ImmunityBio, a privately-held immunotherapy company, and NantKwest, Inc. a clinical-stage, natural killer cell-based therapeutics company, announced they have administered their second-generation bivalent, human adenovirus (hAd5) COVID-19 vaccine candidate in a Phase 1 trial with no SAEs reported in the low dose cohort, safety assessments are ongoing for the high dose cohort. The trial, being conducted at Hoag Hospital in Newport Beach, California, has enrolled 20 volunteers across two dose levels and subject screening for the Phase I expansion cohort is ongoing.
Developed by ImmunityBio and manufactured by NantKwest, this second generation hAd5-vector vaccine is unique in targeting both spike (S) and nucleocapsid (N) SARS-CoV-2 proteins. The vaccine is designed to generate both antibodies and CD4+ and CD8+ T cell responses, all of which we believe are necessary for generating long-term immune memory. A recent study of responses of T cells from convalescent plasma collected from previously-infected SARS-CoV-2 patients demonstrated that the hAd5 vaccine could stimulate recall of SARS-CoV-2 specific CD4+ and CD8+ memory T cells from these patients to the S and N proteins delivered by the hAd5-COVID-19 vaccine. This finding of immune recall suggests that the hAd5 COVID-19 vaccine could potentially elicit cell-mediated immune responses in convalescent, previously infected patients to stimulate and boost memory T cells specific to SARS-CoV-2.
“We are grateful to the many volunteers who are participating in this important Phase 1 study of our COVID-19 vaccine candidate,” said Patrick Soon-Shiong, M.D., Chairman and CEO of ImmunityBio. “Given the urgent need for long-term protection from SARS-CoV-2 viruses and the alarming increase of infection in our country, we’re heartened by what we’ve observed so far and hope to be able to move quickly to a Phase 2/3 randomized, double-blind control trial, involving a larger group of volunteers including persons previously infected with SARS-CoV-2.”