Vistagen announced that the last patient has completed the study protocol in its Phase 2 clinical trial of PH94B for the treatment of adults experiencing adjustment disorder with anxiety (AjDA). The exploratory Phase 2 clinical trial is a U.S. multi-center, randomized, double-blind, placebo-controlled study intended to evaluate efficacy, safety and tolerability of PH94B administered four times per day over four weeks for the treatment adjustment disorder with anxiety symptoms in adults. The primary endpoint is the change from baseline in anxiety level as measured by the Hamilton Anxiety Rating Scale (HAM-A) at the end of Week 4 of treatment with PH94B or placebo.

Dr. Michael Liebowitz, a former Columbia University psychiatrist, founder of the Anxiety Disorders Clinic at the New York State Psychiatric Institute, and currently director of the Medical Research Network in New York City, is serving as Principal Investigator of the trial. Topline results are anticipated at the end of first quarter of 2023. Vistagen's 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 PH94B in a Phase 3 program for the treatment of social anxiety disorder and in an exploratory Phase 2 development program for the treatment of adjustment disorder with anxiety. Designed for intranasal administration in low microgram doses, the proposed novel MOA of PH94B is fundamentally differentiated from all currently approved anti-anxiety medications, including all antidepressants and benzodiazepines. Adjustment disorder (AjD) refers to a maladaptive emotional or behavioral response to an identifiable stressor.

AjD occurs within three months of exposure to the stressor as evidenced by marked distress that is out of proportion to the socially or culturally expected reactions to the stressor, or that represents significant impairment in social, occupational or other important areas of daily functioning. A Mental Health Surveillance Study estimated prevalence of adjustment disorder at 7% in the U.S. adult population, or about 18 million adults in the U.S, in 2022. Current pharmacological treatments for AjD vary widely.

Current treatments include antidepressants, benzodiazepines and buspirone, among others.