WASHINGTON, Oct. 15, 2012 /PRNewswire/ -- Vanda Pharmaceuticals (NASDAQ: VNDA), a biopharmaceutical company focused on the development and commercialization of products for the treatment of central nervous system disorders, reported today that tasimelteon has been shown for the first time to restore daily cortisol rhythms in totally blind patients suffering from Non-24-Hour Disorder (Non-24). Tasimelteon was previously reported to entrain the 24-hour rhythm of melatonin secretion in patients with Non-24. Cortisol is a key regulatory hormone which exhibits a circadian rhythm, rising in the early morning and falling in the evening. The circadian regulation of the cortisol rhythm is necessary for the human body to be prepared for a wide range of daily activities and physiologic functions, including blood pressure variation, utilization of fatty acids, circulating lymphocytes and immunity. A growing body of data suggests that tasimelteon's entraining effects are accomplished through a direct resetting of the master body clock, located in the suprachiasmatic nucleus (SCN) of the hypothalamus. Tasimelteon is a circadian regulator in development for the treatment of Non-24 in totally blind individuals. "It is particularly noteworthy that tasimelteon can entrain the diurnal cortisol rhythm," said Dr. Fred Turek, Director of the Center for Sleep & Circadian Biology at Northwestern University, "because it is an endocrine rhythm that is tightly regulated by the master clock in the SCN, indicating that tasimelteon is acting on the central circadian clock in humans." "We have confirmed that the circadian dyssynchrony seen in Non-24 extends beyond the melatonin rhythm and the sleep-wake cycle and into the dyssynchrony of the fundamental diurnal variation of endocrine system function as exemplified by the circadian rhythm of cortisol," said Mihael H. Polymeropoulos, MD, President and CEO of Vanda. "Tasimelteon's effect on both melatonin and cortisol rhythms further confirms its potential to reset the master body clock and address the circadian dyssynchrony which is inherent in Non-24." This observation was made during an open-label segment of Vanda's RESET study. RESET is a Phase III study of the maintenance effect of tasimelteon in the treatment of Non-24. Totally blind patients with Non-24 were given a 20mg dose of tasimelteon daily at bed time for 6 weeks. The rhythms of melatonin and cortisol were assessed longitudinally in urine samples. Entrainment of the cortisol rhythm by tasimelteon was directly associated with entrainment of the melatonin rhythm in the same patients. Vanda believes that the simultaneous entrainment of both melatonin and cortisol suggests that tasimelteon can reset the master body clock in the SCN through binding to MT1 and MT2 melatonin receptors. Tasimelteon's unique balanced melatonin receptor binding profile may make it well-suited to perform as a circadian regulator.