Vistagen announced that PH80, one of the Company?s five investigational neuroactive nasal sprays, demonstrated statistically significant improvement versus placebo in an exploratory Phase 2A study for acute management of the symptoms of premenstrual dysphoric disorder (PMDD), including negative mood and physical and behavioral symptoms. The previously unreported randomized, double-blind, placebo-controlled Phase 2A clinical study of PH80 was designed to explore the efficacy, safety, and tolerability of intranasal administration of PH80 for the acute management of PMDD in subjects with a regular menstrual cycle and at least a one-year history of PMDD. The initial study visit occurred after the onset of symptoms. All subjects were administered placebo nasal spray and those who showed no symptom improvement were eligible to return for the second visit, which occurred after the onset of symptoms during the next menstrual cycle. At the second study visit, subjects were randomized to receive a single dose of 0.9 µg PH80 nasal spray or placebo in the clinic.

Subsequent doses of PH80 or placebo were then self-administered at home as-needed, up to four times per day for six consecutive days prior to the estimated day of menses onset. PH80 demonstrated statistically and clinically significant improvement versus placebo in symptoms of PMDD using the subject-rated Penn Daily Symptom Report (DSR) as early as Day 4 and continuing to Day 6. At Day 6, change from baseline was -12.1 for PH80 (n=29) versus -7.6 for placebo (n=23) (p=0.008), showing significant and clinically meaningful improvement. PH80 also demonstrated statistically and clinically significant improvement versus placebo at Day 6 on the clinician-rated Premenstrual Tension Scale (PMTS) total score where the PH80 change from baseline was -12.0 versus -7.7 for placebo (p=0.006).

PH80 was well-tolerated with no serious adverse events (AEs). The most common AE was headache, reported by 17% in the placebo group and 7% in the PH80 group. No other treatment-emergent AE occurred more than once per subject.

Analysis of the data revealed that mood symptoms seemed to be the most sensitive to PH80: Depression/feeling sad or blue was reported by 0% of PH80 and 68% of placebo-treated subjects; Irritability/persistent anger was reported by <3% of PH80 and 43% of placebo-treated subjects; Anxiety/tension/on edge was reported by 0% of PH80 and 35% of placebo-treated subjects; and Difficulty concentrating was reported by 0% of PH80 and 18% of placebo-treated subjects. This previously unreported exploratory Phase 2A study of PH80 was sponsored by Pherin Pharmaceuticals (Pherin), now a wholly owned subsidiary of Vistagen, and conducted in a real-world setting in Mexico in 2005 and 2006. Vistagen gained access to the results of the study in connection with its acquisition of Pherin in February 2023.

Ellen Freeman, Ph.D., formerly of the University of Pennsylvania, served as the Principal Investigator of the study. Vistagen recently entered into an exclusive negotiation agreement with Fuji Pharma Co. Ltd. regarding a potential license to develop and commercialize PH80 in Japan, including for the acute treatment of moderate to severe hot flashes due to menopause and potentially other indications.

Vistagen?s pipeline includes six clinical-stage drug candidates, including its most advanced neuroactive pherine nasal spray, fasedienol (PH94B), for which Vistagen recently reported positive top-line results from its PALISADE-2 Phase 3 trial in social anxiety disorder.