Vistagen Therapeutics, Inc. announced positive results from a Phase 2A pilot study of PH15, an investigational pherine nasal spray, for improvement of psychomotor impairment caused by mental fatigue. PH15 demonstrated a statistically significant improvement in reaction time compared to placebo and caffeine in sleep-deprived study participants. The previously unreported randomized, double-blind, placebo-controlled, crossover Phase 2A pilot study of PH15 was designed to explore the efficacy, safety, and tolerability of intranasal administration of PH15 on psychomotor performance as measured by reaction time in sleep-deprived participants.

Ten participants were randomly administered PH15 (multiple 1.6 µg doses, total dose of 9.6 µg), placebo (nasal spray and oral), or caffeine (single 400 mg oral dose administered 1 hour before the session) in sequential sleep deprivation study sessions spaced one week apart. During each sleep deprivation session, participants received blinded treatments before the start of each of four testing periods, at 6:00 p.m., 9:00 p.m., midnight, and 3:00 a.m. The participants? reaction times to both isochronous (regular interval) and stochastic (random interval) ?flash?

light stimuli were computer-measured during each testing period as participants responded to the luminous stimuli. Statistically Significant Efficacy: During both isochronous and stochastic reaction time tests, administration of 1.6 µg PH15 nasal spray induced a significantly faster mean reaction time compared to placebo nasal spray across all time points (p<0.001). PH15 also demonstrated a statistically significant improvement in reaction time compared to oral caffeine (p<0.001) for both reaction time tests during the testing periods at midnight and 3:00 a.m. when subjects were most fatigued.

Well-tolerated Therapy: PH15 was well-tolerated with no serious adverse events reported. The adverse event profiles of PH15 and placebo were comparable, with brief nasal itching in one PH15-dosed participant and three placebo-dosed subjects. Participants on oral caffeine, however, experienced palpitations, euphoria, dry mouth, stomachache, and polyuria.