Tonix Pharmaceuticals Holding Corp. (Nasdaq: TNXP) has acquired worldwide rights to TNX-4800 (formerly mAb 2217LS), a long-acting human monoclonal antibody targeting outer surface protein A (OspA) of Borrelia burgdorferi, the bacterium that causes Lyme disease. TNX-4800 is being developed as a single subcutaneous dose administered in the Spring to protect against Lyme disease through the Fall tick season in the United States.

Lyme disease remains the most common vector-borne infection in the U.S., with approximately 70 million people living in endemic areas. No FDA-approved vaccines or prophylactic treatments are currently available.

Seth Lederman, MD, chief executive officer of Tonix, said: “Licensing TNX-4800 expands our infectious disease pipeline with a potentially differentiated, single-dose approach that can be given each Spring to provide protection within two days and protect through Fall, which is the entire tick season in the US.”

TNX-4800 was developed at UMass Chan Medical School, where Mark Klempner, MD, led the research team.

He said: “Preventing Lyme disease is an urgent public health priority, and more than thirty years of clinical experience confirm that monoclonal antibodies can be delivered safely and can be effective in preventing infections.”

Terence Flotte, MD, provost and dean at UMass Chan, added that the collaboration reflects the institution’s commitment to translational research addressing unmet medical needs.

The monoclonal antibody has an engineered extended half-life, allowing a single Spring dose to maintain protective titers throughout the season. By binding OspA, TNX-4800 blocks the maturation of Borrelia in infected deer ticks, preventing transmission to humans. Preclinical studies show it can block major Borrelia genospecies from ticks to animals, and it avoids the multidose schedules required for OspA vaccines previously in development or withdrawn.

Tonix plans to advance TNX-4800 through additional clinical trials with the goal of submitting a Biologics Licensing Application (BLA). A Phase 1 study demonstrated safety, tolerability, and a linear pharmacokinetic:pharmacodynamic:efficacy relationship. An adaptive Phase 2/3 study is being planned.