Clinical development of SpikoGen®, an Advax-CpG55.2 adjuvanted recombinant spike protein vaccine.

ABSTRACT

Recombinant protein vaccines represent a well-established, reliable and safe approach for pandemic vaccination. SpikoGen® is a recombinant spike protein trimer manufactured in insect cells and formulated with Advax-CpG55.2 adjuvant. In murine, hamster, ferret and non-human primate studies, SpikoGen® consistently provided protection against a range of SARS-CoV-2 variants. A pivotal Phase 3 placebo-controlled efficacy trial involving 16,876 participants confirmed the ability of SpikoGen® to prevent infection and severe disease caused by the virulent Delta strain. SpikoGen® subsequently received a marketing authorization from the Iranian FDA in early October 2021 for prevention of COVID-19 in adults. Following a successful pediatric study, its approval was extended to children 5 years and older. Eight million doses of SpikoGen® have been delivered, and a next-generation booster version is currently in development. This highlights the benefits of adjuvanted protein-based approaches which should not overlook when vaccine platforms are being selected for future pandemics.

SpikoGen is a more traditional COVID-19 vaccine comprising SARS-CoV-2 spike protein extracellular domain formulated with Advax-CpG adjuvantSpikoGen differs from the Novavax vaccine in major ways including its use of the soluble secreted spike protein ECD rather than nanoparticle formulation and the use of a different adjuvantSpikoGen demonstrates robust protection against homologous and heterologous SARS-CoV-2 strains in hamster, ferret and non-human primate challenge modelsSpikoGen induces broadly cross-neutralizing antibodies, but still protects even after these antibody levels waneIn a pivotal Phase 3 clinical trial, SpikoGen reduced the risk of severe infection by 77.5% and was not associated with myocarditis, thrombosis or any other adverse safety signalsSpikoGen received an Emergency Use Authorization in the Middle East on 6 October 2021, making it the first recombinant spike protein vaccine to achieve this milestoneEight million doses of SpikoGen vaccine have been safely delivered to dateProtein-based vaccines have a long history of reliability and safety.