NCT05911087

A Phase II/III Study to Evaluate the Immunogenicity and Safety and Efficacy of SWIM816 Vaccines for SARS-CoV-2

A Phase 2/3, Randomized, Double-blinded , Parallel Controlled Trial to Evaluate the Immunogenicity, Safety and Efficacy of A Heterologous Booster Dose With COVID-19 mRNA Vaccines (Bivalent) , in Previously Vaccinated Subjects Against COVID-19 With 2/3 Doses COVID-19 Vaccine Compared to a Booster Dose With mRNA COVID-19 Vaccine（Pfizer Bivalent Vaccine）in Adults.

• Status: Unknown
• Phase: Phase 2 / Phase 3
• Study type: Interventional
• Enrollment: 800 (estimated)
• Sponsor: Stemirna Therapeutics · Industry
• Sex: All
• Age: 18 Years
• Healthy volunteers: Accepted

Summary

Primary Immunogenicity Objective：Cohort 1: GMTs of SARS-CoV-2 Omicron and related strain neutralizing antibody levels for SWIM816.Cohort 2: To demonstrate the non- inferiority of neutralizing antibody response in terms of geometric mean titers (GMT) of COVID-19 mRNA vaccine(SWIM816) compare with mRNA COVID-19 vaccine(Pfizer Bivalent vaccine) 14 days post dose. Primary Safety Objective：To assess the reactogenicity and safety of a booster dose in a heterologous vaccination regimen in subjects previously immunized with 2/3 doses of COVID-19 vaccine with or without previously diagnosed with COVID-19. Secondary Immunogenicity Objectives：To describe the neutralizing antibody response at D29, D91 and D181.To describe binding antibody profile at D01, D15, D29, D91 and D181 of each study group. Secondary Safety Objective：To assess the reactogenicity and safety of third or fourth booster dose in a heterologous vaccination regimen in subjects previously immunized with 2/3 COVID-19 vaccine doses. Exploratory Objective：1.Documented confirmed SARS-CoV-2 symptomatic infection；2.Todemonstrate the cellular immune response profile at study group (30 subjects per each group for cellular immune testing).

Detailed description

Endpoints: Cohorts 1: GMT of SARS-CoV-2 Omicron (such as BA.5, BQ.1,XBB) and reference strain neutralizing antibody(Delta and other circulating strain) levels for SWIM816 on D15 after study vaccination. Cohorts 1: GMFR of SARS-CoV-2 Omicron (such as BA.5, BQ.1, XBB) and reference strain neutralizing. antibody (other circulating strain) levels for SWIM816 on D15 after study vaccination. Cohorts 1: % of participants with seroresponse to SWIM816 for GMTs of SARS-CoV-2 Omicron(such as BA.5, BQ.1, XBB) and reference strain neutralizing antibody (other circulating strain) levels on D15 after study vaccination. Cohorts 2 (≥18 years ) Non-inferiority analysis: Geometric Mean Ratio (GMR) of SARS-CoV-2 Omicron (such as BA.5, BQ.1,XBB)-neutralizing antibody (other circulating strain) levels for SWIM816 to Pfizer Bivalent vaccine on D15 after study vaccination. Endpoints: Occurrence of local and systemic AEs reported within 7 days after study vaccination. Occurrence of unsolicited AEs reported within 28 days after vaccination. Frequency, severity and relatedness of adverse events within 28 days after vaccination booster dose. Endpoints: Cohorts 1+2 : GMTs of Pseudovirus SARS-CoV-2 Omicron (such as BA.5, BQ.1,XBB) and reference strain neutralizing antibody levels for SWIM816 before and on D29, D91, D181 after study vaccination. Cohorts 1+2 : GMFR of SARS-CoV-2 Omicron (such as BA.5, BQ.1,XBB) and reference strainneutralizingantibody levels for SWIM816 before and on D29, D91, D181 after study vaccination. Cohorts 1: % of participants with seroresponse to SWIM816 for GMTs of SARS-CoV-2 Omicron(such as BA.5, BQ.1, XBB) and reference strain neutralizing antibody (other circulating strain) levels on D29, D91, D181 after study vaccination. Cohorts 1 : GMTs and GMI of IgG profile at D01, D15, D29 , D91and D181 of each study group. Cohorts 1: GMTs of Pseudovirus SARS-CoV-2 Omicron (such as BA.5, BQ.1,XBB) and reference strain neutralizing antibody levels for SWIM516 before and on D15, D29, D91, D181 after study vaccination. Cohorts 1: GMFR of SARS-CoV-2 Omicron (such as BA.5, BQ.1,XBB) and reference strain neutralizing antibody levels for SW-BIC-213 before and on D15, D181 after study vaccination. Endpoints: Serious AEs (SAEs), AEs leading to withdrawal and AEs of special interest (AESIs) within 180 days. Endpoints: Occurrence of confirmed symptomatic cases during the study period. Number of confirmed SARS-CoV-2 symptomatic cases; Severity of confirmed cases of SARS-CoV-2 infection(WHO scale). Number of IFN-γ positive (characterizing Th1) and IL-4 positive (characterizing Th2) T cell subsets on D8 and Day 15 \[ Time Frame: Day 8 and Day 15 after the study vaccination .\]

Conditions

• Immunogenicity
• Safety

Interventions

Type	Name	Description
BIOLOGICAL	Phase II:SWIM816;SARS-Cov-2;	The study will be performed in people who were previously vaccinated with 2/3 doses of COVID-19 vaccine, with or without previously diagnosed with COVID-19. The interval between the date of last dose and the date of this study vaccination should be 6 to 24 months. There are 2 groups in phase 2 stage, total number 200 subjects who are ≥18 years old. Details as below: Group 1: (N=100) - SWIM816 25 μg; Group 2: (N=100) - SW-BIC-213 25 μg;
BIOLOGICAL	Phase II:SW-BIC-213;SARS-Cov-2;	The study will be performed in people who were previously vaccinated with 2/3 doses of COVID-19 vaccine, with or without previously diagnosed with COVID-19. The interval between the date of last dose and the date of this study vaccination should be 6 to 24 months. There are 2 groups in phase 2 stage, total number 200 subjects who are ≥18 years old. Details as below: Group 1: (N=100) - SWIM816 25 μg; Group 2: (N=100) - SW-BIC-213 25 μg;
BIOLOGICAL	PhaseIII:SWIM816;SARS-Cov-2;	The study will be performed in people who were previously vaccinated with 2/3 doses of COVID-19 vaccine, with or without previously diagnosed with COVID-19. The interval between the date of last dose and the date of this study vaccination should be 6 to 24 months. There are two groups in phase 3 stage., total number 600 subjects who are ≥18 years old. Details as below: Group 1: (N=300) - SWIM816 (≥18 years old ) Group 2: (N=300) -Pfizer Bivalent vaccine (≥18 years old)
BIOLOGICAL	PhaseIII:Pfizer(Pfizer Bivalent vaccine);SARS-Cov-2；	The study will be performed in people who were previously vaccinated with 2/3 doses of COVID-19 vaccine, with or without previously diagnosed with COVID-19. The interval between the date of last dose and the date of this study vaccination should be 6 to 24 months. There are two groups in phase 3 stage., total number 600 subjects who are ≥18 years old. Details as below: Group 1: (N=300) - SWIM816 (≥18 years old ) Group 2: (N=300) -Pfizer Bivalent vaccine (≥18 years old)

Timeline

• Start date: 2023-06-20
• Primary completion: 2023-07-31
• Completion: 2024-02-01
• First posted: 2023-06-20
• Last updated: 2023-06-20