TiumBio (KRX: 321550.KQ), a clinical-stage biopharmaceutical company focused on discovering and developing innovative therapeutics for patients with rare and incurable disease, today announced that Merigolix (code name: TU2670, Daewon's code name: DW4902) has successfully met the primary endpoint of reducing heavy menstrual bleeding in a Phase 2 clinical trial for uterine fibroids. In this trial, Merigolix demonstrated statistically significant improvements across all dosage groups compared to placebo in patients with uterine fibroids.

Merigolix is an investigational, once-daily, oral gonadotropin-releasing hormone (GnRH) receptor antagonist. Unlike traditional GnRH agonists, which require injection and often lead to an initial hormone surge, Merigolix offers a more patient-friendly oral administration without an initial hormonal flare, providing a faster onset of action and improved treatment adherence.

The Phase 2 clinical trial of Merigolix in uterine fibroids was conducted by TiumBio's partner, Daewon Pharmaceutical, and enrolled a total of 71 women diagnosed with uterine fibroids. Participants were randomly assigned to receive high, medium, or low doses of Merigolix, or placebo, administered orally once daily for 12 weeks, followed by a 12-week observation period. The results showed that Merigolix led to statistically significant improvements in heavy menstrual bleeding (HMB)—a validated clinical endpoint—across all dosage groups compared to the placebo.

In addition to the primary endpoint, Merigolix demonstrated statistically and clinically meaningful improvements in several key secondary endpoints, including fibroid size reduction, increased hemoglobin levels (indicating improved anemia), and relief of pelvic pain. The safety and tolerability profile of Merigolix was consistent with prior clinical data, with no new safety signs.

The mechanism of action of Merigolix can be used in various disorders, including endometriosis, uterine fibroids, ART, precocious puberty, and prostate cancer. Notably, in a separate Phase 2 clinical trial for endometriosis completed in 2024, Merigolix also showed excellent therapeutic efficacy and safety, further reinforcing its potential as a promising new treatment.

"We are very excited that Merigolix has demonstrated excellent therapeutic efficacy not only in endometriosis but also in uterine fibroids," said Hun-Taek Kim, Ph.D., MBA, CEO of TiumBio. "successfully achieving both efficacy and safety in Phase 2 significantly increases the probability of regulatory approval and licensing opportunities. We plan to accelerate development and expand into the global uterine fibroid treatment market," he added.

"Uterine fibroids are a condition that causes significant suffering for many women, and we believe Merigolix has the potential to become an important new oral treatment that addresses this unmet medical need," said Jonathan In Baek, President of Daewon Pharmaceutical. "We are pleased with the positive results in uterine fibroids and will continue our efforts to provide patients with a convenient and effective new treatment option," he continued.

Uterine fibroids are benign tumors that develop in the uterus, primarily affecting women of reproductive age, particularly those in their 30s and older. The condition has a high prevalence rate of approximately 20% among women over the age of 35. The most common symptom is heavy menstrual bleeding, but it can also cause abnormal uterine bleeding, pelvic pain, and anemia.

Meanwhile, TiumBio entered into a licensing agreement with Daewon Pharmaceutical in 2019, granting Daewon the rights to develop and commercialize Merigolix in South Korea.