ImmunityBio Reports Interim Phase 1 Safety Data Of hAd5 T-Cell COVID-19 Vaccine Candidate In Oral, Sublingual Formulations: 'Safety assessment completed for first 12 participants, no serious adverse events reported; trials expected to be fully enrolled Q2

Benzinga · 03/15/2021 13:02

ImmunityBio, Inc. ((IBRX), a clinical-stage immunotherapy company, today announced it has met the safety requirements for the first 12 participants in its Phase Ib human adenovirus (hAd5)-based T-cell COVID-19 vaccine trials in sublingual and oral formulations. The independent Safety Review Committee recommended the study continue with no modifications to the trial design. The trials, which will involve 80 participants, are expected to be fully enrolled in Q2.

The two U.S. Phase Ib trials are studying a combination of subcutaneous/ sublingual (under the tongue) (NCT04591717) and subcutaneous/oral (NCT04732468) formulations of ImmunityBio’s hAd5 T-cell COVID-19 vaccine candidate. Six participants have been dosed in each trial to date and the trial is anticipated to be fully enrolled in Q2 (prime plus boost). Based on the findings of these trials, the optimal combination of administration route and dose will be determined and entered into the Phase II/III design.

“We have not seen any serious adverse events in the participants who have received the hAd5 vaccine subcutaneously,” said Philip Robinson, M.D., the trial Principal Investigator and Medical Director of Infection Protection at Hoag Memorial Hospital Presbyterian in Newport Beach, California where the vaccine trials are being conducted. “Unlike most of the COVID-19 vaccines currently available, ImmunityBio’s hAd5 generates T-cell immunity, which is important for long duration immunity. Based on the results of subcutaneous/oral regimen in the nonhuman primate study where the vaccine provided complete protection against the virus challenge, we are excited to explore with ImmunityBio the potential for the vaccine to provide a T-cell boost to currently available vaccines. I am particularly encouraged by the immune response to the nucleocapsid protein, which may mean this vaccine will remain effective against the many emerging spike protein variants.”

Additional Data from BARDA-Funded Non-Human Primate Study
At the recent 2021 Conference on Retroviruses and Opportunistic Infections (CROI), ImmunityBio scientists presented pre-clinical data from SARS-CoV-2 challenge study involving subcutaneous and oral immunization that shows hAd5-COVID-19 T-cell vaccine candidate is completely protective in non-human primates against high SARS-CoV-2 titer exposures. This data is critically relevant to NCT0473468 mentioned above which is testing various combinations of subcutaneous and oral capsule administration in a Phase I clinical trial.

The vaccine-focused presentation, titled “Dual-Antigen Covid-19 Vaccination with Oral Boost Protects NHP from Viral Challenge”, detailed the results of a BARDA-funded COVID-19 challenge study in rhesus macaques assessing the antibody- and T cell-mediated immune responses to vaccination and protection against live SARS-CoV-2 challenge with ImmunityBio’s human adenovirus (hAd5)-based T-cell COVID-19 vaccine candidate in serial subcutaneous and oral administrations.

Key presentation results include:

  • ImmunityBio’s vaccine candidate is a bivalent construct incorporating genes encoding a modified SARS-CoV-2 spike fusion protein and the SARS-CoV-2 nucleocapsid fusion protein. The second-generation, non-replicating hAd5 vector platform is being used has been manufactured in both subcutaneous and oral formulations.
  • Ten rhesus macaques received either a subcutaneous (SC) prime dose followed by two oral boost doses (n=5) or two SC primes followed by one oral dose (n=5), with a two-subject placebo group.
  • Neutralizing anti-spike antibodies and activated T cells activated against both the spike and nucleocapsid proteins were detected.
  • Following a high-titer (106 TCID50) viral challenge, viral replication was assessed in nasal and respiratory passages.
  • In all vaccinated rhesus macaques, investigators observed inhibition of viral replication in both lung and nasal passages within 24 hours of viral challenge, with viral load undetectable within 7 days compared to placebo controls. Enhanced antibody neutralization was noted in the days following the challenge, suggesting that memory B cells had been activated at the time of dosing.
  • ImmunityBio’s COVID-19 vaccine candidate protects non-human primates from high-titer SARS-CoV-2 challenge when administered as subcutaneous prime with oral boost administration.
  • The efficacy of the oral capsule formulation of the vaccine candidate is especially encouraging, as its stability at room temperate would facilitate cold chain-free vaccine distribution around the world.