Tonix Pharmaceuticals Publishes TNX-1500 Clinical Study Results

Tonix Pharmaceuticals announced the publication of a paper, "First-in-Human, Phase 1, Randomized, Double-Blind, Placebo-Controlled Study of TNX-1500, an Fc-Modified anti-CD154 Monoclonal Antibody, Evaluating the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Single-Ascending Doses in Healthy Adults," in the peer-reviewed Journal of Clinical Immunology. TNX-1500 is an investigational, third-generation Fc-modified IgG4 anti-CD40L monoclonal antibody in development for the prevention of organ transplant rejection and the treatment of autoimmune diseases. The publication reports findings from a single-center, first-in-human, Phase 1, randomized, double-blind, placebo-controlled, single-ascending dose escalation study in 26 healthy adult volunteers. Participants were enrolled across three ascending dose cohorts or placebo and received a single intravenous infusion of TNX-1500 or placebo, followed by intramuscular injections of KLH on days 2 and 29 to assess the TDAR, and monitored over a 120-day follow-up period. TNX-1500 blocked the primary T cell-dependent antibody response to KLH at all doses, blocked the secondary response at the 10 and 30 mg/kg doses, and reduced peak secondary response to KLH by ~70% relative to placebo at the 3 mg/kg dose. TNX-1500 was generally well tolerated, with no serious adverse events, and no discontinuations due to adverse events. The only treatment-emergent adverse event deemed possibly related to study drug was aphthous ulcer, which occurred in 1 participant in each of the three TNX-1500 groups; all TEAEs were rated as mild and resolved in 2-10 days. No TEAEs were determined to be related to KLH administration. There were no administration or injection site reactions. Pharmacokinetic analyses suggested approximately dose-proportional exposure across the 3 to 30 mg/kg range, with mean terminal elimination half-lives of 37.8 and 33.8 days at the 10 and 30 mg/kg dose levels, respectively. TNX-1500 at 10 and 30 mg/kg blocked the primary and secondary anti-KLH TDAR through day 120, and at 3 mg/kg reduced the peak secondary response by approximately 70% relative to placebo. Across all dose cohorts, TNX-1500 was associated with a rapid and sustained reduction in soluble CD40L over the 120-day study period.