Vistagen Receives Notice from European Patent Office of Intention to Grant Patent for AV-101 to Treat Neuropathic Pain

Vistagen (Nasdaq: VTGN), a late clinical-stage biopharmaceutical company aiming to transform the treatment landscape for individuals living with anxiety, depression, and other central nervous system (CNS) disorders, today announced that the European Patent Office (EPO) issued a Notice of Intention to Grant a patent related to the use of AV-101 for the treatment of neuropathic pain. AV-101 is the Company’s investigational oral prodrug of 7-chloro-kynurenic acid (7-Cl-KYNA), a potent and selective full antagonist (i.e., inhibitor) of the glycine coagonist site of the N-methyl-D-aspartate receptor (NMDAR). The patent, once granted, will not expire until at least 2034 and will become part of Vistagen’s global patent portfolio on therapeutic uses and manufacturing techniques for AV-101.

AV-101 Preclinical Data in Pain Models

Preclinical data previously published in the peer-reviewed journal, The Journal of Pain,¹ demonstrate robust antinociceptive effects, similar to gabapentin, but with a better side effect profile in several preclinical models of hyperalgesia and allodynia. In the study, AV-101 prodrug was systematically administered in four rat models of pain to examine its analgesic and behavioral profile. Dose-dependent anti-hyperalgesia effects were shown in the four models of pain. Compared to the control drugs tested (gabapentin and MK-801), AV-101 has similar robust anti-nociceptive effects but, contrary to the control drugs tested, AV-101 had no discernable negative side effects. The preclinical study was conducted by Tony L. Yaksh, PhD, Professor of Anesthesiology and Pharmacology at the University of California, San Diego.

Further preclinical research conducted by Dr. Yaksh comparing AV-101 to pregabalin in the Chung ligation model of pain, an accepted gold standard preclinical model for chronic neuropathic pain caused by nerve damage, demonstrated that AV-101 had a significant dose response with similar efficacy in this rat model of a mononeuropathy as compared to pregabalin, which was used as an active comparator. The statistically significant positive preclinical results suggest AV-101’s potential to treat multiple hyperpathic pain states.²

AV-101 Phase 1 Clinical Data

Additionally, clinical data from both the single and multi-dose Phase 1 studies previously published in the peer-reviewed publication, Scandinavian Journal of Pain,³ indicated that oral AV-101 was well-tolerated, with no meaningful difference in adverse events at any dose between AV-101 and placebo. Although the AV-101 study was not designed to achieve statistical significance in reducing pain in healthy volunteers, there were consistent reductions for allodynia pain and mechanical and heat hyperalgesia. The study was conducted by Mark S. Wallace, MD, Professor of Anesthesiology and Pain Management Specialist at the University of California, San Diego.⁴