After a bout of bad luck, Vistagen’s social anxiety spray has puffed out a phase 3 win—data that have sent the biotech's stock soaring.
The study, dubbed PALISADE-2, evaluated the efficacy, safety and tolerability of fasedienol—also called PH94B—a nasal spray designed to treat adults with social anxiety disorder (SAD). Fasedienol hit the trial’s primary endpoint, demonstrating a statistically significant improvement in the average score on a standardized distress scale during a public speaking challenge compared to placebo, according to data shared Aug. 7.
The trial also met its secondary endpoint, showing a statistically significant change in clinician-determined improvement between fasedienol and placebo participants. Fasedienol was also found to be well-tolerated with a favorable safety profile, according to Vistagen.
The biotech’s stock skyrocketed 1,272% from market close Friday, rising from $1.68 per share to $24.70 as the market opened Monday. The stock has evened out a bit since then, hitting $12.07 per share at 11 a.m. ET.
Vistagen touts the data as the “first positive phase 3 study” of an investigational therapy for social anxiety disorder in the U.S. in more than 15 years. But the data was never a sure thing, with the social anxiety asset plagued with problems over the past few years.
Previously, after seeing two rival social anxiety disorder candidates flunk phase 2 studies, the biotech paused plans for PALISADE-2 and fasedienol pending talks with the FDA.
The California biotech’s asset had failed a prior phase 3 trial—known as PALISADE-1—in patients with SAD. Due to that failure, the company brought on independent biostatisticians to perform an interim analysis of PALISADE-2.
The biostatisticians gave Vistagen the green light to resume the study without making changes to the design, but the biotech balked. Vistagen later revealed that further analysis of the failed trial led to proposed amendments to PALISADE-2 intended to address issues that may have contributed to the disappointing data generated in the earlier study. External data then gave Vistagen fresh questions about the impact of the proposed changes to the protocol, leading to talks with the FDA about the design.
While holding off on the trial, Vistagen shared data in March from an open-label phase 3 study assessing the spray in patients with SAD. The company said the data show the therapy is safe and will work on an as-needed basis.
It appears the biotech is still looking to launch another pivotal trial of fasedienol for patients with SAD before heading to the FDA, this time with a different primary endpoint.
At the time of the self-imposed PALISADE-2 pause, VistaGen hinted that it planned to ask the FDA to approve a new trial using a primary endpoint that focused on improvement in Liebowitz Social Anxiety Scale (LSAS) scores, a scale that measures an individual’s social anxiety based on how much fear and avoidance they experience doing various tasks. The company said that LSAS scores were the primary endpoint for all three approved treatments for social anxiety disorder.
“We have a nice and fluid dialogue with the agency,” Vistagen CEO Shawn Singh told Fierce Biotech. “And we're constantly thinking of ways how we can most efficiently find a way to get this drug to patients.”
A future phase 3 study testing “multiple administrations of fasedienol over several weeks on a patient-tailored, as-needed basis” will build on the data Vistagen already has, Michael Liebowitz, M.D., LSAS creator and managing director of the Medical Research Network, said in the company release.
Editor’s note: This article was updated at 1:45 p.m. ET on Aug. 7 to include commentary from Vistagen CEO Shawn Singh and additional context.