November 16, 2020 -- Tonix Pharmaceuticals has released preliminary results from nonhuman primate studies with TNX-1800, a live-attenuated COVID-19 vaccine candidate engineered to express the SARS-CoV-2 spike protein after vaccination.
The TNX-1800 vaccine candidate is administered percutaneously using a two-pronged, or "bifurcated," needle. TNX-1800 is based on a horsepox vector, which is a live replicating, attenuated virus that elicits a strong immune response.
The study of TNX-1800 in nonhuman primates compared a high and low dose to a placebo control group, each with four animals. The company found that at 14 days post-vaccination, the animals made anti-CoV-2 neutralizing antibodies and that the vaccine was well tolerated. There was no difference in the level of neutralizing antibodies between the low and high dose. All vaccinated animals manifested a "take" or cutaneous response, signaling that the horsepox vector elicited a strong T-cell immune response.
The company plans to evaluate the vaccine candidate in another study in animals challenged with SARS-CoV-2. Results from this experiment are expected in the first quarter of 2021. Tonix anticipates initiating a human phase I clinical trial in 2021 once they have a good manufacturing practice (GMP) quality product available.
Additionally, the study confirmed that TNX-1800 at the low dose of 1,000,000 plaque-forming units is an appropriate dose for a one-shot vaccine in humans, and indicated that 100 doses per vial is the target format for commercialization, which is suited to manufacturing and distribution at large scale. The company has partnered with Fujifilm Diosynth Biotechnologies for clinical manufacturing.
The research is part of an ongoing collaboration between the Southern Research Institute, the University of Alberta, and Tonix.