TiumBio Co., Ltd. announced positive topline results from its Phase 2a clinical trial of Merigolix, an oral gonadotropin-releasing hormone (GnRH) receptor antagonist, in patients with moderate to severe endometriosis-associated pain. The trial achieved its primary endpoint of reducing dysmenorrhea scores compared to placebo across all three dose groups, demonstrating a statistically significant difference (120mg group p=0.044, 240mg group p=0.001, 320mg group p<0.001). The study enrolled 86 female patients with moderate to severe endometriosis-associated pain across five European countries to evaluate the efficacy and safety of Merigolix in endometriosis.

The patients were randomized to receive either Merigolix 120 mg, Merigolix 240 mg, Merigolix 320 mg, or a placebo once daily (QD) for 12 weeks. The change in endometriosis-associated pain from baseline to 12 weeks of treatment was assessed by measuring the mean dysmenorrhea score using the Numeric Rating Scale (NRS) over the past month. As a result of that, Merigolix achieved statistically significant and clinically meaningful improvements in mean dysmenorrhea scores from baseline compared to the placebo group at all tested doses: -4.3 point at the 120 mg dose (p=0.044), -5.4 point at the 240 mg dose (p=0.001), and -6.2 point at the 320 mg dose (p<0.001), while the placebo group reported -2.7 point.

Merigolix was generally well tolerated, with no serious treatment-related adverse events, consistent with prior studies. The most commonly reported adverse events in the study population were hot flush, headache, and nausea. Merigolix is an orally active non-peptide GnRH antagonist for the treatment of endometriosis and uterine fibroids.

Merigolix offers improved convenience of administration and safety compared to conventional GnRH agonists. According to GlobalData, the endometriosis market will reach approximately $2.7 billion in 7 major countries (US, Germany, France, Italy, UK, Spain, Japan) by 2030. It is forecasted that GnRH antagonist therapies will replace existing treatments, accounting for about 70% of the total endometriosis market.

Endometriosis is a disorder in which the endometrial tissue that line the inside of the uterus grows out the uterus and is known to cause severe pelvic pain, menstrual pain, lower abdominal pain, and infertility which occurs in about 10-30% of women in childbearing age. It is estimated to affect approximately 200 million patients worldwide.