Vanda Pharmaceuticals' (VNDA) phase 3 study of Hetlioz in adults with delayed sleep-wake phase disorder met its primary endpoint, shifting sleep onset 37 minutes earlier than placebo, the company said late Tuesday.

The study also showed 60% of patients on Hetlioz advanced sleep timing by at least 30 minutes versus 15% on placebo, while safety findings were consistent with the drug's existing label, Vanda said.

The company plans to submit a supplemental new drug application with the US Food and Drug Administration for approval.

The drug is currently approved in the US for the treatment of non-24-hour sleep-wake disorder and for the treatment of nighttime sleep disturbances in Smith-Magenis syndrome.