Eisai Co Ltd and Purdue Pharma LP report positive topline results from SUNRISE 2, a long-term Phase 3 efficacy and safety evaluation of lemborexant, an investigational agent for sleep-wake regulation currently being studied for the potential treatment of multiple sleep-wake disorders. Topline results reported are the primary and key secondary outcomes of the study from the 6-month, placebo-controlled treatment period; the study is ongoing to 12 months. Eisai and Purdue Pharma plan to present full results from SUNRISE 2 at upcoming medical meetings in 2019.

SUNRISE 2 enrolled more than 900 adult patients (18 to 88 years of age) with insomnia disorder, characterized by difficulty falling asleep and/or staying asleep. The study met the pre-specified primary and key secondary efficacy objectives assessed by patient self-reports (sleep diaries). At the end of the 6-month, placebo-controlled treatment period, lemborexant 5 mg and 10 mg provided statistically significant improvement in subjective sleep onset latency compared to placebo, the study’s primary endpoint. Lemborexant 5 mg and 10 mg also provided statistically significant improvement in sleep maintenance variables of subjective sleep efficiency and subjective wake after sleep onset compared to placebo, which were the study’s key secondary endpoints. The most common adverse event, greater than 5% in either lemborexant treatment arm and greater than placebo, were somnolence, headache, and influenza. Overall discontinuation rates due to adverse events were comparable between placebo and lemborexant 5 mg, and higher for lemborexant 10 mg.

“As a clinician and researcher treating patients with insomnia and other sleep-wake disorders for 30 years, for me, successful treatment means that patients fall asleep fast, sleep well, and wake well, without functional impairment, or loss of effect over time,” says Russell Rosenberg, PhD, DABSM, a principal investigator in the lemborexant studies, in a release. “The results of SUNRISE 2 are particularly encouraging for the many patients who suffer from chronic insomnia.”

The results of SUNRISE 2 build on a growing body of knowledge supporting the development of lemborexant, including SUNRISE 1, a recently completed Phase 3 study of lemborexant 5 mg and 10 mg versus placebo, that included a superiority comparison to zolpidem tartrate extended release (zolpidem ER) as a secondary endpoint, as well as key safety studies.

Lynn Kramer, MD, chief clinical officer and chief medical officer, neurology business group, Eisai, says, “Our aspiration for lemborexant is to bring to the millions of patients suffering from insomnia and other sleep-wake disorders an agent for sleep-wake regulation that improves their ability to fall asleep and stay asleep, and maintains efficacy over time. In SUNRISE 2, lemborexant improved both time to sleep onset as well as sleep maintenance over a 6-month period. With these results, we now look forward to proceeding with regulatory submissions for lemborexant to bring to patients a long-term treatment option for treating the sleep-wake disorder, insomnia.”

Lemborexant acts on the orexin neurotransmitter system and is believed to regulate sleep and wake by dampening wakefulness without impeding the ability to awaken to external stimuli.

“We understand the importance of sleep-wake regulation to overall health and patient outcomes and, alongside our collaboration partner, Eisai, look forward to continued research as part of our commitment to a variety of patient populations with sleep-wake disorders,” says Marcelo Bigal, MD, PhD, chief medical officer, Purdue Pharma.

Discovered by Eisai, lemborexant is being jointly developed by Eisai and Purdue Pharma.

This article discusses investigational uses of an agent in development and is not intended to convey conclusions about efficacy or safety. There is no guarantee that such an investigational agent will successfully complete clinical development or gain health authority approval.