Key results from two phase 3 trials on the efficacy and safety of daridorexant in patients with chronic insomnia

This plain language summary describes the main results from two similar research studies, “Study 1” and “Study 2”, which evaluated the use of a medication called daridorexant in patients with chronic insomnia disorder. These two studies were phase 3 clinical trials, which compared different doses of daridorexant to an inactive pill called a placebo, which looked and tasted similar to the daridorexant pill but did not contain daridorexant or any other active ingredient. Adults with chronic insomnia disorder typically find it hard to fall or stay asleep and may wake up too early, leading to sleep dissatisfaction. They also have impaired daytime functioning, which is when a person can feel tired or drowsy, have difficulty concentrating, or experience low mood as a consequence of lack of sleep. Adults with chronic insomnia disorder are also at increased risk for injuries and accidents as a result of that impaired daytime functioning. Researchers found that daridorexant 50 mg and 25 mg improved on average participants' ability to get to sleep and stay asleep, as well as increasing their overall total sleep time. Daridorexant 50 mg also improved daytime functioning without any negative effects the next morning, such as feeling tired or drowsy, on average in the participants included in the studies. While available medications are effective in treating night-time symptoms of insomnia, they have not been shown to improve daytime symptoms in insomnia, and in many cases have been shown to have residual effects the next day due to their nature as sedatives. Therefore there has been a need for new treatments for chronic insomnia disorder that will improve both night-time and daytime symptoms with minimal next morning effects. These findings show the effectiveness of daridorexant 50 mg in improving both night-time and daytime functioning, and that daridorexant is well-tolerated at all doses. The results from these two studies resulted in the approval of the 25 mg and 50 mg doses of daridorexant by the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA). Clinical Trial Registration: NCT03545191 (study 1) and NCT03575104 (study 2) ( ClinicalTrials.gov )