The Phase 2 study was small and was not designed to establish the statistical difference between Vistagen’s drug candidate and placebo, according to Vistagen. The biotech plans to meet with the FDA to determine a registrational path for the asset.
Vistagen’s investigational nasal spray, even when given as a double-dose minutes apart, did not significantly outperform placebo in a Phase 2 social anxiety disorder study.
The asset, dubbed fasedienol, is being assessed in a mid-stage study that enrolled 61 patients. Participants were randomly assigned to receive a single dose of fasedienol followed by a placebo spray; two doses of fasedienol or two placebo sprays. Across all three treatment arms, interventions were given 10 minutes apart.
Data presented on Thursday showed that neither fasedienol dose arms significantly improved self-assessed distress and anxiety versus placebo during a public speaking challenge. Pooling results from both fasedienol groups likewise demonstrated no significant advantage over placebo.
“The study was not designed to demonstrate statistically significant differences between treatment groups,” Vistagen said in its news release. The company nevertheless ran a prespecified analysis of the data, focusing on patients with very severe social anxiety at baseline.
In this follow-on analysis, pooled fasedienol data were nominally significantly better than placebo at easing distress during the public speaking test. A repeat dose of the drug, however, still failed to statistically outperform placebo. Exploratory analyses, meanwhile, pointed to nominally significant improvements in anticipatory anxiety in patients on double-dose fasedienol.
With these data, Vistagen appears emboldened to approach the FDA, with CMO Angel Angelov noting on Thursday that “the broad body of clinical evidence” backing fasedienol “will help inform our discussions with the FDA regarding a potential registrational pathway” for the drug.
William Blair, however, questioned the wisdom of this decision. In June, Vistagen revealed that the Phase 3 PALISADE-4 study had failed, with fasedienol unable to ease distress during a public speaking challenge. As in the case of Thursday’s mid-stage readout, the nasal spray candidate elicited nominally significant benefits on patients with severe social anxiety disorder (SAD) at baseline.
“The most intriguing data out of PALISADE-4 was a signal observed in severe patients,” the firm wrote in a note to investors on Thursday. “And even this analysis is challenging to gain conviction around . . . given its post-hoc nature and several caveats to the analysis.”
There might be hope yet for Vistagen though, “given the high unmet need in SAD and the agency’s desire to curb the use of benzodiazepines in the indication,” William Blair said. “We believe the agency will be amenable to a path forward here, though we are unsure if a single additional study will be sufficient for filing or if the agency will request two additional pivotal studies.”
As of March 31, Vistagen had $45.4 million in cash, equivalents and marketable securities, enough to keep going into 2027—but insufficient, according to William Blair, to fund another Phase 3 trial for fasedienol.
