Gritstone bio Inc. (NASDAQ: GRTS) has shared encouraging Phase 1 clinical findings from cohort 1 (10 µg dose of CORAL self-amplifying mRNA (samRNA) vaccine) of the CORAL-BOOST study, showing both robust CD8+ T cell response and neutralizing antibody response to Spike.
Gritstone increases dose in CORAL-BOOST study to 30 mg
Gritstone’s CORAL program is working on a second-generation COVID-19 vaccine that will drive both strong neutralizing antibodies and trigger widespread CD8+ T cell immunity in recognition of the increased attention on T cell immunity as a significant means of protection against existing and future Spike variants.
CORAL-BOOST is one of four trials in AstraZeneca’s CORAL program that is assessing the reactogenicity, immunogenicity, and safety of a samRNA vaccine aimed directly against Spike and evolutionarily conserved non-Spike T cell epitopes as a booster against COVID-19 in healthy adults aged 60 years and older that have previously received the first two doses of AstraZeneca’s vaccine. The CORAL-BOOST Phase 1 trial is still running in the United Kingdom, and the dose has now been increased to 30 mg as planned.
CEO co-founder and President of Gritstone Andrew Allen, said, “We are thrilled to share that our T cell-enhanced samRNA vaccine from the CORAL program is driving both robust CD8+ T cell responses to a broad array of viral epitopes and strong neutralizing antibody responses to Spike, which we believe validates the potential of our infectious disease platform. As we have seen with the Omicron variant, viral surface proteins such as Spike are mutating at a high rate, leaving the immunity provided by Spike-dedicated vaccines vulnerable to variants containing numerous Spike mutations.”
Gritstone designed vaccines to driver wider CD8+ T cell immunity
Allen added, “We designed our COVID-19 vaccines to drive broad CD8+ T cell immunity, an additional key layer of protection against viruses. This innovation enables inclusion of a wide array of highly conserved viral epitopes, potentially creating an immune state that may offer more robust clinical protection against current and future SARS-CoV-2 variants and be a first step toward developing a pan-coronavirus vaccine.”