BARDA Awards Gritstone bio $433 Million Contract for Phase IIb Study of Next-Gen COVID-19 Vaccine

On Sept. 27, 2023, Gritstone bio, a clinical-stage biotechnology company, announced it has been awarded a contract by the Biomedical Advanced Research and Development Authority (BARDA) for the randomized Phase IIb study of its self-amplifying mRNA (samRNA) vaccine. The samRNA vaccine contains Spike antigen (similar to first-generation COVID-19 vaccines), as well as other viral targets to defend against COVID-19. The contract, valued at up to $433 million, is part of ‘Project NextGen’, a US Department of Health and Human Services (HHS) initiative that aims to push forward new and innovative vaccines and therapeutics providing larger and more long-lasting defenses for COVID-19.

As agreed upon in the contract, Gritstone bio is set to run a 10,000-participant, randomized Phase IIb double-blinded study that will compare its next-generation COVID-19 vaccine candidate against an approved COVID-19 vaccine. The study will test the immunogenicity, safety, and efficacy of the candidate, and it will be run in the United States alongside the COVID-19 Prevention Network (CoVPN). The CoVPN, which is supported by the National Institute of Allergy and Infectious Diseases (NIAID), is a network of clinical trial sites located at Fred Hutchinson Cancer Center with experience conducting large-scale COVID-19 vaccine trials.

This new vaccine candidate is a part of Gritstone bio’s CORAL program. The CORAL program uses self-amplifying mRNA and novel immunogens containing Spike antigen and additional viral targets to enhance B and T cell immunity. As of the publication of this article, the program has conducted three Phase I trials across a variety of patient populations and settings, including vaccine-naïve healthy and HIV+ subjects in South Africa, and healthy volunteers after primary series of approved COVID-19 vaccines. The results of these studies have showed high neutralizing antibody levels for at least six months and wide T cell responses. The CORAL program is supported by BARDA, NIAID, the Coalition for Epidemic Preparedness Innovations, and the Bill & Melinda Gates Foundation.

samRNA is a quickly emerging platform technology that can be used to develop multiple vaccines by changing the sequence of the antigen encoded in the vector RNA and delivered in a lipid nanoparticle. samRNA vaccines, much like traditional mRNA vaccines, use the translation system of the host to change mRNA to protein target antigens, encouraging immunity. But unlike mRNA, samRNA makes multiple copies of the antigen RNA once in the cell, which can lead to longer and amplified antigen expression.

Source: Gritstone Bio