A Controlled Phase 2/3 Study of Adjuvanted Recombinant SARS-CoV-2 Trimeric S-protein Vaccine (SCB-2019) for the Prevention of COVID-19

Phase 2

Completed

• Conditions: COVID-19
• Interventions: Biological: CpG 1018/Alum-adjuvanted SCB-2019 vaccine; Biological: Placebo; 0.9% saline; Biological: SCB-2019 vaccine; Biological: SCB-2019 vaccine for Placebo

• Registration Number: NCT04672395
• Lead Sponsor: Clover Biopharmaceuticals AUS Pty Ltd

Brief Summary

The purpose of this double-blind, randomized, controlled study is to evaluate the efficacy, immunogenicity, reactogenicity and safety of an adjuvanted recombinant severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) trimeric spike (S)-protein subunit vaccine (SCB-2019) for the prevention of SARS-CoV-2-mediated COVID-19 in Participants Aged 12 Years and Older.

Detailed Description

This study will assess the efficacy against COVID-19, immunogenicity, reactogenicity, and safety of CpG 1018/Alum-adjuvated SCB-2019 vaccine. The COVID-19 pandemic has resulted in high morbidity and mortality, caused major disruption to healthcare systems, and has had significant socioeconomic impacts. Currently, only limited treatment options are available against COVID-19 and accelerated vaccine development is urgently needed. Several COVID-19 vaccines were recently authorized in some countries, but the global supply is insufficient for pandemic control. Additional safe and effective vaccines for COVID-19 prevention would have significant public health impact.

Placebo recipients will be offered two doses of SCB-2019 vaccine at defined points as part of the study.

Adults participants who received SCB-2019 vaccine, will be given a third dose of the SCB-2019 vaccine at least 4 months after the second dose to assess the safety and efficacy of a booster (third) dose.

Study Timeline

• Study First Submitted: 2020-12-16
• Study First Submitted QC: 2020-12-16
• Study First Posted: 2020-12-17
• Study Start: 2021-03-24
• Primary Completion: 2022-09-15
• Study Completion: 2023-04-23
• Status Verified: 2023-06
• Last Update Submitted: 2023-06-28
• Last Update Posted: 2023-06-29

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 31454

Inclusion Criteria

1. Male or females ≥12 years of age, inclusive*.

2. Participants who are willing and able to comply with study requirements, including all scheduled visits, vaccinations, laboratory tests, the electronic completion of the COVID-19 ePRO and other study procedures.

3. Healthy adult or adolescent subjects or adult or adolescent subjects with pre-existing medical conditions who are in stable condition. A stable medical condition is defined as disease not requiring significant change in therapy or hospitalization for worsening disease during the 3 months before enrollment.

   *Note: The first 200 individuals enrolled in the Phase 2 part of the study should be healthy subjects 18 to 64 years or age without comorbidities associated with a high risk of severe COVID-19

4. Female subjects who are WOCBP are eligible to participate in the study if not pregnant, not breastfeeding, and at least 1 of the following criteria apply:

   • WOCBP must have a negative urine pregnancy test prior to each vaccination. A confirmatory serum pregnancy test may be conducted at the investigator's discretion.
   • They must be using a highly effective licensed method of birth control for 30 days prior to the first vaccination and must agree to continue such precautions during the study until 90 days after the second vaccination.

5. Male subjects must agree to employ acceptable contraception from the day of first dose of the study vaccine/placebo until 6 months after the last dose of the study vaccine/placebo and also refrain from donating sperm during this period.

6. Individuals (or their legally acceptable representative based on local regulations) willing and able to give an informed consent, prior to screening. For adolescent subjects: informed assent signed by adolescents and informed consent signed by the parent(s) or legally acceptable representative(s) as per local requirements.

7. Applicable for HIV-positive individuals only if:

They are medically stable at screening, as determined by the investigator, and free of opportunistic infections in the 1 year prior to first study vaccination, and They have an HIV-1 viral load <1000 copies/mL within 45 days of randomization in the study, and They are receiving highly active antiretroviral therapy (HAART) for at least 3 months before screening. Changes in antiretroviral dosage within 3 months of entering the study are allowed, as are exchanges in pharmacological formulations.

Exclusion Criteria

1. Individuals with laboratory-confirmed SARS-CoV-2 infection (e.g., a positive RT-PCR* or Rapid COVID-19 Antigen test) at screening or within 14 days prior to enrollment.
2. Individuals with behavioral or cognitive impairment (including drug and alcohol abuse) in the opinion of the investigator.
3. Individuals with any progressive or severe neurologic disorder, seizure disorder, or history of Guillian-Barré syndrome.
4. Individuals who receive treatment with immunosuppressive therapy, including cytotoxic agents or systemic corticosteroids, e.g., for cancer or an autoimmune disease, or planned receipt during the study period.
5. Individuals who are pregnant, or breastfeeding, or planning to become pregnant during the study period.
6. Individuals who have a history of severe adverse reaction associated with a vaccine or severe allergic reaction (e.g., anaphylaxis) to any component of the study vaccine (SCB-2019, CpG1018 Adjuvant and Aluminum hydroxide components).
7. Individuals who have a history of malignancy within 1 year before screening (exceptions are squamous and basal cell carcinomas of the skin and carcinoma in situ of the cervix which have been cured, or other malignancies with minimal risk of recurrence).
8. Individuals who have received any other investigational product within 30 days prior to Day 1 or intent to participate in another clinical study at any time during the conduct of this study.
9. Individuals who have received previous vaccination with any coronavirus vaccine.
10. Individuals who have received any other licensed vaccines within 14 days prior to enrollment in this study or who are planning to receive any vaccine up to 14 days after the second vaccination.
11. Individuals with known bleeding disorder that would, in the opinion of the investigator, contraindicate intramuscular injection.
12. Individuals who received any blood/plasma products or immunoglobulins within 60 days prior to Day 1 or plan to receive it during the study period.
13. Individuals with any condition that, in the opinion of the investigator, may increase the risk of study participation or interfere with the assessment of the primary study objectives.
14. Individuals with fever >37.8°C (irrespective of method), or any acute illness at baseline (Day 1) or within 3 days of randomization.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Group 1	CpG 1018/Alum-adjuvanted SCB-2019 vaccine	CpG 1018/Alum-adjuvanted SCB-2019 vaccine
Group 2	Placebo; 0.9% saline	Placebo Comparator: 0.9% Saline
Booster dose of SCB-2019	SCB-2019 vaccine	Adult SCB-2019 recipients will receive 1 dose of SCB-2019 at least 4 months after the second dose
Vaccination of placebo recipients with SCB-2019	SCB-2019 vaccine for Placebo	Placebo participants will be offered two doses of SCB-2019 vaccine

Primary Outcome Measures

Name	Time	Method
Number of Participants with Unsolicited AEs	Up to Day 43 (21 days after each dose)
Number of Participants with a First Occurrence of COVID-19 of Any Severity Starting 14 Days after Second Dose of SCB-2019	Day 36 up to Day 389 (1 year after second dose)
Number of Participants with Serious Adverse Events (SAEs), or Medically Attended AEs (MAAEs), or AEs Leading to Early Termination, or Adverse Events of Special Interest (AESIs)	Up to Day 389 (1 year after second dose)
Number of Participants with Solicited Local and Systemic Adverse Reactions (ARs)	Up to Day 8 (7 days after first dose) and up to Day 29 (7 days after second dose)
Non-inferiority of the neutralizing titers after third dose compared to the neutralizing titers after second dose	14 days after third dose
Non-inferiority of the neutralising titers in adolescents versus young adults.	14 days after second dose

Secondary Outcome Measures

Name	Time	Method
Number of Participants with a First Occurrence of Moderate-to-Severe COVID-19 Starting 14 Days after Second Dose of SCB-2019	Day 36 up to Day 389 (1 year after second dose)
Number of Participants with a First Occurrence of Severe COVID-19 Starting 14 Days after Second Dose of SCB-2019 or Placebo	Day 36 up to Day 389 (1 year after second dose)
Geometric Mean Titer (GMT) of SARS-CoV-2 Specific nAb	Day 1A, Day 15A (15 days after booster), and Day 389A (6 months after booster)
Number of Participants with a First Occurrence of COVID-19 Starting 14 days after Second Dose of SCB-2019 or Placebo, regardless of risk of severe COVID-19	Day 36 up to Day 389 (1 year after second dose)
Number of Participants with a First Occurrence of COVID-19 Starting 14 days after First Dose of SCB-2019 or Placebo	Day 15 up to Day 22
Geometric Mean Fold Rise (GMFR) of SARS-CoV-2 Specific nAb	Day 1A, Day 15A (15 days after booster), and Day 389A (6 months after booster)
Geometric Mean Fold Rise (GMFR) of SCB-2019 binding antibody	Day 1A, Day 15A (15 days after booster), and Day 389A (6 months after booster)
Geometric Mean Titer (GMT) of Trimer-Tag binding antibody	Day 1, Day 22, Day 35, Day 205, and Day 389
Number of Participants with Solicited Local and Systemic Adverse Reactions (ARs)	Up to 7 days after booster dose
Number of Participants with Serious Adverse Events (SAEs), or Medically Attended AEs (MAAEs), or AEs Leading to Early Termination, or Adverse Events of Special Interest (AESIs)	Up to 6 months after booster dose
Number of Participants with First Occurrence of Any Laboratory-Confirmed Asymptomatic SARS-CoV-2 infection Starting 14 Days after Second Dose of SCB-2019 or Placebo	Day 36 up to Day 389 (1 year after second dose)
Geometric Mean Titer (GMT) of SARS-CoV-2 antibodies competing for binding of S protein to the human ACE2 receptor	Day 1, Day 22, Day 35, Day 205, and Day 389
Geometric Mean Fold Rise (GMFR) of SARS-CoV-2 antibodies competing for binding of S protein to the human ACE2 receptor	Day 1, Day 22, Day 35, Day 205, and Day 389
Number of Participants with a First Occurrence of COVID-19 of Any Severity, Associated with Hospitalization, Starting 14 Days after Second Dose of SCB-2019 or Placebo	Day 36 up to Day 389 (1 year after second dose)
Number of Participants with a First Occurrence of COVID-19 Starting 14 days after Second Dose of SCB-2019 or Placebo, regardless of evidence of prior SARS-CoV-2 Infection	Day 36 up to Day 389 (1 year after second dose)
Geometric Mean Titer (GMT) of SARS-CoV-2 Specific Neutralizing Antibody (nAb)	Day 1, Day 22, Day 35, Day 205, and Day 389
Number of Participants with Seroconversion for SARS-CoV-2 Specific nAb	Day 1A, Day 15A (15 days after booster), and Day 389A (6 months after booster)
Number of Participants with Seroconversion for SCB-2019 binding antibody	Day 1A, Day 15A (15 days after booster), and Day 389A (6 months after booster)
Number of Participants with First Occurrence of Any Laboratory-Confirmed SARS-CoV-2 infection Starting 14 Days after Second Dose of SCB-2019 or Placebo	Day 36 up to Day 389 (1 year after second dose)
Burden of Disease Score of COVID-19 or SARS-CoV-2 Infection Cases Starting 14 Days after Second Dose of SCB-2019 or Placebo	Day 36 up to Day 389 (1 year after second dose)
Number of Participants with a First Occurrence of COVID-19 of Any Severity caused by SARS-CoV-2 variants of concern starting 14 days after Second Dose	Day 36 up to Day 389 (1 year after second dose)
Number of Participants with Seroconversion for of SARS-CoV-2 antibodies competing for binding of S protein to the human ACE2 receptor	Day 1, Day 22, Day 35, Day 205, and Day 389
Geometric Mean Titer (GMT) of SCB-2019 binding antibody	Day 1A, Day 15A (15 days after booster), and Day 389A (6 months after booster)
Geometric Mean Fold Rise (GMFR) of Trimer-Tag binding antibody	Day 1, Day 22, Day 35, Day 205, and Day 389
Number of Participants with Unsolicited AEs	Up to 21 days after booster dose

Trial Locations

Locations (31)

Centro de Estudios en Infectología Pediátrica S.A.S. - CEIP S.A.S.; 🇨🇴 Cali, Colombia

University of the East Ramon Magsaysay Memorial Medical Center; 🇵🇭 Quezon City, Philippines

Private Practice RESPISOM Namur; 🇧🇪 Namur, Belgium

UERM Memorial Medical Center; 🇵🇭 Quezon City, Philippines

CPCLIN - Centro de Pesquisas Clínicas de Natal; 🇧🇷 Natal, Rio Grande Do Norte, Brazil

Hospital de Clínicas de Porto Alegre; 🇧🇷 Porto Alegre, Rio Grande Do Sul, Brazil

Hospital da Universidade Federal de Santa Maria CEP/UFSM; 🇧🇷 Santa Maria, Rio Grande Do Sul, Brazil

Instituto Atena de Pesquisa Clinica; 🇧🇷 Natal, Rio Grande Do Norte, Brazil

Anima; 🇧🇪 Alken, Belgium

Instituto D'OR de Pesquisa e Ensino; 🇧🇷 Rio de Janeiro, Rio Do Janeiro, Brazil

Hôspital Erasme; 🇧🇪 Bruxelles, Belgium

Centro de Atención e investigación Médica S.A.S, CAIMED S.A.S - sede, Acacias; 🇨🇴 Acacías, Colombia

Clínica de la Costa Ltda; 🇨🇴 Barranquilla, Colombia

Fundación Hospital Universitario del Norte; 🇨🇴 Barranquilla, Colombia

Centro de Atención e investigación Médica S.A.S, CAIMED S.A.S - sede, Bogotá D.C.; 🇨🇴 Bogotá, Colombia

Centro de Atención e investigación Médica S.A.S, CAIMED S.A.S - sede Aguazul; 🇨🇴 Aguazul, Colombia

Policlinico Social del Norte; 🇨🇴 Bogotá, Colombia

IPS Médicos Internistas de Caldas SAS; 🇨🇴 Manizales, Colombia

Centro de Atención e investigación Médica S.A.S, CAIMED S.A.S - sede, Yopal; 🇨🇴 Yopal, Colombia

De La Salle Medical and Health Sciences Institute; 🇵🇭 Dasmariñas, Cavite, Philippines

Las Pinas Doctors Hospital; 🇵🇭 Las Piñas, Philippines

Tropical Disease Foundation; 🇵🇭 Makati, Philippines

Manila Doctors Hospital; 🇵🇭 Manila, Philippines

Asian Hospital and Medical Center; 🇵🇭 Muntinlupa, Philippines

University of the Philippines Manila - Philippine General Hospital; 🇵🇭 Pasay, Philippines

FEU-NRMF Medical Center; 🇵🇭 Quezon City, Philippines

Wits Clinical Research; 🇿🇦 Johannesburg, Gauteng, South Africa

St. Luke's Medical Center; 🇵🇭 Taguig, Philippines

DJW Research; 🇿🇦 Krugersdorp, Gauteng, South Africa

Soweto Clinical Trials Centre; 🇿🇦 Soweto, Gauteng, South Africa

Dr JM Engelbrecht Trial Site; 🇿🇦 Somerset West, Western Cape, South Africa