Tonix Pharmaceuticals Presented TNX-801 Mpox Vaccine Data at University of Alberta Symposium

Tonix Pharmaceuticals Holding Corp. recently presented new data demonstrating the efficacy of their TNX-801 vaccine, developed for protecting against mpox (formerly known as monkeypox), at a symposium hosted by the Department of Medical Microbiology & Immunology and the Li Ka Shing Institute of Virology. The event also honored the retirement of David Evans, Ph.D., from the University of Alberta. The TNX-801 vaccine platform, based on a synthetic horsepox virus, has shown promising results in preclinical studies and is being developed to provide a single-dose solution with long-lasting immunity.

TNX-801 is a live, attenuated virus vaccine designed for percutaneous administration. It is structurally similar to 19th-century vaccinia vaccines, which were used to eradicate smallpox. Unlike the 20th-century vaccinia vaccines that have higher virulence and toxicity, TNX-801 offers better tolerability and is less likely to spread in blood or tissues, even at high doses. The U.S. FDA recently approved ACAM2000, a 20th-century live-virus vaccinia vaccine, which has significant tolerability issues, including risks of myocarditis, encephalitis, and other severe complications. In contrast, TNX-801 aims to avoid these issues while providing effective protection.

The Jynneos vaccine, another FDA-approved mpox vaccine, requires a two-dose regimen and sterile injection. TNX-801, on the other hand, offers the advantage of single-dose administration without the need for sterile injection, potentially simplifying immunization logistics, especially in regions with limited healthcare infrastructure. The stability of live-virus vaccines like TNX-801, particularly in their lyophilized form, also eliminates the need for ultra-cold storage, which is a significant logistical challenge for mRNA vaccines.

Preclinical studies have shown that TNX-801 effectively protects animals from lethal challenges with clade I monkeypox virus, leading to a reduction in clinical disease, lesions, and viral shedding in the mouth and lungs. These results suggest that TNX-801 can induce mucosal immunity and block virus transmission, akin to the historical success of smallpox vaccines.

Tonix Pharmaceuticals is collaborating with Bilthoven Biologics, part of the Cyrus Poonawalla Group, to develop GMP manufacturing processes for TNX-801. This collaboration aims to ensure that the vaccine can be produced at scale and distributed efficiently. Tonix also sees potential in using the horsepox platform for developing other vaccines, including TNX-1800 for COVID-19, which has shown promising results in preclinical studies and has been selected for clinical testing by the NIH’s Project NextGen.

The recent global mpox outbreaks, caused by different clades of the monkeypox virus, highlight the urgent need for effective vaccines. The 2022 outbreak, caused by clade IIb, spread to over 90,000 people worldwide, demonstrating the pandemic potential of mpox. The current outbreak, caused by clade I, is associated with higher fatality rates and has spread to several countries, raising concerns among health authorities.

Tonix Pharmaceuticals is focused on addressing these public health challenges by developing TNX-801 as an mpox vaccine. Their efforts align with recommendations from the Bipartisan Commission on Biodefense and the U.S. National Academies of Science, which emphasize the importance of single-dose vaccines for effective outbreak control. The company is also exploring the potential of TNX-801 to serve as a platform for developing vaccines against other emerging infectious diseases.

In summary, TNX-801 represents a promising advancement in the fight against mpox, offering a single-dose, stable, and well-tolerated vaccine option. Tonix Pharmaceuticals continues to advance its development with the goal of providing a scalable and effective solution to prevent and control future mpox epidemics.