ImmunityBio has received authorisation from the US Food and Drug Administration (FDA) to initiate a Phase I trial of its novel Covid-19 vaccine candidate, hAd5-COVID-19.
The second-generation human adenovirus serotype 5 vaccine targets inner nucleocapsid (N) and outer spike (S) protein, engineered to activate T-cells and antibodies against SARS-CoV-2 respectively.
These dual SARS-CoV-2 constructs offer the possibility for the vaccine candidate to provide durable, long-term cell-mediated immunity with potent antibody stimulation to patients against both the S and N proteins.
The Phase I, open-label, dose-ranging trial will analyse the safety and reactogenicity of two-doses of the hAd5 vaccine as primary endpoints.
It will also evaluate immunogenicity, duration of immune response and occurrence of symptomatic Covid-19.
ImmunityBio plans to conduct the trial on healthy adults aged up to 55 years at Hoag Hospital in Newport Beach, California this month.
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.”
According to ImmunityBio, first-generation Covid-19 vaccines can deliver only the monovalent spike protein on the surface of the virus and can potentially provide antibody protection only.
While the second-generation vaccine that delivers both the S and N proteins can enable the recipients to develop immune memory to provide long-lasting immunity against the virus.
Preclinical development is progressing for oral, inhalational and intranasal administration of hAd5 vaccine to provide mucosal immunity and lasting humoral and cell-mediated immunity against the virus.