Nasal spray to treat social anxiety disorder lacks abuse potential: FDA

The FDA has announced that PH94B a new intranasal drug to treat acute social anxiety in adults being produced by VistaGen Therapeutics lacks the potential for abuse

The wave-through by regulators, which VistaGen reported Thursday, is welcome news for the biotech as it advances its nasal spray, PH94B, through two phase 3 trials for social anxiety disorder (SAD). The FDA told VistaGen that clinical and nonclinical data on the candidate show no abuse potential-and as of now, the biotech won't need an additional human study to prove this.

In an interview with Fierce Biotech, VistaGen CEO Shawn Singh called the FDA consensus a "big deal" as the company hopes to create an alternative treatment to benzodiazepines.

"Especially in this space and especially with the history of the drugs that really occupy most of the space within anxiety and depression, especially anxiety with benzos," he said.

Currently, the spray is working its way through two trials, Palisade-1 and -2, that use a public speaking challenge to test the drug's effects. Top-line data are slated for the third quarter and fourth quarter of this year, respectively.

The company hopes to package data from the two trials with a long-term safety study when it applies for approval. The FDA filing would also include data from a dose response study and a dose-redose study to further prove safety; Singh estimated that if all goes well, the company could apply for approval at the end of 2023. 

VistaGen nabs phase 3-ready social anxiety drug from Pherin

The biotech is also working on launching a global Palisade trial alongside China-based AffaMed Therapeutics, which licensed PH94B from VistaGen for China, South Korea and Southeast Asia. Last month, VistaGen said Chinese regulators gave the green light for the trial to launch there. The company intends to recruit patients in Mexico, Canada and South Korea as well.

VistaGen originally snapped up the rights to PH94B from Pherin in 2018 for more than $2 million in unregistered common stock. The spray has become the bedrock of VistaGen's pipeline, and it's in development for five other neurological disorders, including post-traumatic stress disorder and adjustment disorder. The central nervous system-focused company is also testing a second nasal spray, PH10, to treat depression and suicidal thinking.

Looking ahead, Singh noted that PH94B is not out of the woods completely; the FDA reserves the right to circle back on abuse liability even after approval. But Singh is optimistic that VistaGen will continue to strengthen its case that the spray is safe.

"That's why we're comfortable and confident because it's not just based on nonclinical, it's based on both nonclincal and clinical, and the clinical signals of course are of paramount importance," he said. "So that's what every study that we conduct is designed to assess...not just abuse liability [adverse events] but all [adverse events]."