Tonix Licenses Global Rights To Sigma-1 Receptor Antagonist TNX-4900, A Non-Opioid Analgesic Candidate; For Neuropathic Pain

Tonix Pharmaceuticals Holding Corp. announced that it has secured exclusive worldwide licensing rights to TNX-4900, a highly selective small-molecule Sigma-1 receptor (S1R) antagonist with demonstrated analgesic activity in multiple preclinical models of neuropathic pain. Formerly known as PW507, the compound strengthens Tonix’s central nervous system pipeline and supports its focus on developing non-opioid pain therapies.

“Sigma-1 receptor antagonism has generated considerable scientific interest as a promising class of non-opioid, non-addictive analgesics,” said Seth Lederman, M.D., President and Chief Executive Officer of Tonix Pharmaceuticals. “With our extensive experience studying and developing an FDA approved non-opioid analgesic we are well-positioned to oversee this new development program. We believe TNX-4900 has the potential to be best-in-class.”

TNX-4900 originated from a structure-based drug design program at Rutgers University led by Dr. Youyi Peng and Dr. William Welsh. The compound exhibits high affinity for the human Sigma-1 receptor, strong selectivity over the Sigma-2 receptor, and favorable pharmacological properties, including effective blood–brain barrier penetration and oral bioavailability. These characteristics position TNX-4900 as a promising candidate for treating neuropathic pain conditions.

Dr. Youyi Peng, co-inventor of TNX-4900, formerly a Senior Bioinformatics Specialist at the Rutgers Cancer Institute of New Jersey and now a consultant to Tonix, added, “We used computer-aided and AI-driven approaches to design this new class of selective Sigma-1 receptor antagonists. TNX-4900 showed robust analgesic efficacy in multiple pain models and an encouraging safety profile, supporting its potential as a new non-opioid approach to treating neuropathic pain.”

In animal models of diabetic and chemotherapy-induced neuropathic pain, TNX-4900 produced significant and sustained reductions in pain-related behaviors following both acute and chronic administration. Importantly, the compound did not show evidence of tolerance development or motor impairment, supporting its potential suitability for long-term pain management. Tonix plans to advance TNX-4900 through expanded pharmacokinetic, formulation, and safety studies as part of its IND-enabling development pathway.

“Our foundational research into TNX-4900 represents an important step toward developing non-opioid solutions for chronic pain. We are pleased to see this innovation progress toward potential clinical application, which could address a critical need for safer pain management options,” said Dr. William Welsh, Distinguished Professor in the Department of Pharmacology at Rutgers Robert Wood Johnson Medical School (RWJMS).

Tonix is a fully integrated biotechnology company with both marketed products and a diversified pipeline of development. Its commercial portfolio includes TONMYA™, a first-in-class, non-opioid therapy approved by the FDA for the treatment of fibromyalgia, as well as two acute migraine treatments, Zembrace® SymTouch® and Tosymra®. The company’s broader pipeline spans CNS disorders, immunology, immuno-oncology, rare diseases, and infectious diseases.