NCT06615375

A Human Challenge Study to Assess Protection of a Shigella Tetravalent Bioconjugate Vaccine

Phase 2b, Double-blind, Placebo-controlled Efficacy Challenge Study With the Shigella Tetravalent Bioconjugate Vaccine Shigella4V2

• Status: Active Not Recruiting
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 120 (estimated)
• Sponsor: LimmaTech Biologics AG · Industry
• Sex: All
• Age: 18 Years – 50 Years
• Healthy volunteers: Accepted

Summary

In this challenge study, the bioconjugate candidate vaccine Shigella4V2 will be tested for its ability to induce an immune response that protects healthy adult volunteers from infection with a wild-type Shigella sonnei strain compared to participants receiving placebo.

Detailed description

The tetravalent Shigella4V2 bioconjugate vaccine candidate will be tested for safety and preliminary efficacy in a Phase 2b controlled human infection model (CHIM) study at three sites in the United States. This trial will be conducted as a parallel-group, randomized, double-blind, multicenter, placebo-controlled study to evaluate the safety, immunogenicity, and efficacy of two injections of Shigella4V2 in healthy Shigella naïve participants 18-50 years of age, with the second injection administered one month before challenge with S. sonnei 53G strain. It will have two steps: 1. Step 1, a dose confirmation step, in which a first injection of Shigella4V2 (high dose or low dose, adjuvanted with Alhydrogel) will be administered alongside a placebo arm (phosphate-buffered saline) at a ratio of 2:2:1. A second injection of either Shigella4V2 low dose or placebo will be administered about 6 months after the first injection. 2. Step 2, in which participants will be randomized to the Shigella4V2 dose selected after Step 1 or to placebo at a ratio of 1:1. Participants will receive two injections, 28 days apart. One month after the second injection, they will be challenged with 1500 CFU of the virulent Shigella sonnei strain 53G.

Conditions

• Shigellosis

Interventions

Type	Name	Description
BIOLOGICAL	Shigella4V2	Shigella4V2 is a tetravalent bioconjugate vaccine
BIOLOGICAL	Placebo	Phosphate-buffered saline

Timeline

• Start date: 2024-11-12
• Primary completion: 2026-04-01
• Completion: 2026-09-01
• First posted: 2024-09-26
• Last updated: 2026-04-13

Locations

3 sites across 1 country: United States

Regulatory

• FDA-regulated drug study