Vistagen said Monday that patients using its social anxiety drug fasedienol as needed, in real-world settings, kept improving for four months. What the announcement does not change is what happened nearly three months earlier: in the placebo-controlled portion of the same trial, fasedienol missed its primary endpoint, and the numbers moved in placebo’s favor.

What the new data actually measured

The release covers the open-label extension (OLE) of PALISADE-4, the fourth Phase 3 study in Vistagen’s fasedienol program. After the randomized, blinded portion of PALISADE-4 concluded, 322 participants chose to continue into the OLE, taking fasedienol as needed, up to six times a day, in ordinary anxiety-provoking situations instead of a clinic setting. Every participant knew they were receiving the drug; there was no placebo group in this portion of the study.

On the Liebowitz Social Anxiety Scale (LSAS), a clinician-administered measure, mean scores improved steadily: 20.2 points at one month, 24.6 at two, 29.1 at three, and 31.4 at four, against a baseline mean of 99.3, in the “very severe” range. The Social Phobia Inventory, a self-reported measure, showed a similar pattern, improving from 10.5 points at month one to 14.9 at month four. Discontinuation due to adverse events was low, 1.6 percent, and Vistagen reported no new safety signals after up to a year of as-needed use.

What an open-label extension cannot show

None of that establishes that fasedienol caused the improvement. An OLE has no control group, so there is nothing to separate a drug effect from the ordinary pattern of a chronic condition getting better with time, attention, and repeated clinical contact, a pattern well documented in social anxiety disorder research independent of any specific treatment. Participants also self-selected into the extension, and self-selection tends to favor people who found the drug tolerable and were already doing reasonably well.

There is a second, more specific limitation, disclosed in the release’s own footnote: Vistagen closed the OLE early, in July 2026, “for business reasons,” before every participant had the chance to reach the four-month mark. That is why the reported sample shrinks at each interval, from 298 patients at month one to 197 at month four. That shrinkage does not necessarily reflect participants quitting because the drug wasn’t working; the company’s own account attributes it to study closure timing, not dropout. But it does mean the month-four figures describe whichever roughly 60 percent of the original 322 happened to have enrolled early enough to be measured before the cutoff, not the full group followed for a complete four months.

The controlled result from nearly three months earlier

The context the announcement does not restate: in June, Vistagen reported topline results from the randomized, placebo-controlled portion of this same PALISADE-4 trial, and it missed. On the primary endpoint, a single-dose public speaking challenge scored on the Subjective Units of Distress Scale, fasedienol’s least-squares mean change was -9.5 (standard error 1.7), against -11.4 (SE 1.7) for placebo, a difference of 1.9 points that narrowly favored placebo and was not statistically significant (p=0.427). Both secondary endpoints also failed to separate from placebo, and one of the two moved in the wrong direction for the drug as well.

A post-hoc analysis found a nominally significant result in a subgroup of 123 patients with baseline LSAS scores of 95 or higher, the same “very severe” threshold used to describe the OLE population above: a difference of 9.1 points favoring fasedienol (p=0.036). That subgroup was constructed after the fact, and not just by severity. Vistagen also excluded one disqualified trial site and patients showing a ceiling effect or an unusually large placebo response before running the comparison. A post-hoc analysis built on several layered exclusions is weaker evidence than a prespecified result, whatever its p-value; it can generate a hypothesis worth testing prospectively, not confirmation that the underlying effect is real.

A second consecutive miss

PALISADE-4 is not fasedienol’s first controlled setback. The compound’s original Phase 3 study, PALISADE-2, met its primary endpoint in 2023, a statistically significant result (p=0.015) in 141 patients with a lower severity bar for entry (LSAS of at least 70). Its next study, PALISADE-3, missed its primary endpoint in December 2025, in a result Vistagen’s own leadership at the time called unexpected. PALISADE-4 makes it two in a row.

What the company is proposing next

Vistagen says it is preparing to meet with the FDA this quarter to discuss a registrational pathway for fasedienol, built around a single future multi-dose Phase 3 trial using the LSAS as its primary endpoint, rather than the single-dose public speaking challenge design used in PALISADE-3 and PALISADE-4. The company points to PALISADE-2’s earlier result, the very-severe subgroup analysis, and now the open-label extension data as the supporting case. The company has said its cash resources support operations into 2027, without specifying what a new trial would cost or whether existing cash covers it.

What to watch

Whether the FDA agrees that two failed public speaking challenge trials, one earlier controlled success, a post-hoc subgroup built on layered exclusions, and an uncontrolled extension add up to a viable registrational path is not yet resolved. The clearer signal will be the outcome of this quarter’s FDA meeting, and separately, whether Vistagen actually launches and funds the multi-dose trial it says it wants to run. Until a controlled trial produces a prespecified result favoring fasedienol, the open-label data announced Monday describes what happened to patients who knew they were on the drug, not what the drug did.