Idorsia Pharmaceuticals Japan Ltd, a Sosei Group company, has submitted a new drug application to the Japanese Pharmaceuticals and Medical Devices Agency for the approval of daridorexant, a dual orexin receptor antagonist which has been co-developed with Mochida Pharmaceutical Co Ltd, for the treatment of adult patients with insomnia.
Daridorexant was approved in the US and Europe in January and April 2022, respectively, and is marketed by Idorsia in these and other approved territories as Quvivq.
The new drug application is supported by positive results of a randomized, double-blind, placebo-controlled phase 3 study in Japan to investigate the efficacy and safety of daridorexant. The study met both primary and secondary efficacy endpoints. Daridorexant significantly improved subjective total sleep time, a primary endpoint defined as the change from baseline compared to placebo at 28 days.
Daridorexant also significantly improved sleep onset as measured by a decrease in subjective latency for sleep onset, a primary endpoint defined as the change from baseline compared to placebo at 28 days.
The rate of adverse events was comparable between placebo and daridorexant at both treatment doses. Treatment-emergent adverse events during the double-blind study period were reported in 23.5% and 22.7% of the patients treated with 50 mg and 25 mg daridorexant, respectively (24.4% for placebo).
Sosei Heptares gained Japan and Asia-Pacific rights to daridorexant from Idorsia Pharmaceuticals Ltd in July 2023 in the context of its acquisition of Idorsia Japan and Idorsia Pharmaceuticals Korea Co Ltd.
In December 2019, Mochida and Idorsia Pharmaceuticals Ltd entered into an exclusive license agreement for the co-development and co-marketing of daridorexant for insomnia and related disorders in Japan. Under the agreement, Mochida and Idorsia Japan have jointly developed daridorexant and plan to co-market daridorexant pending Idorsia Japan receiving Japanese approval.
“Insomnia is highly prevalent in Japan and is recognized as an important national health issue. Patients with insomnia have trouble falling or staying asleep, as well as waking up earlier than desired, all of which lead to detrimental effects on both physical and mental health,” says Makoto Uchiyama, MD, PhD, medical advisor of the Japanese phase 3 study, director of Tokyo Adachi Hospital, visiting professor of Nihon University, and visiting professor of Toho University, in a release. “Daridorexant is the first drug for a decade to have been clinically investigated in more than 100 centers in Japan and showed marked positive results in the studies.”
The Japanese phase 3 trial showed that daridorexant increased total sleep time and shortened sleep latency in patients with insomnia without marked hangover symptoms the next morning, which indicates its potency to improve core symptoms of insomnia, according to Uchiyama in the release.
“Such a promising outcome was likely due to the unique characteristics of the drug, a dual orexin receptor antagonist with an optimal elimination half-life,” says Uchiyama in the release.