As the coronavirus variants continue to intensify the ongoing pandemic, Gritstone bio is advancing its second-generation Covid-19 vaccine, and now Financing The Alliance for Epidemic Prevention Innovation (CEPI) supports more clinical trials.
Gritstone has reached an agreement with CEPI to provide up to US$20.6 million in funding to bring its vaccine to the first phase of testing initially conducted in South Africa. Combined with the biotech company’s own phase 1 testing, the company said that it has four candidates being evaluated for vaccination against young people, the elderly, people who have previously been vaccinated, and immunocompromised patients. If the Gritstone vaccine works in the South African study, it will be available globally through the COVAX program of the World Health Organization.
Emeryville, California-based Gritstone calls its second-generation Covid vaccine program CORAL. Like the first-generation Covid vaccine, Gritstone’s vaccine candidate is providing spike proteins to trigger an immune response. But the biotech company’s vaccines also provide other parts of “conserved” antigens, which means they will not change much as the virus mutates. Vaccines that target conserved regions of the virus make it more likely to remain effective when the virus changes.
The CORAL vaccine is delivered to cells via chimpanzee adenovirus, self-amplified mRNA, or both. Self-amplifying messenger RNA (SAM) is composed of RNA encoding the target antigen and RNA polymerase. RNA polymerase is an enzyme that copies DNA sequences into RNA sequences during the transcription process. Gritstone vaccine is administered as an intramuscular injection. The company stated in its regulatory documents that after the vaccine is absorbed by the patient’s cells, the RNA is translated into protein, and RNA polymerase begins to copy the RNA in the injection, thereby amplifying the RNA copy in the cell. Therefore, a large number of target antigens are produced. Gritstone said that unlike mRNA vaccines, its SAM vaccine produces a large number of antigens, which in turn drives a strong T cell response.
“We believe that Gritstone’s CORAL vaccine candidate may improve the response of T cells and antibodies to Spike and other viral proteins,” the company said in its statement. 2020 Annual Report“In addition, by targeting several viral antigens, some of which are highly conserved among virus strains (such as SARS and SARS-CoV-2), we believe that our candidate vaccine may have pan-SARS/coronavirus potential to prevent future Of the coronavirus pandemic.”
The first phase of the planned study in South Africa will evaluate two SAM vaccines, each targeting the spike protein and other parts of the virus. Both vaccines are designed to cause a strong response of B cells and T cells. Gritstone expects to start this research by the end of this year. According to the terms of the agreement announced on Tuesday, CEPI will provide funding for this multi-arm study, which will evaluate vaccines and HIV for uninfected individuals, currently healthy subjects who have previously been infected with SARS-CoV-2 and convalescent subjects based on antibody tests. Positive patients.
In March, a separate phase 1 study supported by the National Institute of Allergy and Infectious Diseases began to administer drugs to patients. Gritstone expects this study to report data in the fourth quarter of this year. In addition, Gritstone is preparing a company-sponsored clinical trial to evaluate CORAL as a booster for Covid vaccines currently authorized for emergency use and vaccines with weaker immune systems.
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