NCT05067933

A Ph 2 Trial With an Oral Tableted COVID-19 Vaccine

A Phase 2, Double-Blind, Multi-Center, Randomized, Placebo-Controlled, Dose-Ranging Trial to Determine the Safety, Immunogenicity and Efficacy of an Adenoviral-Vector Based Vaccine Expressing Severe Acute Respiratory Syndrome (SARS-CoV-2) and dsRNA Adjuvant Administered Orally

• Status: Terminated
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 66 (actual)
• Sponsor: Vaxart · Industry
• Sex: All
• Age: 18 Years – 75 Years
• Healthy volunteers: Accepted

Summary

Part 1: An open label, dose and age escalation phase to evaluate the safety and immunogenicity of VXA-CoV2-1.1-S with a repeat-dose vaccination schedule in healthy adults aged 18 - 75 years old that are either vaccine naive or have received prior vaccination with an mRNA (messenger ribonucleic acid) vaccine for the prevention of COVID-19. Part 2: This phase will assess the efficacy of prophylactic VXA-CoV2-1.1-S against confirmed COVID-19 occurring from 7 days after second dose with a repeat-dose vaccination schedule in healthy adults compared to placebo. Safety and immunogenicity of VXA-CoV2-1.1-S will also be evaluated in this phase.

Detailed description

Part 1: This is an open-label, dose-ranging phase of the study to determine the safety and immunogenicity of an orally administered adenoviral-vector based vaccine (VXA-COV2-1.1-S) expressing a SARS-CoV-2 antigen and dsRNA adjuvant. Post screening activities, healthy adult volunteers, either naïve or prior vaccinated with an mRNA COVID-19 vaccine, aged 18 - 55 yrs old, and then 56 - 75 yrs old, will be enrolled into the study in 8 subgroups. Participants will receive either a low or a high dose of an oral tableted vaccine at Days 1 and Day 29. The total study period will last \~ 2 months during the active phase, with a total 12 month safety follow-up period post last vaccination. Safety, reactogenicity and immunogenicity assessments will be performed at set times during the study active and follow-up periods. Subjects will be monitored for symptoms of COVID-19 throughout the duration of the study follow-up period. An independent data monitoring committee (IDMC) will provide safety oversight through the duration of the trial. Safety and immunogenicity data will inform on the dose selection for Part 2. Part 2: This will be a placebo-controlled phase with the vaccine dose level selected from Part 1. Subjects will receive two doses of vaccine or placebo at Days 1 and 29. Subjects will be followed as in Part 1 for safety and immunogenicity. They will also be followed for 6 months for efficacy.

Conditions

• COVID-19

Interventions

Type	Name	Description
DRUG	VXA-CoV2-1.1-S	COVID-19 (SARS-CoV-2) E1-/E3-Deleted Replication Defective Recombinant Adenovirus 5 with dsRNA Adjuvant Oral Tablet Vaccine
OTHER	Placebo Tablets	Placebo tablets matching the active vaccine tablets

Timeline

• Start date: 2021-10-22
• Primary completion: 2022-06-10
• Completion: 2023-05-09
• First posted: 2021-10-05
• Last updated: 2025-04-13
• Results posted: 2025-04-13

Locations

4 sites across 1 country: United States

Regulatory

• FDA-regulated drug study