetanus, pertussis, hepatitis B, poliomyelitis (inactivated), and Haemophilus influenzae type b vaccine administered intramuscularly, in the non-dominant arm, at Day 253 to infants in the ST2\_Infants\_Control A\_Safety, ST2\_Infants\_Control B\_Safety, ST2\_Infants\_Control C\_Safety and ST2\_Infants\_Control\_Dose find groups in Stage 2 (Africa).
COMBINATION_PRODUCT	Sanofi Pasteur's Typhoid Vi polysaccharide vaccine	1 dose of Sanofi Pasteur's Typhoid Vi polysaccharide vaccine administered intramuscularly, in the non-dominant arm, at Day 85 to children in the ST2\_Children\_Control B and ST2\_Children\_Control C groups in Stage 2 (Africa).
BIOLOGICAL	Serum Institute of India's Measles and rubella vaccine	2 doses of Serum Institute of India's Measles and rubella vaccine administered subcutaneously, in the non-dominant arm, at Day 29 and Day 281 to infants in the safety groups, and at Day 1 and Day 253 to infants in the dose-finding groups, in Stage 2 (Africa).

Timeline

• Start date: 2021-10-06
• Primary completion: 2025-06-24
• Completion: 2025-06-24
• First posted: 2021-10-11
• Last updated: 2025-12-04

Locations

2 sites across 2 countries: Belgium, Kenya