SAN DIEGO—Arcturus Therapeutics Holdings Inc., a leading clinical-stage messenger RNA medicines company focused on the development of infectious disease vaccines and significant opportunities within liver and respiratory rare diseases, says its vaccine against SARS-CoV-2 infection (and thus development of COVID-19) is showing great promise in preclinical studies.
Specifically, the company announced Sept. 4 that a manuscript on that research is now available on an online preprint server at Bioarchive and is concurrently undergoing scientific peer review. The manuscript provides an in-depth assessment of humoral- and cell-mediated immune activation following a single shot vaccination in mice and shows that LUNAR-COV19 (also designated as ARCT-021) produced robust antibody responses, with neutralizing antibody titers increasing up to day 60. In addition, single doses of LUNAR-COV19 at both the 2 μg and 10 μg levels completely protected human ACE2 transgenic mice from both mortality and even measurable infection following wild-type SARS-CoV-2 challenge.
The company believes that the findings from this study, which was conducted in collaboration with Duke-NUS Medical School, collectively suggest the potential of LUNAR-COV19 as a single-dose vaccine. The company is currently evaluating LUNAR-COV19 in a Phase 1/2 clinical study.
The publication: “A Single Prime Self-Transcribing and Replicating RNA Based SARS-CoV-2 Vaccination Produces Protective Adaptive Immunity” is available on the Bioarchive website at https://www.biorxiv.org/content/10.1101/2020.09.03.280446v1
“The data we have in preprint at Bioarchive continues to provide strong support for the potent immunogenicity of LUNAR-COV19. Results demonstrate that a single vaccination in mice led to robust antibody responses ... Furthermore, activation of cell mediated immunity produced a strong viral antigen specific CD8+ T lymphocyte response and a desirable Th1 dominant immune response,” said Prof. Ooi Eng Eong, deputy director of the Emerging Infectious Diseases Programme at Duke-NUS Medical School and a member of Arcturus’ Vaccine Platform Scientific Advisory Board. “Importantly, a single LUNAR-COV19 vaccination at very low microgram doses resulted in complete protection from infection and death from SARS-CoV-2 in a transgenic human ACE2 mouse challenge model, with no detectable virus present in LUNAR-COV19 vaccinated mice.”
“Our findings highlight the potential of LUNAR-COV19 to be a highly potent, low dose, single shot vaccine. These favorable attributes may provide a substantial benefit compared to the multiple vaccine dosing regimens that are more commonly being developed. We believe that this advantageous profile could greatly facilitate the mass vaccination campaigns necessary to control the global COVID-19 pandemic,” said Dr. Pad Chivukula, chief scientific officer and chief operating officer of Arcturus.