Gritstone presents 6-month follow up data on Phase 1 CORAL-CEPI, CORAL-BOOST

Gritstone bio presented 6-month follow up data from its ongoing Phase 1 CORAL-CEPI and CORAL-BOOST studies, which are evaluating the company’s self-amplifying mRNA vaccine candidates against SARS-CoV-2, at the 33rd European Congress of Clinical Microbiology & Infectious Diseases in Copenhagen, Denmark. CORAL-CEPI Presentation: Study of Self-Amplifying mRNA Vaccine Candidates Against COVID-19 in Healthy Adults and People Living with Human Immunodeficiency Virus in South Africa. Key Highlights: CORAL-CEPI is the first study assessing a samRNA-based vaccine in vaccine-naive populations in South Africa; All doses of GRT-R914 were well tolerated in all study populations evaluated to date; IgG and nAb levels to SpikeWT and variants of concern Beta and Delta are induced or boosted by GRT-R914 administration and maintained for 6 months; Majority of post-vaccine T cell responses observed to TCE epitopes focused on NSP and Nucleocapsid, irrespective of prior SARS-CoV-2 exposure; Previous SARS-CoV-2 exposure does not affect T cell responses post vaccination in both naive and convalescent populations. CORAL-BOOST Presentation: First study of a Self-amplifying mRNA Vaccine, GRT-R910, as a COVID-19 Boost in Healthy Volunteers greater than or equal to60 years of age – Preliminary evidence of sustained immunogenicity. Key Highlights: CORAL-BOOST is the first study assessing a samRNA-based SARS-CoV-2 vaccine as a booster following adenoviral- or mRNA-based primary vaccination series in a more vulnerable older population; GRT-R910 was as well tolerated at all dose levels; GRT-R910 increased SpikeWT-specific IgG levels regardless primary series of immunization; Consistent longevity of neutralizing antibody response for at least 6 months against different variants of concern not included in the vaccine construct; GRT-R910 increased breadth of T cell responses against Spike and non-Spike T cell epitopes included in the vaccine.