Gritstone Advances Second Generation COVID-19 Vaccine

Gritstone Oncology is advancing development of a second-generation vaccine against SARS-CoV-2, the virus that causes COVID-19, with potential for both prolonged protection and potency against Spike mutants. Gritstone and the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH), have entered into a clinical trial agreement to initiate clinical testing. A Phase 1 clinical trial, expected to be conducted through the NIAID-supported Infectious Diseases Clinical Research Consortium (IDCRC), is in development. The Bill & Melinda Gates Foundation (Gates Foundation) is supporting the preclinical evaluation of the vaccine.

Through a license agreement with the La Jolla Institute for Immunology (LJI), one of the leading global organizations dedicated to studying the immune system, Gritstone has access to validated SARS-CoV-2 epitopes that have been identified through LJI’s studies of hundreds of patients recovering from COVID-19. Using these epitopes and the company’s proprietary Gritstone EDGETM and vaccine platform technologies, Gritstone is developing a novel vaccine against COVID-19, containing Spike (similar to first generation vaccines) but also additional viral epitopes that offer good targets for T cell immunity. Gritstone uses both self-amplifying mRNA and adenoviral vectors to deliver the SARS-CoV-2 viral antigens. The vaccine may have pan-SARS/coronavirus potential to protect against future coronavirus pandemics.

“Gritstone’s vaccine may provide more comprehensive viral protection by inducing a better combination of T cell responses and neutralizing antibodies as compared to the currently available vaccines,” said Daniel Hoft, M.D., Ph.D., director of Saint Louis University’s Center for Vaccine Development and Division of Infectious Diseases, Allergy and Immunology, National Vaccine Advisory Committee member, and protocol chair and lead principal investigator of Gritstone’s COVID study. “It is important that we move forward with developing these next generation vaccines because we do not yet know whether the existing vaccines that have been granted emergency use authorization will provide long-term immunity or prevent transmission. Improved vaccines that can accomplish these additional benefits may be needed to continue mitigating the ongoing pandemic.”

The company has received a grant from the Gates Foundation to support the preclinical evaluation of the vaccine. NIAID is supporting development of the Phase 1 clinical trial through the IDCRC.

“Since inception, Gritstone has developed two core assets – cutting-edge T cell epitope identification and potent vaccines shown to activate a strong and broad immune response in humans – and both of these have been deployed in our quest for a second-generation SARS-CoV-2 vaccine,” said Andrew Allen, M.D., Ph.D., co-founder, president and chief executive officer of Gritstone. “We are excited to be working with the experienced teams at NIAID and the IDCRC as well as the experts at the Gates Foundation and LJI who have helped us design and pre-clinically test our novel vaccine concepts.”

“Our preclinical work has shown that our SARS-CoV-2 vaccines can induce sustained, high-titer neutralizing antibodies and CD8+ T cell responses against the Spike protein, plus a broad CD8+ T cell response against epitopes from multiple viral genes outside of Spike. As well as a potential role in protection against SARS-CoV-2, the notion of using evolutionarily conserved viral antigens (in addition to Spike) as the basis for a vaccine that induces antibody and T-cell responses to provide protection against future coronavirus pandemics is an exciting concept that springs from our current work. We plan to pursue this in 2021,” Karin Jooss, Ph.D., chief scientific officer at Gritstone, said.