Novel intranasal therapy shows signal in very severe social anxiety disorder

Clinical takeaway: The findings do not change current management of social anxiety disorder but may redirect future studies of intranasal fasedienol toward repeated dosing in patients with very severe disease, using established measures of overall symptom severity rather than anxiety during a single public speaking challenge.

Although the phase 3 PALISADE-4 trial of investigational intranasal fasedienol failed to meet its primary or secondary endpoints in adults with social anxiety disorder (SAD), a post hoc analysis identified a potential benefit in patients with very severe disease, prompting the company to pursue a revised development strategy.

The randomized, placebo-controlled trial evaluated a single dose of fasedienol administered intranasally before a simulated public speaking challenge in 238 adults with SAD. In the overall study population, fasedienol did not significantly reduce anxiety compared with placebo. However, among patients with very severe SAD at baseline, a post hoc analysis found a nominally significant improvement in distress scores during the public speaking challenge. Because this analysis was conducted after the trial was completed, the findings should be considered exploratory.

The company noted that fasedienol remained well tolerated, with a safety profile consistent with previous placebo-controlled studies.

The results do not change current practice, however, they suggest that patients with more severe disease may warrant focused study and highlight the challenges of measuring acute treatment effects using laboratory-based anxiety challenges.

Vistagen plans to meet with FDA to discuss a revised registration pathway. Rather than pursuing an indication for acute treatment before anxiety-provoking events, the company intends to evaluate repeated dosing in a future phase 3 trial using the Liebowitz Social Anxiety Scale, a standard measure of overall disease severity, as the primary endpoint.

“The results of the primary analysis of PALISADE-4 were not what we had hoped for. However, we are encouraged by the safety and tolerability data and our post-hoc analysis in which we observed a positive efficacy signal in a large subpopulation of patients with very severe social anxiety disorder,” said Dr. Angel Angelov, Chief Medical Officer of Vistagen. “As we look at the totality of data across the fasedienol development program, we believe there is evidence of fasedienol’s therapeutic potential for patients with social anxiety disorder.”

Source: Vistagen. (2026, June 30). Topline and Post-Hoc Data from PALISADE-4 Phase 3 Public Speaking Challenge Trial of Fasedienol for the Acute Treatment of Social Anxiety Disorder