Tasimelteon (trade name Hetlioz, previously known as BMS-214,778) is a drug approved solely for the treatment of non-24-hour sleep–wake disorder in totally blind people.It was under development for the treatment of insomnia and other sleep disorders. It is a selective agonist for the melatonin receptors MT1 and MT2 in the suprachiasmatic nucleus of the brain, similar to older drugs such as ramelteon. It has been through Phase III trials successfully and was shown to improve both onset and maintenance of sleep, with few side effects.
A year-long (2011–2012) study at Harvard tested the use of tasimelteon in blind subjects with non-24-hour sleep–wake disorder. In May 2013 Vanda Pharmaceuticals submitted a New Drug Application to the Food and Drug Administration for tasimelteon for the treatment of non-24-hour sleep–wake disorder in totally blind people. It was approved by the FDA on January 31, 2014 under the brand name Hetlioz.