Vistagen's fasedienol misses primary endpoint in PALISADE-4 trial

Vistagen announced on June 30, 2026 that its PALISADE-4 Phase 3 trial of intranasal fasedienol for the acute treatment of social anxiety disorder did not meet its primary endpoint. In the overall trial population of 238 patients, fasedienol showed a least squares mean change from baseline on the SUDS score of -9.5 (SE 1.7) compared with -11.4 (SE 1.7) for placebo, a difference of 1.9 with p=0.427.¹ There was no treatment difference between fasedienol and placebo for the secondary endpoints.¹

Safety and tolerability data for fasedienol were described as favorable and consistent with previous placebo-controlled trials.¹

In a post-hoc analysis of 123 patients with very severe social anxiety, defined by a baseline Liebowitz Social Anxiety Scale (LSAS) score of 95 or greater, fasedienol showed a mean SUDS change of -12.8 (SE 3.4) versus -3.7 (SE 3.4) for placebo, a difference of -9.1 with p=0.036, reaching nominal statistical significance.¹ The company noted this analysis excluded data from one disqualified site and certain subjects affected by ceiling and placebo effects in the public speaking challenge.

Vistagen said it plans to meet with the FDA to discuss a registrational pathway potentially supported by a single future multi-dose Phase 3 trial using the LSAS as the primary endpoint, with confirmatory evidence from its earlier positive PALISADE-2 trial and other studies in the fasedienol program.¹ This plan is informed by FDA draft guidance published in June 2026 on demonstrating substantial evidence of effectiveness for drugs and biologics.¹

Vistagen said its cash resources are expected to support operations into 2027.¹ The company's broader pipeline includes refisolone for vasomotor symptoms in Phase 2, itruvone for major depressive disorder in Phase 2, PH15 for psychomotor impairment in Phase 2, and PH284 for cancer cachexia in Phase 2.¹