Gritstone bio Delays Phase 2b COVID-19 Vaccine Trial for GMP Compliance

Gritstone bio, a clinical-stage biotechnology firm, has announced a change in the timeline for its Phase 2b trial of a next-generation COVID-19 vaccine. Originally planned for the first quarter of 2024, the trial will now commence in the fall of the same year. This adjustment is to incorporate fully Good Manufacturing Practice (GMP)-grade materials, which are expected to enhance the trial's regulatory value.

Andrew Allen, MD, PhD, Gritstone's Co-founder, President, and CEO, explained that the decision to utilize GMP-grade materials was made following discussions with the FDA and input from the Biomedical Advanced Research and Development Authority (BARDA). This change is anticipated to not only increase the regulatory significance of the study but also to improve its interpretability and address the most recent seasonal variants of the virus.

The CORAL-BARDA study is designed to be a randomized, double-blinded trial involving 10,000 participants. It aims to compare the efficacy, safety, and immunogenicity of Gritstone's self-amplifying mRNA (samRNA) vaccine candidate against an already approved COVID-19 vaccine. The objective is to ascertain if the samRNA vaccine can offer superior and more enduring protection against the virus.

Self-amplifying mRNA (samRNA) technology is gaining prominence as a scalable and adaptable platform for vaccine development. It allows for the creation of various vaccines by simply altering the antigen sequence encoded in the vector RNA. samRNA vaccines, like traditional mRNA vaccines, utilize the host cell's translation system to convert mRNA into protein antigens, thereby stimulating an immune response. However, samRNA vaccines have the advantage of producing multiple copies of the antigen RNA within the cell, which could lead to a more sustained and potent antigen expression.

Gritstone's innovative approach to vaccine development involves designing novel immunogens and including both Spike and non-Spike antigens to elicit a robust immune response. This "Spike plus" strategy is believed to induce strong, long-lasting neutralizing antibodies and broad, durable T cell immunity, while also being potent at lower doses and maintaining stability at refrigerator temperatures.

Gritstone bio is dedicated to developing potent vaccines and advancing a pipeline of product candidates to combat viral diseases and solid tumors, with the goal of improving patient outcomes and eradicating diseases. The company's efforts are supported by federal funds from the U.S. Department of Health and Human Services and BARDA, under a specific contract number.

It is important to note that the development and regulatory process for new vaccines is complex and involves numerous uncertainties. These include the inherent challenges in drug development, the regulatory approval process, and the manufacturing of drug products, among other factors. Gritstone's ability to establish, protect, and defend its intellectual property also plays a crucial role in the success of its research and clinical development programs.