Tonix announces FDA alignment on Phase 2 Lyme disease prevention study for TNX-4800
Tonix Pharmaceuticals announced the receipt of official minutes from the Type C meeting with the U.S. Food and Drug Administration (FDA) to discuss the Company’s plans for an adaptive Phase 2 field study of TNX-4800 (human anti-outer-surface protein A [OspA] monoclonal antibody [mAb]) to prevent Lyme disease in adults in the U.S.
TNX-4800 is a potential seasonal immunopreventative alternative to vaccination and is Fc-modified for extended half-life and duration of protection.
Seth Lederman, M.D., Chief Executive Officer of Tonix Pharmaceuticals said, “The annual two dose regimen of TNX-4800, with a first dose in the early Spring and a second dose three months later, is expected to provide protection for at least six months, to cover the entire U.S. Lyme disease season. The protection is expected to begin within two days of the first dose. Pending FDA review and approval of the final protocol, we plan to test TNX-4800 as two subcutaneous (SC) injections three months apart. While this will be a Phase 2 study, it has the potential to demonstrate efficacy.”
“Our focus in 2026 has been on manufacturing investigational product for TNX-4800, which is on track for delivery to study sites in the first quarter of 2027,” said Zeil Rosenberg, M.D., Executive Vice President, Medical at Tonix. “The official FDA minutes indicate alignment on a randomized, placebo-controlled adaptive field study design enrolling approximately 3,300 adult participants over two seasons with a primary efficacy endpoint of Lyme disease prevention through six months after the first dose, and a key secondary efficacy endpoint of prevention through three months. The primary safety objective will be to evaluate the safety and tolerability of TNX-4800 over a 52-week period after dosing. We expect the majority of participants will be enrolled in the 2028 season. If the attack rate is lower than expected, enrollment could potentially extend into 2029.”
Participants in the planned adaptive Phase 2 field study will be randomized 1:1 to receive either TNX-4800 450 mg SC or a placebo, and another dose of TNX-4800 or placebo approximately three months later. The Company plans to enroll adult volunteers aged 18 and older who live in Lyme-endemic areas in the U.S. and engage in activities that increase their risk of deer tick bites.
