The US Food and Drug Administration (FDA) has approved Vanda Pharmaceuticals Inc's HETLIOZ (tasimelteon) capsule and liquid formulations for the treatment of adults and children with nighttime sleep disturbances associated with Smith-Magenis Syndrome (SMS). Smith-Magenis Syndrome is a rare neurodevelopmental disorder, a defining feature of which is an "inverted" circadian rhythm, making it extremely difficult for patients with SMS to sleep during the night. HETLIOZ is the first FDA-approved medication for patients with SMS. "The FDA approval of HETLIOZ for the treatment of nighttime sleep disturbances in SMS would not have been accomplished without the heroic efforts of SMS patients and the efforts of their families and advocates supporting the recruitment, design, and conduct of the study," says Mihael H. Polymeropoulos, MD, Vanda's president and CEO, in a release. "We remain committed to providing this much-needed therapy to patients with SMS." The approval of HETLIOZ for the treatment of nighttime sleep disturbances in Smith-Magenis Syndrome was based on a single placebo-controlled efficacy study in this rare disorder, which studied both adults with SMS taking the HETLIOZ capsule and children with SMS taking the liquid formulation. The safety profile of HETLIOZ in this study was similar to those seen in HETLIOZ studies previously conducted for the treatment of Non-24-Hour Sleep-Wake Disorder, and was similar between adults and children with Smith-Magenis Syndrome. [RELATED: HETLIOZ Improves Sleep Quality in Patients with Smith-Magenis Syndrome, Finds Clinical Study] "We are very excited to see HETLIOZ, the first ever treatment approved for people with SMS, addressing the significant problem of sleep disturbances and we are happy to see this treatment used in our community," says Maggie Miller, co-founder and vice president of PRISMS (Parents and Researchers Interested in Smith-Magenis Syndrome), in a release. "We thank Vanda and the FDA for partnering to help our community and we look forward to continued partnership to bring this important therapy to families with SMS." HETLIOZ capsules, for adults with Smith-Magenis Syndrome, will be immediately available and the HETLIOZ LQ liquid formulation, for children with SMS, is expected to be available in the first quarter of 2021.