Challenge studies in immunized non-human primates has shown the vaccine offers ‘robust protection’ against the virus.
The candidate is dubbed a 'second-generation' vaccine thanks to its simple storage and transportation requirements: retaining its potency at 37˚ C / 95˚ F for a week, and being shelf-stable for four months at 25 ˚C / 77 ˚F (the vaccine should be refrigerated for long-term storage). It is also inexpensive to produce – a single 2,000 liter production line could be capable of producing over one billion doses a year.
Fighting the RBD
The vaccine, AKS-452, is based on Akston’s proprietary Fc fusion protein platform. It is designed to induce or boost a Th1/Th2 mixed immune response in patients against the Receptor Binding Domain (RBD) on the novel coronavirus’ spike protein.
Being the primary locus for infection, the RBD is highly conserved among mutated variants of the virus, and preclinical studies have also shown robust antibody neutralization of the B.1.1.7 (‘UK’) and B.1.351 (‘South Africa’) variants.
The Phase I/II clinical trial, an open-label study, will involve 176 healthy volunteers aged 18-65. Participants will receive one dose, or two doses 28 days apart, and the study will assess three-dose levels (22.5, 45, and 90 micrograms) to determine safety, tolerability and immune response in each regimen.
The trial is managed by TRACER Europe B.V., a CRO specializing in fast-track clinical trials; and is being conducted at the University Medical Center Groningen (UMCG), one of the largest hospitals in the Netherlands.
“This is an important milestone in meeting the worldwide need for a next-generation vaccine against the SARS-CoV2 virus, one that is stable for months at ambient temperatures and can be quickly manufactured at very large scale,” said Todd Zion, Ph.D., President & CEO of Akston Biosciences.
“If proven safe and efficacious, AKS-452 promises to become an affordable and easily transportable vaccine that can speed the goal of achieving herd immunity, considering 93% of the world still has not been vaccinated. We believe that this is a vaccine for everywhere and everyone in the world.”
In January, Akston established a strategic partnership with LakePharma, a US-based Biologics CRDMO with operations in CA, TX, and MA, to produce drug substance for the Phase 3 clinical trial as well as large-scale commercial manufacturing.
Akston expects the Phase 1 and 2 readouts in Q2 and Q3 respectively: with a phase 3 read-out in Q4 2021. The first submission for regulatory authorization would be in the EU.
The vaccine
Based on Akston’s proprietary Fc fusion protein platform, AKS-452 is a CoV-2 subunit vaccine designed to induce or boost a Th1/Th2 mixed immune response in patients against the Receptor Binding Domain (RBD) of the novel coronavirus spike protein.
The Fc moiety aids in delivering the vaccine to antigen-presenting cells via binding to the Fc-γ receptor, and subsequent antigen processing and presentation to CD4+ T-cells.
Directing the immune system against the RBD instead of the entire spike protein may be the most efficient way to prevent viral attachment and infection with minimal side effects.