Vanda Pharmaceuticals Inc. (VNDA) has sought FDA approval for the expanded use of its sleep disorder drug Hetlioz to include the treatment of insomnia and a decision is due on March 4, 2024.Hetlioz secured FDA approval for the treatment of Non-24-Hour Disorder in adults in 2014, and for nighttime sleep disturbances in Smith-Magenis Syndrome in patients 16 years of age and older in 2020.Earlier this month, the FDA notified the company that it has identified deficiencies in the supplemental New Drug Application for Hetlioz in the treatment of insomnia characterized by difficulties with sleep initiation. However, the regulatory agency has not disclosed the deficiencies at this time.The net product sales of Hetlioz declined to $100.2 million for the full year 2023, from $159.7 million for the full year 2022, hurt by the at-risk launch of generic versions of the drug in the U.S.VNDA closed Tuesday's (Feb.27, 2024) trading at $4.59, up 0.66%.