FDA Approves Vanda’s Treatment of Nighttime Sleep Disturbances in Smith-Magenis Syndrome

Rare Daily Staff

The U.S. Food and Drug Administration approved Vanda Pharmaceuticals’ Hetlioz capsule and liquid formulations for the treatment of adults and children, respectively, with nighttime sleep disturbances associated with Smith-Magenis Syndrome.

Smith-Magenis Syndrome (SMS) is a rare neurodevelopmental disorder characterized by an “inverted” circadian rhythm that makes it difficult for patients with SMS to sleep during the night. It is caused by a small deletion of human chromosome 17p. In more rare cases SMS is caused by a point mutation in the RAI1 gene, which resides in the deleted region. SMS is estimated to affect 1 in 15,000-25,000 births in the United States. SMS is usually not inherited but rather is due to a de-novo deletion. Patients with SMS often have a number of physical, mental and behavioral problems, but the most common symptom is a severe sleep disorder associated with significant disruption in the lives of patients and their families.

Hetlioz (tasimelteon) is a melatonin receptor agonist and is the first FDA-approved medication for patients with SMS. Hetlioz already has marketing authorization from the FDA and the European Medicines Agency for the treatment of people with Non-24-Hour Sleep-Wake disorder.

“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,” said Mihael Polymeropoulos, president and CEO, Vanda Pharmaceuticals. “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 SMS was based on a single placebo-controlled efficacy study in 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 SMS.

Hetlioz capsules for adults with SMS will be immediately available and the liquid formulation for children with SMS is expected to be available in the first quarter of 2021.

Photo: Mihael Polymeropoulos, president and CEO, Vanda Pharmaceuticals