Vistagen has announced that the Phase 3 PALISADE-4 public speaking challenge study of intranasal fasedienol (PH94B) for the treatment of social anxiety disorder failed to meet its primary endpoint. In December 2025, the company announced that the PALISADE-3 trial, which had a similar protocol to PALISADE-4, had failed to meet its primary endpoint.
In 2022, the Phase 3 PALISADE-1 public speaking challenge trial had also failed to meet its primary endpoint, and the PALISADE-2 study was then paused. The following year, Vistagen said that PALISADE-2, which enrolled 141 out of an expected 208 subjects, had met its primary endpoint.
According to Vistagen, the PALISADE-4 trial demonstrated that the nasal spray “was nominally statistically significant” on one measure in a subpopulation of subjects “with very severe social anxiety defined by a baseline score at screening of 95 or greater on the Liebowitz Social Anxiety Scale.” The company now says it plans to meet with the FDA “to discuss a registrational pathway for fasedienol potentially supported by a single, future multi-dose Phase 3 trial with the LSAS as the primary endpoint.”
Vistagen President and CEO Shawn Singh commented, “Vistagen remains focused on being financially disciplined and evaluating opportunities to maximize the value of our deep pipeline of clinical-stage product candidates. We plan to meet with the FDA with the goal of establishing a clear registrational path forward for fasedienol. I want to express my sincere gratitude to the patients, coordinators, investigators, and the Vistagen team whose dedication and commitment made this work possible.”
Chief Medical Officer Angel Angelov said, “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. 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.”
Vistagen points out that its pipeline of intranasal pherines acquired along with Pherin Pharmaceuticals in 2022, includes refisolone (PH80) for the treatment of hot flashes, itruvone (PH10) nasal spray for the treatment of major depressive disorder, PH15 for “psychomotor impairment due to mental fatigue,” and PH284 for muscle wasting due to cancer.
Read the Vistagen press release
