Kissei Pharmaceutical gains Japan approval for uterine fibroid drug Yselty

Kissei Pharmaceutical Co., Ltd. announced today that it has obtained manufacturing and marketing approval from the Ministry of Health, Labour and Welfare for its GnRH antagonist Yselty® Tablets 100mg, indicated for uterine fibroids. This approval follows the submission of the application in February 2025, based on results from domestic Phase III clinical trials (KLH2301 and KLH2302) for uterine fibroids.

Yselty® (linzagolix choline) is an orally administered GnRH antagonist that reduces estrogen production, thereby improving symptoms of uterine fibroids such as excessive menstruation, lower abdominal pain, back pain, and anemia. Uterine fibroids affect over 70% of women, primarily in their 30s and 40s, significantly impacting their quality of life. The Ministry of Economy, Trade and Industry estimates the annual loss of labor productivity due to menstrual complications, including uterine fibroids, at approximately 570 billion yen.

Internationally, Yselty® was launched in Germany in September 2024 by Theramex and is undergoing launch preparations in other European countries. Synmonsa BioPharma received marketing approval in Taiwan in October 2025, with JW Pharma developing it in South Korea and Searchlight Pharma in Canada. Kissei's consolidated financial results forecast for the fiscal year ending March 31, 2026, remains unchanged.