Benzinga | Oct 5, 2021 08:03AM EDT

VistaGen Therapeutics Reports New Preclinical Mechanism Of Action Data; Co Says Data Supports PH94B's Potential Anti-Anxiety Activity Via Peripheral Nasal Neurons Without Entry Into Brain

VistaGen Therapeutics (NASDAQ:VTGN), a biopharmaceutical company developing a new generation of medicines with potential to go beyond the current standard of care for anxiety, depression and other central nervous system (CNS) disorders, today announced new mechanism of action data from a preclinical tissue distribution study in laboratory rats demonstrating that a single intranasal administration of radiolabeled carbon-14 PH94B ([14C]PH94B) was largely confined to the nasal passages and minimal or undetectable in most other tissues, including the CNS. No appreciable activity was observed in the brain.



These data further support the proposed mechanism of action of PH94B involving binding to receptors of peripheral neurons in the nasal passages, not to neuronal receptors in the CNS, and thereby limiting transport of molecules to the circulatory system and minimizing potential systemic exposure.

"We are very excited about these new study results, which further highlight how the mechanism of action of PH94B is fundamentally differentiated from all current anti-anxiety therapies," stated Shawn K. Singh, Chief Executive Officer of VistaGen. "When combined with previously announced preclinical electrophysiology data demonstrating that the mechanism of action of PH94B does not involve direct activation of GABA-A receptors, which is in distinct contrast to the mechanism of action of benzodiazepines, we see a growing body of evidence suggesting that PH94B has potential to achieve anti-anxiety effects without requiring systemic uptake or causing benzodiazepine-like side effects and safety concerns. At a time when the current drug treatment paradigm for Social Anxiety Disorder, or SAD, is falling far short of delivering necessary relief without worrisome potential consequences, an innovative treatment alternative is imperative. If successfully developed in our ongoing PALISADE Phase 3 Program, PH94B has the potential to fill that void as the first fast-acting, on demand acute treatment of anxiety for more than 23 million Americans who suffer from SAD."

"In this study, the absence of radiolabeled PH94B in the rodent brain is an encouraging sign that PH94B may have limited circulatory systemic exposure when administered intranasally," stated Mark Smith, MD, PhD, Chief Medical Officer of VistaGen. "Furthermore, the tissue distribution of radiolabeled carbon-14 PH94B was minimal in the tested lab animals, with the highest concentration primarily in the nasal turbnates. These findings strongly support a local disposition of PH94B in the olfactory receptor neurons and an absence of binding of PH94B in the central nervous system. We believe that this is another positive indication supporting the clinical development of PH94B."