The US Food and Drug Administration (FDA) has accepted for review the New Drug Application (NDA) for lemborexant, an investigational agent being studied for the treatment of insomnia, a sleep-wake disorder. A Prescription Drug User Fee Act (PDUFA) date is set for December 27, 2019.

The NDA submission was based on data from the clinical development program including two Phase 3 studies of lemborexant—SUNRISE 1 (Study 304) and SUNRISE 2 (Study 303).

SUNRISE 1: a one-month Phase 3 clinical study to evaluate the efficacy and safety of lemborexant versus placebo and versus an active comparator (zolpidem tartrate extended release, “zolpidem ER”) in 1,006 patients 55 years and older (45% of all patients were aged 65 years and older) with insomnia disorder. This study assessed sleep latency (using latency to persistent sleep; primary objective), sleep efficiency, and wake after sleep onset (effect on maintaining sleep; key secondary objectives) objectively using polysomnography, and achieved its primary and key secondary objectives. The most common adverse events reported in the lemborexant arms were headache and somnolence.

SUNRISE 2: a 12-month, placebo-controlled (first six months) Phase 3 clinical study to evaluate the long-term efficacy and safety of lemborexant in 949 adult patients (18 to 88 years of age) with insomnia disorder. This study evaluated subjective (patient-reported) sleep onset latency (primary objective), sleep efficiency, and wake after sleep onset (key secondary objectives) using sleep diaries, and achieved its pre-specified primary and key secondary efficacy objectives. The most common adverse events reported in the lemborexant arms were somnolence, nasopharyngitis, headache, and influenza.

“Our ultimate goal for the development of a sleep-wake treatment is to bring to patients living with insomnia a new option that has the potential to improve their ability to fall asleep, stay asleep, and wake well the next morning,” says Lynn Kramer, MD, chief clinical officer and chief medical officer, Neurology Business Group, Eisai, in a release. “This milestone for lemborexant brings us one step closer to addressing unmet needs for millions of patients who experience insomnia.”

John Renger, PhD, vice president, head of research & development and regulatory affairs, Imbrium Therapeutics, says, “Insomnia, a disorder of poor sleep quality, delayed onset, or insufficient quantity, causes impairment in functioning and has been correlated with long-term consequences for health and well-being. We are dedicated to working with our partner Eisai to make this investigational treatment available to patients, pending regulatory approval.”

Lemborexant is being jointly developed by Eisai and Imbrium Therapeutics for the treatment of multiple sleep-wake disorders, including insomnia. Information about ongoing clinical studies is available at clinicaltrials.gov.