Vanda Pharmaceuticals Inc. (VNDA) said Monday morning that its experimental drug tasimelteon is showing efficacy in blind patients suffering from “Non-24-Hour Disorder,” also called “Non-24-hour sleep-wake syndrome” or “free-running type or non-24-hour circadian rhythm disorder.” Circadian rhythm is another term for an internal biological clock that typically abides to a 24-hour schedule.
Non-24 is one of the rarest and most difficult-to-treat forms of circadian rhythm disorders and affects more than 50 percent of completely blind people in the United States, or 65,000 to 95,000 people. Although uncommon, Non-24 is sometimes also occurs in people with sight, but is far more prevalent in the blind population as there are no light cues to help keep the body balanced in a 24-hour cycle.
Vanda, a biopharmaceutical company focused on the development and commercialization of products for the treatment of central nervous system disorders, said that tasimelteon has been shown for the first time to restore daily cortisol rhythms in totally blind patients suffering from Non-24.
Tasimelteon, an MT1 and MT2 agonist, is currently being tested in two Phase III efficacy studies (SET and RESET) for the treatment of Non-24 in totally blind patients. The latest discoveries were made from the RESET trial treating blind patients with Non-24 with a 20mg dose of tasimelteon daily at bed time for six weeks and then evaluating the rhythms of melatonin and cortisol.
Used as a biomarker in the research, 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, according to the Rockville, Maryland-based Vanda.
"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."
Top-line results from the SET study are expected by the end of 2012 and top-line results from the RESET trial are expected in the first quarter of 2013. Vanda plans to add the data to a New Drug Application to be submitted to the U.S. Food and Drug Administration in the middle of next year.
Shares of VNDA, which spiked from 45 cents to as high as $16.65 in 2009 when the FDA granted marketing approval of Fanapt™ (iloperidone) for the acute treatment of adult patients with schizophrenia, have been sliding ever since; closing trading on Friday at $4.00 per share. Shares are currently about 30 percent off 2012 highs.