29 March 2022 - - The first healthy volunteer has been dosed in US-based immunotherapies developer HDT Bio Corp's US Phase 1 clinical trial of its next generation COVID-19 RNA vaccine, HDT-301, the company said.

The vaccine targets the Beta variant of SARS-CoV-2 and has a demonstrated ability to provide broad protection against multiple variants of the virus that causes COVID-19 and unique cellular immunity compared to existing mRNA vaccines.

Advancing HDT-Bio's novel vaccine into the clinic was also funded by a contract from the National Institute of Allergy and Infectious Diseases (NIAID) at the National Institutes of Health.

The trial will enroll a total of 60 healthy volunteers. Subjects who already have been vaccinated will receive either one or two injections, while those unvaccinated will receive two injections. Dose levels under investigation are 1, 5, and 25 μg (microgram).

When two injections are given, they will be separated by 56 days. In addition to establishing the safety of vaccine, other metrics will include magnitude and longevity of antibody and T-cell responses to the injections.

HDT Bio's clinical trials also will evaluate the safety and efficacy (including antibody and cellular responses) of its RNA vaccine at dose levels much lower than currently approved RNA vaccines.

HDT Bio's innovative vaccine uses a proprietary lipid nanoparticle carrier system for delivery of RNA. The vaccine is significantly different from commercially available RNA vaccines in two ways: First, its RNA payload is designed to amplify itself inside the body.

As a result, the vaccine effectively activates the immune system at a much lower dose--as little as 1/100th, than current vaccines, enhancing safety and reducing manufacturing costs.

Second, the RNA attaches to the outside of the nanoparticle system rather than becoming encapsulated within it providing for simplified manufacturing and increased stability, it can be stored at ordinary refrigerator temperatures.

To support HDT Bio's mission of reducing global heath inequities, the company has RNA vaccine collaborations underway with partners in China, Korea, and Brazil for its HDT-301 vaccine against COVID-19.

HDT Bio is a Seattle-based biopharmaceutical company focused on providing immunotherapies to people around the world, including those in historically underserved areas.

The company seeks to harness the body's immune system to deliver therapies that narrowly target the specific areas of the body where they are needed. HDT's work focuses on oncological and infectious disease applications.

HDT Bio's founders are in the development of immune stimulants, including both therapeutics and therapy-enhancing adjuvants.

One of the company's proprietary core technologies, RNA/LION, combines formulation and adjuvant ingredients to stabilize and deliver RNA to the immune system to stimulate responses for therapy or vaccination.