9 November 2022 - - Australian biotechnology company Vaxxas has initiated a Phase I clinical trial with the first needle-free COVID-19 vaccine candidate delivered using Vaxxas' proprietary high-density microarray patch (HD-MAP) technology, the company said.

The COVID-19 vaccine patch is based upon HD-MAP delivery of HexaPro, a second-generation version of the spike protein used in all major US approved COVID-19 vaccines, which was modified to be more stable and immunogenic than its predecessor, giving potential coverage of all major SARS-CoV-2 variants.

Results from preclinical animal studies completed in July of this year and detailed below illustrate the potential efficacy of the COVID-19 vaccine patch against all currently known variants of concern.

The Phase I clinical trial will assess the safety and tolerability, and immunogenicity of the COVID-19 vaccine candidate in 44 healthy adults, aged 18 50 years inclusive, who have had three doses of an authorized COVID-19 vaccine, with the last dose at least four months prior to participating in the study.

In addition to demonstrating the safety of the vaccine candidate, the trial is designed to gather signals related to antibody and T-cell responses to dosing with the patch-delivered vaccine candidate.

HexaPro, a highly stabilized protein that is designed to mimic the structure of the spike protein on the surface of the coronavirus to train the human immune system to recognize and fight SARS-CoV-2 infection, is the most advanced spike protein from UTA's world-renowned vaccine development team.

Preclinical research published in Science Advances and Vaccine and undertaken with The University of Queensland and collaborators demonstrated that HexaPro delivered using Vaxxas' HD-MAP resulted in enhanced virus neutralizing antibody and T-cell responses against all known variants of concern, including alpha, beta, gamma, delta, and omicron, when compared to needle and syringe vaccination with HexaPro.

The University of Texas at Austin's Professor Jason McLellan and his collaborators at the NIH are the designers of an early version of the SARS-CoV-2 spike protein that was genetically altered by swapping in two amino acids called prolines, used to stabilize the spike protein and allow the immune system to better fight off infection.

The earlier spike protein is used in leading existing COVID-19 vaccines distributed in the United States and others approved under emergency use authorization in multiple countries.

In 2020, McLellan and his lab teamed up with the labs of two other UT Austin faculty members--Ilya Finkelstein, an associate professor in the Department of Molecular Biosciences, and Jennifer Maynard, a professor in the Cockrell School of Engineering--in designing a new spike protein, this time stabilized with six genetic alterations and so named HexaPro.

In July of 2020, the team published findings in Science that HexaPro induces immunologic expression of up to 10 times as much protein as the spike protein found in the current COVID-19 vaccines, making it a more powerful vaccine antigen for use in second generation COVID-19 vaccines.

The company's proprietary HD-MAP technology platform utilizes an ultra-high-density array of projections invisible to the naked human eye applied to the skin as a patch sitting inside a small applicator device.

When applied to the skin, the patch delivers vaccine to the abundant immune cells immediately below the skin surface.

This approach can enhance the efficiency and effectiveness of resulting immune responses of vaccines.

Vaxxas uses proprietary dry-coating technology to apply an active and stable vaccine onto the projections which offers the potential to eliminate the need for vaccine refrigeration during storage and transportation reducing the resource and logistics burden of maintaining the refrigerated "cold chain."

Ease of use of the HD-MAP could enable simplified administration, potentially encompassing self-administration.

To create the COVID-19 vaccine candidate, Vaxxas' HD-MAP is coated with HexaPro vaccine and integrated into a single-use applicator, ready-for-vaccination.

All vaccine candidates applied to the Vaxxas HD-MAP are designed to be effective and easy-to-use, while meeting industrial-scale manufacturing and commercial logistics requirements.

In extensive laboratory testing published in PLoS Med, Vaxxas' HD-MAP delivered vaccines have been shown to be stable and remain active when stored and transported at room temperature and demonstrate greater safety and protection, along with a potential for a lower dose, when compared to needle and syringe delivery of vaccine antigens, including the HexaPro SARS-CoV-2 spike protein.

Vaxxas has completed three human clinical studies with its HD-MAP involving more than 300 participants, demonstrating safety, and enhanced immune response of vaccine administration by HD-MAP.

Vaxxas is a privately held biotechnology company focused on enhancing the performance of existing and next-generation vaccines with its proprietary high-density microarray patch (HD-MAP). Vaxxas is targeting initial applications in infectious disease and oncology.

In addition to this Phase I clinical study of the COVID-19 vaccine candidate patch, Vaxxas is performing demonstration work in preparation for clinical evaluation under contract with the United States Biomedical Advanced Research and Development Authority (BARDA) on pandemic vaccination solutions.

Vaxxas' core technology was initially developed at The University of Queensland, and the company was established as a start-up in 2011 by UQ's commercialisation company UniQuest.

The company was founded with the completion of an initial equity financing led by OneVentures Innovation Fund I with co-investors Brandon Capital Partners, Brandon BioCatalyst, and US-based HealthCare Ventures, followed by a further financing led by OneVentures.

OneVentures Innovation Fund I and Brandon BioCatalyst are supported by the Australian government's Innovation Investment Fund program.

The IIF is an Australian government venture capital initiative that provides investment capital and managerial expertise through licensed venture capital fund managers to investee companies.

Vaxxas' HD-MAP delivered vaccines are under investigation and available only for investigational uses. They are not available anywhere in the world for sale or purchase.