ImmunityBio has shared preclinical data on its oral COVID-19 vaccine. The pairing of a subcutaneous prime shot with two oral boosters protected nonhuman primates against the coronavirus, setting Patrick Soon-Shiong’s ImmunityBio up to expand its clinical development program.
Working with the Biomedical Advanced Research and Development Authority, ImmunityBio tested two regimens of its viral vector vaccine in 10 nonhuman primates. Five subjects got subcutaneous doses on days 0 and 14, followed by an oral tablet on Day 28. The other five subjects began with a subcutaneous dose but switched to the oral formulation for the two boosters.
Levels of anti-spike antibodies rose in almost all subjects, particularly after the administration of the first or second booster shot. One of the primates in the group that took two oral boosters had little to no antibody response, reaching Day 42 with levels comparable to those of the control subjects.
ImmunityBio assessed the protection provided by the immune response by infecting the primates with SARS-CoV-2 on Day 56 of the study. Viral load and replicating virus in the nasal passages and lungs fell faster in the two vaccine cohorts than in the control group. The drops were similarly steep in the two vaccine cohorts.
Buoyed by the data, ImmunityBio plans to move the oral vaccine into phase 1. The early-phase trial will assess the oral formulation as a prime and a boost, as well as a boost to a subcutaneous shot in a mixed regimen more like that tested in the nonhuman primates.
ImmunityBio began a phase 1 trial of an injectable formulation of its vaccine in October. In disclosing the nonhuman primate study, which was released as a preprint, ImmunityBio said it has completed testing the subcutaneous vaccine in 20 subjects in phase 1 and is recruiting a phase 2/3. The phase 1 is currently the only ImmunityBio-sponsored COVID-19 vaccine study on ClinicalTrials.gov.
With the leading vaccines now coming to market, ImmunityBio needs to differentiate its candidates to compensate for the big head start it has ceded to other companies. The oral formulation, which ImmunityBio says is stable at room temperature, could be such a point of differentiation.
An all-oral vaccine regimen that can be distributed and stored at ambient temperatures could lessen or eliminate some of the challenges of getting vaccines to people. ImmunityBio also sees its use of both outer spike and inner nucleocapsid antigens as a differentiator. The choice is intended to ensure the activation of virus-specific T cells and the generation of neutralizing antibodies.
ImmunityBio is one of several companies working on ways to vaccinate people against COVID-19 without injections. Vaxart already has an oral candidate in the clinic and is set to deliver data early next year. Altimmune expects to have phase 1 data on its single-dose intranasal vaccine in the first quarter of 2021.