Vistagen’s investigational nasal spray for social anxiety disorder did not significantly outperform placebo in a Phase 2 study, according to data presented on Aug. 7. The drug, known as fasedienol, was tested in a mid-stage trial involving 61 patients who were randomly assigned to receive either a single dose of fasedienol followed by placebo, two doses of fasedienol, or two placebo sprays. The interventions were administered ten minutes apart.
The results showed that neither dosing regimen of fasedienol led to significant improvements over placebo in self-assessed distress and anxiety during a public speaking challenge. When the results from both fasedienol groups were pooled, there was still no significant advantage compared to the placebo group.
Vistagen said, “The study was not designed to demonstrate statistically significant differences between treatment groups.” However, the company conducted a prespecified analysis focusing on patients with very severe social anxiety at baseline. In this subset, pooled data from both fasedienol groups showed nominally significant improvement over placebo during the public speaking test. A repeat dose still failed to show statistical superiority over placebo. Exploratory analyses indicated nominally significant improvements in anticipatory anxiety among patients receiving double-dose fasedienol.
Chief Medical Officer Angel Angelov said Thursday that “the broad body of clinical evidence” supporting fasedienol “will help inform our discussions with the FDA regarding a potential registrational pathway” for the drug. Despite these efforts, William Blair questioned Vistagen's decision to proceed after revealing earlier that its Phase 3 PALISADE-4 trial had also failed to show efficacy for easing distress during public speaking challenges.
William Blair wrote in an investor note Thursday, “The most intriguing data out of PALISADE-4 was a signal observed in severe patients,” but added that even this analysis is difficult “to gain conviction around . . . given its post-hoc nature and several caveats.”
Despite these setbacks and limited funding—$45.4 million as of March 31—Vistagen plans further discussions with the Food and Drug Administration about next steps for potential registration.
