Monday, March 30: Phase 1 data on TNX-4800 (long-acting anti-Borrelia OspA human monoclonal antibody) for the seasonal prevention of Lyme disease
Wednesday, April 1: Animal and in vitro studies on TNX-801 (horsepox, live virus vaccine) for the prevention of smallpox and mpox
Wednesday, April 1: Horsepox as a modular antigen-delivery system for broad and sustained immunity in novel vaccines to protect against other pathogens
BERKELEY HEIGHTS, N.J., March 23, 2026 (GLOBE NEWSWIRE) -- Tonix Pharmaceuticals Holding Corp. (Nasdaq: TNXP) (“Tonix” or the “Company”), a fully integrated, commercial biotechnology company, today announced an oral presentation of Phase 1 data on TNX-4800 (formerly known as mAb 2217LS)1,2, a long-acting human monoclonal antibody (mAb) that targets the outer surface protein A (OspA) of Borrelia burgdorferi, the causative agent of Lyme disease in humans in the U.S., at the World Vaccine Congress Washington 2026 held in Washington, D.C., March 30-April 2, 2026.
The Company’s Farooq Nasar, PhD, Director, Virology will present data on TNX-801, the Company's attenuated, live orthopoxvirus (horsepox) vaccine candidate with the potential capability to protect against smallpox and mpox. Finally, Christopher Cooper, PhD, Director, Immunology at Tonix will serve as moderator on a panel discussing modular antigen-delivery systems in novel pox-based vaccines.
TNX-4800 Presentation Details
Title: A Long-Acting Monoclonal Antibody for Seasonal Prevention of Lyme DiseaseLocation: Room 202BDate and Time: March 30, 2026, 10:10 a.m. ETSession Category: Measuring Breadth & Emerging Targets Presenters: Mark S. Klempner, MD, Professor of Medicine at UMass Chan Medical School, inventor of TNX-4800, and Principal Investigator of the study
Other Session Details
Title: A Live Attenuated, Minimally Replicative MPOX VaccineLocation: Room 202A, Level 2Date and Time: April 1, 2026, 10:10 am ETSession Category: Emerging & Re-Emerging DiseasesPresenter: Farooq Nasar, PhD, Director, Virology, Research and Development Center (RDC), Tonix Pharmaceuticals
Title: Poxvirus as a Modular Antigen-Delivery System for Broad and Sustained ImmunityLocation: Room 20A, Level 2Date and Time: April 1, 2026, 3:25 p.m. ETSession Category: Emerging & Re-Emerging DiseasesModerator: Christopher Cooper, PhD, Director, Immunology, RDC, Tonix Pharmaceuticals
About TNX-4800TNX-4800 (formerly known as mAb 2217LS) is a human monoclonal antibody with an engineered extended half-life that targets the outer-surface protein A (OspA) on Lyme-causing Borrelia bacteria. When TNX-4800-containing blood is ingested by the tick, TNX-4800 kills and blocks the maturation of Borrelia burgdorferi in the mid-gut of infected deer ticks. The Company in-licensed TNX-4800 from UMass Chan Medical School in 2025. Published work in animals showed that TNX-4800 was 95% effective in preventing infection after a six-day challenge with ticks infected with Borrelia burgdorferi.1 TNX-4800 was derived from mAb 2217 by amino acid substitutions in its crystallizable fragment (Fc) domain which serve to prolong the serum half-life. A single administration in the Spring is designed to potentially provide immunity within two days and maintain protective antibody titers for the entire tick season, providing pre-exposure prophylaxis against Lyme disease without relying on the recipient’s immune system to generate antibodies. By delivering a well-characterized antibody directly, TNX-4800 has been shown to block transmission of Borrelia burgdorferi from ticks to animals. TNX-4800 also sidesteps the multidose schedules required for OspA vaccines in development3 and the FDA-approved vaccine that was withdrawn from the market.4 The Company expects to have GMP investigational product available for clinical testing in early 2027. Pending FDA clearances, a field study is expected to initiate enrollment in the first half of 2027, and a controlled human infection model (CHIM) study in 2028.
About the TNX-4800 Phase 1 StudyTNX-4800 was studied in a randomized, double-blind, sequential dose-escalation study (NCT04863287) that evaluated safety, tolerability, pharmacokinetics (PK), and immunogenicity of TNX-4800 in healthy adults. 44 subjects were randomized, and 41 completed the study. Subjects received a single subcutaneous (SC) administration of placebo or TNX-4800 at 0.5, 1.5, 5, or 10 mg/kg. Safety was assessed via clinical and lab evaluations. Drug exposure increased by approximately 25 times for a 20 times increase in dose. Serum TNX-4800 was measurable at the earliest sampling time of 24 hours, indicating rapid systemic absorption. TNX-4800 concentrations remained quantifiable for >200 days in 80% of volunteers at the lowest dose and for up to 350 days in the majority of volunteers at higher doses (i.e., ≥ 1.5 mg/kg). Mean half-life ranged from 62-69 days across groups. Serum concentrations remained quantifiable for up to 12 months in most subjects. Mean exposure for the 10 mg/kg cohort was less than 20% of the highest exposures in a rat toxicology study. Anti-drug antibodies (ADA) were detected in