A Study of S-268019 for the Prevention of COVID-19

A Phase 3, Randomized, Observer-Blind, Placebo- Controlled Cross-over Study to Evaluate the Efficacy, Safety, and Immunogenicity of S-268019 for the Prevention of COVID-19

The main purpose of this study is to assess the efficacy of S-268019-b for the prevention of COVID-19 in the initial vaccination period prior to crossover in participants without evidence of infection before vaccination as compared to placebo.

Study Overview

• Status: Completed
• Conditions: SARS-CoV-2
• Intervention / Treatment: Drug: S-268019-b; Drug: Placebo

Detailed Description

Eligible participants will be randomized to receive either S-268019-b or placebo first and then will be crossed over to receive the opposite intervention. The study will consist of two treatment periods, an initial vaccination period (Day 1 to Day 224), and a crossover vaccination period (Day 225 to Day 435).

• Study Type: Interventional
• Enrollment (Actual): 9902
• Phase: Phase 3

Contacts and Locations

Study Locations

• Vietnam
  • Dak Lak
    • Buon Ma Thuot City, Dak Lak, Vietnam
      • Buon Ma Thuot City Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Agree not to participate in any other SARS-CoV-2 prevention trial during the study follow-up.
• Capable of using Diary without difficulties (if applicable, with assistance by caregiver).

Exclusion Criteria:

• Current or history of a laboratory-confirmed diagnosis of SARS-CoV-2 infection or COVID-19.
• Unstable current cardiovascular, respiratory, hepatic, renal, gastrointestinal, endocrine, hematological, or neurological disease that, in the opinion of the investigator or subinvestigator, would constitute a safety concern or confound data interpretation.
• Immunosuppression (immunodeficiency, acquired immunodeficiency syndrome [AIDS], use of systemic steroids, use of immunosuppressants within the past 6 months prior to the first dose of study intervention, treatment for malignant tumors, other immunosuppressive therapy).
• Previous vaccination against SARS-CoV-2.
• Any inactivated vaccine received within 14 days prior to the first dose of study intervention.
• Any live vaccine received within 28 days prior to the first dose of study intervention.
• Immunoglobulin preparations, blood products, or a blood transfusion within 3 months prior to the first dose of study intervention.

Other inclusion and exclusion criteria may apply.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: S-268019-b, Then Placebo; Participants will first receive a dose of S-268019-b via intramuscular (IM) injection on Day 1 and Day 29 during the initial vaccination period. After the initial vaccination period, participants will then receive a placebo IM injection (matching S-268019-b) on Day 225 and Day 253.	Drug: S-268019-b; Solution for IM injection; Drug: Placebo; Saline solution for IM injection
Experimental: Placebo, Then S-268019-b; Participants will first receive a dose of placebo IM injection (matching S-268019-b) on Day 1 and Day 29 during the initial vaccination period. After the initial vaccination period, participants will then receive S-268019-b IM injection on Day 225 and Day 253.	Drug: S-268019-b; Solution for IM injection; Drug: Placebo; Saline solution for IM injection

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Number of Participants With First Occurrence of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Reverse Transcription Polymerase Chain Reaction (RT-PCR)-Positive Symptomatic COVID-19 in the Initial Vaccination Period	14 days after the second dose administration

Secondary Outcome Measures

Outcome Measure	Time Frame
Number of Participants With First Occurrence of SARS-CoV-2 RT-PCR-Positive Severe COVID-19 in the Initial Vaccination Period with Onset at Least 14 Days Following Second Vaccination	14 days after the second dose administration
Number of Participants With First Occurrence of SARS-CoV-2 RT-PCR-Positive Symptomatic COVID-19 in the Initial Vaccination Period	Up to Day 224
Number of Participants With First Occurrence of SARS-CoV-2 RT-PCR-Positive Severe COVID-19 in the Initial Vaccination Period	Up to Day 224

Collaborators and Investigators

• Sponsor: Shionogi

Study record dates

Study Major Dates

• Study Start (Actual): December 25, 2021
• Primary Completion (Actual): December 19, 2022
• Study Completion (Actual): July 19, 2023

Study Registration Dates

• First Submitted: January 24, 2022
• First Submitted That Met QC Criteria: January 24, 2022
• First Posted (Actual): January 28, 2022

Study Record Updates

• Last Update Posted (Actual): July 25, 2023
• Last Update Submitted That Met QC Criteria: July 24, 2023
• Last Verified: July 1, 2023

More Information

Terms related to this study

• Other Study ID Numbers: 2126U0232

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No