Results of a Japan Phase III Clinical Trial of the GnRH Antagonist Linzagolix in Patients with Uterine Fibroids - Primary Endpoint has been Achieved -

Kissei Pharmaceutical Co., Ltd. (Head Office: Matsumoto, Nagano, Japan; Chairman and CEO: Mutsuo Kanzawa; "Kissei") announced today the results of two domestic Phase III clinical trials (KLH2301 and KLH2302) of the GnRH receptor antagonist Linzagolix (generic name; development code in Japan: KLH-2109; "the Product") in patients with uterine fibroids. KLH2301 study showed non-inferiority and KLH2302 study showed superiority to the control group and met their primary endpoints.

KLH2301 was a double-blind, active controlled study in which 287 patients with uterine fibroids who experienced hypermenorrhea were treated for 24 weeks with either the Product or an existing GnRH receptor agonist.
The study showed non-inferiority of Product to the control group in the primary endpoint of "the percentage of patients with a total PBAC score of less than 10, from 6 to 12 weeks after treatment with the study drug". The incidence of adverse drug reactions was similar to that of the control group, and no new safety concerns were identified.

KLH2302 was a double-blind, placebo-controlled, comparative study of 89 patients with uterine fibroids who had hypermenorrhea and pain symptoms and who received either the Product or placebo for 12 weeks.
The study's primary endpoints, "the percentage of patients with a total PBAC score of less than 10, from 6 to 12 weeks after treatment with the study drug" and "the percentage of patients with a maximum NRS score of 1 or less for pain symptoms in the 28 days before the end of treatment with the study drug," showed superiority of the Product group over the placebo group. The incidence of adverse drug reactions was similar to that in the KLH2301 study, and no new safety concerns were identified.

Detailed results of these studies are currently being analyzed.

Kissei will continue its efforts to make Linzagolix available to patients with uterine fibroids as soon as possible.

《 Reference 》

About Linzagolix (KLH-2109)
This orally available GnRH (gonadotropin-releasing hormone) antagonist antagonizes GnRH at the GnRH receptor in the pituitary gland and suppresses the secretion of gonadotropin, a gonadotropin, thereby reducing estrogen production in the ovaries.

About Uterine Fibroids
Uterine fibroids is a benign tumor that develops in the smooth muscle that makes up the uterine myometrium and grows in a sex hormone-dependent manner. It has been reported that hypermenorrhea and chronic pain symptoms have a significant impact on patients' quality of life (QOL).

About the Pictorial Blood Loss Assessment Chart (PBAC) Score
The PBAC score is based on the degree of menstrual blood adherence to sanitary products, the number of times they are used, and the size and number of clots. If the amount of blood on the napkin or tampon after use is small, the score is 1 point; if it is moderate, 5 points; if it is large, 20 points for the napkin (10 points for the tampon); if the blood clots are up to 2 cm, 1 point; if they are over 3 cm, 5 points; if blood leaks from the napkin or tampon in use, 5 points are added. If the total points in one menstruation exceeds 100 points, more than 80 ml of bleeding is expected which is a sign of hypermenorrhea.

About the Numerical Rating Scale (NRS) score
Pain is rated from "no pain (0 point)" to "maximum pain thinkable (10 point)" in total of 11 steps each with a rating score.