LUNAR-COV19, a new COVID-19 vaccine candidate developed by Arcturus Therapeutics Holdings Inc. and Duke-NUS Medical School, could produce immunity at low doses, even only after a single administration.
The race to develop the world’s first safe and effective COVID-19 vaccine began nearly as soon as it was evident that a global pandemic was imminent.
International organisations, including the World Health Organisation (WHO) and the Coalition for Epidemic Preparedness Innovations (CEPI) have stepped up to facilitate global plans for vaccine distribution and to secure funding for COVID-19 vaccine research and manufacturing respectively. Several national governments, including those of Canada, China, France, the United Kingdom, and the United States have also dedicated resources towards vaccine research and manufacturing.
As of this time, there are more than 200 vaccine candidates in development and at least 25 in various stages of clinical trials, although no one vaccine has completed testing to prove its safety and efficacy yet.
San Diego-based company Arcturus Therapeutics Holdings Inc. and Singapore’s Duke-NUS Medical School (Duke-NUS) have worked together to develop a potential vaccine candidate, named LUNAR-COV19, which has been recently greenlighted for human clinical trials in Singapore.
The trial was approved by the Singapore Health Sciences Authority and will be administered by the SingHealth Investigational Medicine Unit. It will include up to 108 healthy adults in various age groups, including elders. Volunteers will be dosed with LUNAR-COV19 and dose levels will be evaluated, with follow-ups conducted to assess safety, tolerability and extent and duration of the humoral and cellular immune response.
Most vaccines used today to defend against other viruses consist of injecting weakened or inactivated forms of the virus into the body. The body produces neutralising antibodies and mounts a T cell response against the antigens injected, allowing the immune system to gain familiarity to the virus and quickly stamp out infection when the individual becomes exposed to the actual virus.
However, instead of sticking to the usual formula of a vaccine as described above, LUNAR-COV19 works through a different mechanism. It was developed using the new STARR™️ Technology platform developed by Arcturus Therapeutics and a unique platform for rapid screening for potential vaccine effectiveness and safety from Duke-NUS.
Using the STARR™️ Technology platform, self-replicating mRNA was combined with LUNAR®, a proprietary nanoparticle delivery system which is optimised for mRNA delivery. This efficient and self-replicating approach provides the advantage of the vaccine needing to be administered only once and requiring only very low doses in order to produce robust humoral and cellular immunity.
From preclinical studies of this new vaccine, it was seen that neutralising antibody levels continue to increase over a duration of 50 days, after administration of a single dose of LUNAR-COV19. This was found to be true for various LUNAR-COV19 dosage levels, from a low dose of 0.2 µg to a much higher dose of 10.0 µg. This effect was attributed to the self-replicating mRNA used in this approach.
Joseph Payne, President and CEO of Arcturus, is optimistic about the outcome of the clinical trials. According to him, “the approval of the Clinical Trial Application for LUNAR-COV19 is a critical milestone for Arcturus”, continuing that the company was “excited to advance this promising vaccine candidate into clinical trials”. He also expressed that the LUNAR-COV19 profile “may facilitate the mass vaccine campaigns necessary to target hundreds of millions of individuals globally.”
Representatives from Duke-NUS are also hopeful that LUNAR-COV19 could prove to be a viable vaccine candidate against COVID-19.
Professor Ooi Eng Eong, who is the Deputy Director of the Emerging Infectious Diseases Programme at Duke-NUS, said, “Preclinical studies on LUNAR-COV19 have shown very promising findings, including the possibility that a single dose of this vaccine may be sufficient to trigger robust and durable immune responses against SARS-CoV-2. We are very eager to start the first in-human clinical trial here in Singapore and advance LUNAR-COV19 on its journey to becoming a potential commercial vaccine.”
This sentiment is echoed by Processor Thomas M. Coffman, the Dean of Duke-NUS Medical School, who says that “there is a tremendous global imperative to develop effective preventive measures for COVID-19 infections. We are heartened by the rapid and promising progress in our vaccine collaboration with Arcturus as we move forward into clinical trials.”
Innovative solutions are required in the global fight against COVID-19, and international partnerships that generate new possibilities, such as the one between Arcturus Therapeutics and Duke-NUS, provide hope that a safe, viable and effective vaccine can be developed soon.