VistaGen finds open-label success with social anxiety nasal spray, but PALISADE pivotal trial remains iced

VistaGen’s beleaguered social anxiety spray may be back on hold, but that hasn’t stopped the biotech from touting separate open-label data that the company says show the therapy is safe and will work on an as-needed basis.

Thursday, the company reported that its social-anxiety-treating nasal spray, PH94B, was safe and well tolerated among treated patients in an open-label extension of the phase 3 trial. Patients used the spray as needed up to four times a day. The company says the safety data were consistent irrespective of the number of administered doses. 

VistaGen also touted “clinically meaningful” improvement in patients' social anxiety as measured by the Liebowitz Social Anxiety Scale (LSAS). VistaGen reported that patients’ scores “continued to decline in consecutive months during the study.”

The LSAS measures a person's social anxiety based on how much fear and avoidance they experience doing various tasks such as talking on the phone in public to speaking with an authority figure. VistaGen CEO Shawn Singh said in a release that the results reflect an optimal dosing regimen if the nasal spray is approved. 

The open-label trial data disclosed Thursday are separate from the phase 3 PALISADE-2 trial that VistaGen elected to pause last month. The company paused that trial while it worked to hammer out details with the FDA. In an interview with Fierce Biotech, CEO Shawn Singh confirmed that the trial remained halted. 

"I want to get some comfort from the agency on the continuing validity and reliability of the Liebowitz scale," he said. 

At the time of the self-imposed PALISADE-2 pause, VistaGen hinted that it planned to lobby the FDA to greenlight a new trial using a primary endpoint that focused on improvement in LSAS scores rather than success in a public speaking challenge. The company said that LSAS scores were the primary endpoint for all three approved treatments for social anxiety disorder. 

"We know there's historical precedent, and that scale—it's a really good fit," Singh said. "Because it really does a lot to give confidence about how a drug can affect the lives of people affected by this disorder."

If the FDA gives the go-ahead on using LSAS as the primary endpoint, Singh said that a new phase 3 trial would need "either partnering or financing or both." A spokesperson later added that it's possible such a trial could launch before the end of the year. 

Meanwhile, news of PH94B’s open-label success comes after the company closed its acquisition of Pherin Pharmaceuticals. PH94B, along with VistaGen’s other nasal spray to treat depression, were originally licensed from Pherin. The acquisition gave VistaGen full intellectual property over the assets and dismantled any future royalty payments. 

Editor's note: This story was corrected to reflect that future work on VistaGen's Palisade-2 trial is not contingent on either financing or partnering. CEO Shawn Singh was referring to a third phase 3 trial.