June 30 (Reuters) - Vistagen Therapeutics VTGN.O said on Tuesday its experimental anxiety disorder drug failed to meet the main goal of a late-stage trial testing its ability to reduce symptoms in adults during a simulated public-speaking challenge, sending its shares down nearly 70% in premarket trading.

The drug, fasedienol, did not achieve a statistically significant improvement over placebo for the main goal of the trial, which enrolled 238 adults with social anxiety disorder, Vistagen said.

• The company also reported no meaningful difference between fasedienol and placebo on key secondary measures in the overall trial population.

• A post-hoc analysis showed fasedienol improved symptoms in 123 patients with very severe social anxiety disorder, Vistagen said.

• Social anxiety disorder is a mental health condition affecting more than 30 million U.S. adults that is marked by intense fear and distress in social or performance situations, according to the company.

• The drug's safety and tolerability profile was consistent with previous studies, with no new concerns identified, the biotech firm said.

• Vistagen plans to shift its focus from treating short-term anxiety symptoms to broader treatment of social anxiety disorder over time.

• It also said it plans to meet with the U.S. Food and Drug Administration to discuss a potential approval pathway that could involve a single future late-stage trial using the Liebowitz Social Anxiety Scale, a measure of social anxiety severity, as the primary endpoint.

• Vistagen's current cash resources are expected to support operations into 2027, the biotech firm said.