Fasedienol (PH94B) is a first-in-class, rapid-onset investigational pherine nasal spray with a novel proposed mechanism of action (MOA) that regulates the olfactory-amygdala neural circuits of fear and anxiety and attenuates the tone of the sympathetic autonomic nervous system, without systemic distribution, potentiation of GABA-A or direct activity on CNS neurons in the brain. Vistagen is developing fasedienol in a Phase 3 program for the treatment of social anxiety disorder (SAD). Designed for intranasal administration in low microgram doses, the proposed novel MOA of fasedienol is fundamentally differentiated from all FDA-approved approved anti-anxiety medications, including all three antidepressants approved by the U.S. Food and Drug Administration (FDA) for the treatment of SAD, as well as all benzodiazepines and beta blockers prescribed on an off-label basis.

The proposed MOA for PH94B does not involve systemic distribution, potentiation of GABA-A or direct activity on central nervous system (CNS) neurons in the brain. Rather, when administered intranasally, fasedienol activates receptors in the membrane of peripheral nasal chemosensory neurons connected to subsets of neurons in the olfactory bulbs that in turn connect to neurons in the limbic amygdala, a region in the brain that is involved in the pathophysiology of SAD.

The safety profile and potential for fasedienol to achieve overall reduction in symptoms of SAD and improvement in severity of the disorder, as measured by the Liebowitz Social Anxiety Scale (LSAS), have been demonstrated in a placebo-controlled Phase 2 study after two weeks of use, as well as in an open-label study over a period of one month and beyond.  These data suggest that studies involving multiple administrations of fasedienol over time, on an as-needed basis at moments when subjects experience real-life, socially stressful situations, most accurately demonstrate the safety and efficacy potential of fasedienol in patients with SAD and reflect the way we believe fasedienol would be used by SAD patients, if approved. Each SAD patient is unique, and we believe an optimal SAD treatment is one that is individualized and tailored-to-fit by patients, as-needed, to help them engage in the anxiety-provoking situations they encounter in their daily lives with less fear and anxiety.

The FDA has granted Fast Track designation for development of fasedienol for the treatment of anxiety in adults with SAD.