Social anxiety disorder is treatable with drugs, but these older medications typically take a long time to start working and they don’t work well for everyone. Vistagen Therapeutics is developing a drug with a different mechanism of action than currently available medications and it now has data showing the fast-acting nasal spray therapy met a pivotal study’s main goal of reducing the distress people feel from public speaking.
The preliminary Phase 3 data reported for the drug, fasedienol, sent shares of South San Francisco-based Vistagen soaring. The biotech’s stock price opened up more than 1,000% on Monday before settling down and closing at $13.05, a 676% increase over Friday’s closing price.
Fasedienol works by employing pherines, synthetic neuroactive steroids. When administered as a nasal spray, the drug is intended to target chemosensory neurons found in the nasal cavity. Doing so connects to neurons involved in the development of social anxiety disorder and potentially other anxiety and mood disorders, Vistagen explained in regulatory filings.
The randomized, placebo-controlled Phase 3 study enrolled participants with a social anxiety disorder diagnosis and a baseline score of at least 70 on the Liebowitz Social Anxiety Scale (LSAS). On this scale, which goes from 0 to 79, a higher score indicates greater social anxiety. Subjects were randomly assigned to receive the Vistagen drug or a placebo, both of which were self-administered before a five-minute public speaking challenge. During this challenge, participants were asked their social anxiety score, which was recorded by a trained observer. This process was repeated for multiple weekly visits, which occurred for three to seven weeks depending on the participant.
Fasdienol met the study’s main goal of showing a reduction in the Subjective Distress Scale (SUDS), which is another scale used to assess anxiety. According to Vistagen, patients who received the experimental therapy showed an average 13.8 point reduction in score compared to an 8.0 average reduction in the placebo group. The drug also met a secondary goal of showing a statistically significant difference as measured according to yet another scale.
The new fasedienol results come with some caveats. Last year, Vistagen reported its drug failed a different Phase 3 test measured according to SUDS. Much of this study was conducted during the height of the Covid-19 pandemic, a time marked by stress for study participants and staff turnover at the contract research organization running the trial. In regulatory filings, the company pointed to these dynamics as a possible reason for the negative trial result. In addition to the additional stress, the company said impaired nasal cell function from Covid-19 may have affected the ability of some participants to respond to the therapy.
The results reported Monday are from PALISADE-2, a separate Phase 3 study that began in the fall of 2021. This study had a targeted enrollment of 324, but the latest results are from just 141 participants. Vistagen paused the study last year to allow independent biostatisticians to conduct an interim analysis. The analysis did not conclude that the study would be futile, but Vistagen opted to close it “given the expense, time and methodological complexities in resuming PALISADE-2.”
Investors clearly welcomed Vistagen’s preliminary results for fasedienol. But with one failed pivotal clinical trial and another positive but incomplete Phase 3 study, Vistagen needs more data and money to press ahead. In its report of fiscal 2023 financial results in late June, Vistagen said it had positive FDA feedback for a planned Phase 3 test that could support a new drug application for fasedienol in social anxiety disorder. Rather than using the public speaking challenge, this study would assess patients according to LSAS as the main goal of the clinical trial.
Vistagen’s cash position at the end of its fiscal year ended March 31 was just $16.6 million, though the company might take advantage of its soaring stock price to sell more shares. In the meantime, Vistagen said additional data analysis of PALISADE-2 is ongoing and the company plans to present the results at future scientific meetings.
“We are thrilled that these compelling topline results from the Phase 3 PALISADE-2 trial confirm what was seen in the Phase 2 studies in social anxiety disorder and highlight the potential for fasedienol, with its novel and unique proposed mechanism of action, to transform what is possible for more than 25 million people living with social anxiety in the U.S. and millions more affected worldwide,” CEO Shawn Singh said in a prepared statement.
Photo: Adam Taylor, Getty Images
