Gritstone bio and CEPI Expand Vaccine Agreement to Tackle Omicron Variant

Gritstone bio, Inc., a clinical-stage biotechnology company developing next generation cancer and infectious disease immunotherapies, and CEPI, the Coalition for Epidemic Preparedness Innovations, announced the expansion of their agreement in order to support the development of a self-amplifying mRNA (SAM) vaccine designed to tackle the Omicron COVID-19 variant. CEPI will provide up to $5 million in additional funding to conduct a Phase 1 clinical trial of Gritstone’s Omicron vaccine candidate in South Africa, where a CEPI-funded clinical trial of Gritstone’s Beta variant COVID-19 vaccine is due to begin shortly. The SARS-CoV-2 T cell epitopes (TCEs) administered within Gritstone’s SAM COVID-19 vaccines are minimally impacted by mutations found within the Omicron variant, reinforcing the platform’s potential to address both Omicron and future variants of concern.

CEPI is already funding up to $20.6 million to support preclinical studies, manufacturing process optimization, and a Phase 1 trial of Gritstone’s Beta variant vaccine candidate (containing beta-Spike plus additional TCEs), which will be initiated by South Africa’s University of the Witwatersrand in the coming weeks. The funding announced today will expand the Phase 1 trial to include additional arms to evaluate an Omicron-specific version of the vaccine (which contains omicron-Spike plus TCEs). Gritstone has commenced manufacturing its SAM vaccine to specifically target the Omicron variant, and the Omicron arms of the Phase 1 trial are expected to begin in Q2 2022, subject to regulatory approval.

The recently described Omicron variant, first identified in South Africa on November 9, 2021, was designated a variant of concern by the World Health Organization (WHO) on November 26, 2021. Early evidence suggests that Omicron carries an increased risk of re-infection, and sequence analysis has revealed many mutations in Spike, which may reduce clinical effectiveness of existing vaccines and/or therapeutic antibodies.