VistaGen Therapeutics has unveiled top-line results from its PALISADE-1 Phase 3 clinical trial of PH94B, its investigational treatment for social anxiety disorder in adults.

PH94B is an odourless, tasteless, rapid-onset pherine nasal spray, designed to regulate the olfactory-amygdala neural circuits of fear and anxiety.

The drug did not achieve its primary endpoint of change from baseline using the Subjective Units of Distress Scale (SUDS) compared to placebo.

However, PH94B showed a favourable tolerability profile in PALISADE-1, which is consistent with previous results from all other clinical trials.

The experimental drug did not result in any severe or serious adverse events in prior clinical trials or in PALISADE-1, said the company.

VistaGen chief executive officer Shawn Singh said: “While the results of PALISADE-1 are not consistent with prior positive results from Phase 2 trials of PH94B in social anxiety disorder, we remain committed to transforming the treatment landscape for those living with anxiety, depression, and other central nervous system disorders.

“As part of this commitment, our team will continue to pursue PH94B’s potential as a new treatment option for multiple anxiety disorders — including for both acute treatment for social anxiety disorder in our ongoing PALISADE-2 Phase 3 trial and for continued use in our ongoing Phase 2 trial in adjustment disorder with anxiety.

“We would like to thank the patients and investigators for their participation in the trial, and we will continue to evaluate the detailed data from PALISADE-1 as we move forward with our ongoing trials.”

PALISADE-1 is a multi-centre, randomised, double-blind, placebo-controlled, parallel design, Phase 3 clinical study in adults diagnosed with a social anxiety disorder (SAD).

The Phase 3 trial was designed to evaluate the efficacy, safety, and tolerability of the acute administration of PH94B to relieve symptoms of anxiety in adult patients with SAD.

It evaluates the participants during a simulated public speaking challenge and measures the efficacy, safety, and tolerability of the drug using the patient-reported SUDS.

In addition to PH94B, VistaGen has two other drug candidates in its CNS pipeline, PH10 and AV-101, as potential treatments for anxiety, depression and other CNS disorders.