The human adenovirus (hAd5) vector vaccine candidate has been designed to target both the inner nucleocapsid (N) and outer spike (S) proteins, said ImmunityBio.
The N-protein has been designed to activate T cells, while S-protein has been engineered to activate antibodies against the novel coronavirus (SARS-CoV-2).
ImmunityBio has designed the second-generation adenoviral vector platform to generate immune response even in patients with pre-existing adenovirus immunity.
The dual constructs (bivalent sequences) of SARS-CoV-2 is said to offer the potential for the hAd5 vaccine to provide recipients with durable and long-term cell-mediated immunity with potent antibody stimulation against both the S and N proteins.
The company plans to begin a phase I trial of the novel vaccine candidate at Newport Beach-based Hoag Hospital in California this month.
In August this year, ImmunityBio said that its human hAd5 vaccine candidate, which is being developed for the prevention of Covid-19, has yielded positive preclinical results.
ImmunityBio chairman and CEO Dr Patrick Soon-Shiong said: “While there are a number of vaccine candidates in development, we believe most are limited by their sole focus on antibody responses to the monovalent spike protein, which may be insufficient to activate the full potential of the immune system to fight the coronavirus.
“By targeting the nucleocapsid protein on the interior of the virus particle as well as the spike protein on the virus’s surface, we believe this vaccine can stimulate both T-cell-mediated and antibody-mediated immunity to SARS-CoV-2.”
ImmunityBio’s Covid-19 vaccine programme includes IND clearance for phase I clinical study designed to assess oral Covid-19 vaccine.
Phase I, open-label and dose-ranging study will recruit healthy adults aged between 18 years and 55 years to evaluate the safety and reactogenicity of two-doses of the vaccine. It will also measure immunogenicity, duration of immune response and occurrence of symptomatic Covdi-19.
In August this year, ImmunityBio and its affiliate NantKwest agreed to equally share the costs of development, manufacturing, marketing and commercialisation of Covid-19 products, including the hAd5 vaccine candidate.
Both firms have agreed to split net profits in 60-40 ratio, and the larger share will be provided to the company that developed the product.