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A Phase 3b/4 Randomised Trial of 3 Doses of Protein-based Covid-19 Vaccine (SpikoGen)

Phase 3
Active, not recruiting
Conditions
COVID-19
Interventions
Biological: Advax-CpG55.2 adjuvanted recombinant spike protein
Registration Number
NCT05279456
Lead Sponsor
Vaxine Pty Ltd
Brief Summary

This study will determine the immunogenicity of Spikogen in vaccine naïve individuals. Spikogen will be administered as two doses 1 month apart with a third booster dose either 1 or 3 months after the second dose. This study will provide key data on SARS-CoV-2 antibody responses.

Detailed Description

The SARS-CoV-2 outbreak has caused millions of deaths globally. It has a particularly high mortality rate in elderly people and those with chronic disease where mortality rates can be as high as 20-30%. SARS-COV-2 vaccines remain a key priority to help fight the current pandemic. COVID-19 vaccines prevent symptomatic infection and may help reduce virus transmission. Spikogen® vaccine, also known as Covax-19™ in Australia, is an adjuvanted recombinant protein Covid-19 vaccine has recently been approved by the Iranian FDA for emergency use in Iran in adults as a primary vaccine course and booster dose, after meeting its primary efficacy endpoint in a Phase 3 trial in 16,876 participants randomised 3:1 to receive Spikogen vaccine or saline placebo via two intramuscular doses 3 weeks apart where Spikogen vaccine demonstrated significant protection against serious infection with the delta variant. Approximately 5-10% of the broader Australian population and an even higher proportion of the indigenous populations remains unvaccinated despite current availability of these vaccines. One reason is that some people have medical contraindications to the current vaccines, such as serious allergies to the vaccine components such as polyethyleneglycol (PEG) in the mRNA vaccines.

Spikogen vaccine is made using a recombinant protein approach with the SARS-CoV-2 spike protein synthesized in an insect cell line grown in broth. Insect cell expression of recombinant protein is a well-established vaccine manufacturing approach. Spikogen vaccine also contains a unique Australian developed adjuvant called Advax-CpG55.2, which is added to the spike protein to make the vaccine more effective. AdvaxCpG55.2 has two components, one a natural plant sugar called inulin, and the second a short synthetic oligonucleotide polymer, known as CpG55.2 oligonucleotide.

Spikogen vaccine is designed to protect against SARS-CoV-2 infection. It has been shown to be effective against infection in hamster, ferret and monkey SARS-CoV-2 infection models.

This study will determine the immunogenicity of Spikogen in vaccine-naïve individuals. Spikogen will be administered as two doses 31 month apart with a third booster dose given either 1 or 3 months after the second dose.

Recruitment & Eligibility

Status
ACTIVE_NOT_RECRUITING
Sex
All
Target Recruitment
39
Inclusion Criteria
  • Able to provide written informed consent
  • Males or females* 18 years of age or older
  • Understand and are likely to comply with planned study procedures and be available for all study visits.
  • Have not previously had a Covid-19 vaccine and do not intend to have a non-study Covid-19 vaccine within the next 6 months
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Exclusion Criteria
  • History of Covid-19 vaccination.
  • History of serious vaccine allergy.
  • Pregnancy1
  • Have received an experimental agent within 30 days prior to the study vaccination or expect to receive another experimental agent during the trial reporting period.
  • Any medical, social or mental condition which, in the opinion of the investigator, would be detrimental to the subjects or the study.
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Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Spikogen vaccine - accelerated armAdvax-CpG55.2 adjuvanted recombinant spike proteinSpikogen vaccine 25 micrograms by intramuscular injection on study months 0, 1 and 2
Spikogen vaccine - standard armAdvax-CpG55.2 adjuvanted recombinant spike proteinSpikogen vaccine 25 micrograms by intramuscular injection on study months 0, 1 and 4
Primary Outcome Measures
NameTimeMethod
Serious adverse events (SAE)through study completion, an average of 7 months

Number of Serious adverse events (SAE) occurring within study period in each group stratified by baseline antibody positivity

First Dose Adverse events (AE)7 days post first immunisation

AE occurring within 7 days of immunisation in each group stratified by baseline antibody positivity

First dose Seroconversion2-4 weeks post first immunisation

Proportion of subjects in each group stratified by baseline antibody positivity seroconverting to spike protein antibody positivity

Second dose Seroconversion2-4 weeks post second immunisation

Proportion of subjects in each group stratified by baseline antibody positivity seroconverting to spike protein antibody positivity

Third Dose Seroconversion2-4 weeks post third immunisation

Proportion of subjects in each group stratified by baseline antibody positivity seroconverting to spike protein antibody positivity

Final Seroconversionthrough study completion, an average of 7 months

Proportion of subjects in each group stratified by baseline antibody positivity seroconverting to spike protein antibody positivity

Second Dose GMT2-4 weeks post second immunisation

Spike protein antibody Geometric Mean Titers (GMT) in each group stratified by baseline antibody positivity

Final GMTthrough study completion, an average of 7 months

Spike protein antibody Geometric Mean Titers (GMT)in each group stratified by baseline antibody positivity

First Dose GMT2-4 weeks post first immunisation

Spike protein antibody Geometric Mean Titers (GMT) in each group stratified by baseline antibody positivity

Third Dose GMT2-4 weeks post third immunisation

Spike protein antibody Geometric Mean Titers (GMT)in each group stratified by baseline antibody positivity

Second Dose Adverse events (AE)7 days post second immunisation

AE occurring within 7 days of immunisation in each group stratified by baseline antibody positivity

Third Dose Adverse events (AE)7 days post third immunisation

AE occurring within 7 days of immunisation in each group stratified by baseline antibody positivity

Secondary Outcome Measures
NameTimeMethod
Seroconversion against variants of concern2-4 weeks post first, second and third immunisation and at study completion

Serum spike protein antibody seroconversion rates against each SARS-CoV-2 variant of concern in trial participants in each group stratified by baseline antibody positivity

First dose Vaccine efficacyFrom 2 weeks post-first dose to 2 weeks after second dose

Proportion of Covid-19 infections in trial participants in each group stratified by baseline antibody positivity

Second dose Vaccine efficacyFrom 2 weeks post-second dose to 2 weeks after third dose

Proportion of Covid-19 infections in trial participants in each group stratified by baseline antibody positivity

GMT against variants of concern2-4 weeks post first, second and third immunisation and at study completion

Geometric mean serum spike protein antibodies against SARS-CoV-2 variants in trial participants in each group stratified by baseline antibody positivity

Third dose Vaccine efficacyFrom 2 weeks post-third dose through study completion, an average of 7 months

Proportion of Covid-19 infections in trial participants in each group stratified by baseline antibody positivity

Total Covid-19 infectionsFrom first vaccine dose through study completion, an average of 7 months

Proportion of breakthrough Covid-19 infections in trial participants in each group stratified by baseline antibody positivity

Trial Locations

Locations (1)

ARASMI

🇦🇺

Adelaide, South Australia, Australia

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