NCT05626803

A Study to Determine the Safety and Immunogenicity of Bivalent GI.1 and GII.4 Vaccines in Healthy Volunteers

A Phase 2, Multicenter, Randomized, Double-blind, Placebo-controlled, Single Dose, Dose-ranging Study to Determine the Safety and Immunogenicity of Bivalent GI.1 and GII.4 Vaccine Administered Orally to Healthy Volunteers Aged Greater Than or Equal to 18 Years and Less Than or Equal to 80 Years Old.

• Status: Completed
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 135 (actual)
• Sponsor: Vaxart · Industry
• Sex: All
• Age: 18 Years – 80 Years
• Healthy volunteers: Accepted

Summary

This study is designed to evaluate the safety and immunogenicity of two monovalent Norovirus (NoV) oral tableted vaccine candidates, VXA-G1.1-NN and VXA-GII.4-NS co-administered (bivalent delivery) against a matching placebo arm. Bivalent GI.1 and GII.4 vaccines are being investigated for the prevention of noroviral gastroenteritis caused by norovirus GI.1 and GII.4.

Detailed description

Norovirus infections are a leading cause of sporadic and epidemic gastroenteritis across all age groups worldwide. This study is designed as a standard double-blind placebo-controlled single administration, dose ranging study to evaluate the safety and immunogenicity of 2 different doses of VXA-GII.4-NS plus VXA-G1.1-NN (high and medium dose administered orally for the prevention of Norovirus infection), compared with a placebo. This study will enroll a total of 135 subjects with10 sentinel subjects in an open label period (dosing staggered to not-more-than 2 subjects per 24 hours) and randomize 125 subjects in three arms. The first 10 sentinel subjects will receive the open label high dose of active vaccine. If no dose-related toxicities are observed, and upon the recommendation of the SMC following review of safety data, subjects will be randomized in a 2:2:1 ratio to one of the 3 study arms to receive active vaccine or placebo. After vaccination on Day 1, the study will include an Active Study Period that runs through 4 weeks after administration (Day 29), and a Follow-up Period of one year for safety and duration of immune response.

Conditions

• Norovirus Infections

Interventions

Type	Name	Description
DRUG	Open label Bivalent GII.4/GI.1 high dose vaccine 2×10 to the power 11 IU/dose	The first 10 sentinel subjects will receive open label high dose of active vaccine. Bivalent GII.4/GI.1 high dose vaccine (VXA-GII.4-NS plus VXA-G1.1-NN) 1×10 to the power 11 tablets; total dose is 2×10 to the power 11 IU/dose
DRUG	Bivalent GII.4/GI.1 high dose vaccine 2×10 to the power 11 IU/dose	50 subjects will receive high dose of active vaccine. Bivalent GII.4/GI.1 high dose vaccine (VXA-GII.4-NS plus VXA-G1.1-NN) 1×10 to the power 11 tablets; total dose is 2×10 to the power 11 IU/dose
DRUG	Bivalent GII.4/GI.1 medium dose vaccine 1×10 to the power 11 IU/dose	50 subjects will receive Bivalent GII.4/GI.1 medium dose vaccine (VXA-GII.4-NS plus VXA-G1.1-NN) 5×10 to the power 10 tablets; total dose is 1×10 to the power 11 IU/dose
DRUG	Placebo	25 subjects will receive matching placebo

Timeline

• Start date: 2023-01-26
• Primary completion: 2023-10-16
• Completion: 2023-10-16
• First posted: 2022-11-25
• Last updated: 2025-04-15
• Results posted: 2025-04-15

Locations

3 sites across 1 country: United States

Regulatory

• FDA-regulated drug study