TNX-801 Mpox Vaccine Description
TNX-801 is a vaccine candidate that Tonix Pharmaceuticals Holding Corp. developed to protect humans against mpox and smallpox infection. TNX-801 was created as part of a research collaboration between Tonix and Professor David Evans, Ph.D., and Ryan Noyce, Ph.D., the Department of Cell Biology, University of Alberta. TNX-801 is a live virus vaccine based on synthesized horsepox, the sequence of the 1976 natural isolate Mongolian horsepox clone MNR-763. Molecular analysis of DNA sequences suggests that TNX-801 is closer than modern smallpox vaccines to the vaccine discovered and disseminated by Dr. Edward Jenner in 1798.
In July 2022, the Company Announced a collaboration with the Kenya Medical Research Institute (KEMRI) to seek regulatory approval for conducting a Phase 1 clinical study in Kenya to develop TNX-801. On November 9, 2022, the company gave a presentation on TNX-801 for Smallpox and Mpox. On December 1, 2022, the company gave a Presentation at the World Vaccine & Immunotherapy Congress.
On November 13, 2024, Tonix announced the publication of a paper entitled, “Recombinant Chimeric Horsepox Virus (TNX-801) is Attenuated Relative to Vaccinia Virus Strains in Both In Vitro and In Vivo Models,” in the peer-reviewed journal mSphere. The publication presents data demonstrating that TNX‐801 is less virulent than 20th-century vaccinia vaccines in immune-compromised mice.
Tonix is a clinical-stage biopharmaceutical company focused on discovering, licensing, acquiring, and developing therapeutics to treat and prevent human disease and alleviate suffering.
Recombinant Pox Virus Platform
Horsepox virus and vaccines based on its use as a vector are live replicating viruses that elicit strong immune responses. Live replicating orthopoxviruses, like vaccinia or horsepox, can be engineered to express foreign genes and have been exploited as platforms for vaccine development because they possess (1) large packaging capacity for exogenous DNA inserts, (2) precise virus-specific control of exogenous gene insert an expression, (3) lack of persistence or genomic integration in the host, (4) strong immunogenicity as a vaccine, (5) ability to rapidly generate vector/insert constructs, (6) manufacturable at scale, and (7) ability to provide direct antigen presentation. Relative to vaccinia, horsepox has substantially decreased virulence in mice2. Horsepox-based vaccines are designed to be single-dose, vial-sparing vaccines manufactured using conventional cell culture systems, with the potential for mass-scale production and packaging in multi-dose vials.
TNX-801 News
November 13, 2024 - “Addressing the new Clade Ib mpox outbreak and the ongoing spread of Clade IIb mpox may require a single dose mpox vaccine that provides durable protection,” said Seth Lederman, M.D., Chief Executive Officer of Tonix Pharmaceuticals.
December 1, 2022 - Tonix Pharmaceuticals Holding Corp. announced that Seth Lederman, M.D., CEO of Tonix Pharmaceuticals, presented data from the Company’s TNX-801 smallpox and monkeypox vaccine development program in an oral presentation. “TNX-801 is a live virus vaccine that we believe is closer to the smallpox vaccines used in the U.S. and Europe before 1900 than the modern vaccinia smallpox vaccines. TNX-801 has reduced virulence in animals, and we believe it has the potential for widespread use to protect against monkeypox,” said Seth Lederman, M.D., President and CEO.
TNX-801 Clinical Trials
Tonix Pharmaceuticals Holding Corp. (Nasdaq: TNXP) announced a collaboration with the Kenya Medical Research Institute (KEMRI) to plan, seek regulatory approval, and conduct a Phase 1 clinical study in Kenya to develop TNX-801 as a vaccine to protect against monkeypox and smallpox. The study is expected to start in the first half of 2023.
“KEMRI is excited to plan this clinical trial with Tonix and ultimately to lead the trial,” said Professor Samuel Kariuki, Director General and CEO of KEMRI. “Monkeypox has spread in Central and West Africa, and there’s a concern that we could begin seeing cases in Eastern and Central Africa or from foreign travelers. Recently, monkeypox has been reported in over 30 countries outside of Africa that were not endemic to the monkeypox virus. We are grateful that Tonix is committed to sponsoring clinical studies and making TNX-801 available for this important problem.”
