Daewon Pharmaceutical said its investigational drug DW-4902 (ingredient: merigolix), licensed from TiumBio, met the primary endpoint of reducing heavy menstrual bleeding in a phase 2 clinical trial for uterine fibroids.

Daewon Pharmaceutical licensed the development rights for merigolix in Korea from TiumBio in 2019.

The study enrolled 71 women diagnosed with uterine fibroids, who were randomly assigned to one of four groups receiving high, medium, or low doses of merigolix, or placebo.

Patients took the oral drug once daily for 12 weeks, followed by a 12-week observation period. The results demonstrated that all dosage groups achieved statistically significant reductions in heavy menstrual bleeding compared to placebo.

Secondary endpoints—including fibroid size reduction, increased hemoglobin levels indicating improved anemia, and pain relief—also showed marked improvements.

Merigolix is an oral gonadotropin-releasing hormone (GnRH) antagonist. Unlike conventional GnRH agonists, which can cause an initial hormone surge at the start of treatment, merigolix provides a rapid therapeutic effect without triggering a hormonal spike.

Also, while most GnRH agonists require injection, merigolix offers greater patient convenience and treatment adherence through oral administration.

The drug’s mechanism of action suggests potential applications beyond uterine fibroids, including endometriosis, assisted reproductive technology (ART), and precocious puberty. merigolix has already demonstrated promising efficacy and safety in a European phase 2 trial for endometriosis.

“Uterine fibroids cause significant suffering for many women. As an oral treatment option, merigolix has the potential to become an important new drug for this condition,” Daewon Pharmaceutical CEO Baek In-hwan said. “We will continue efforts to provide patients with convenient and effective therapies.”

TiumBio CEO Kim Hun-taek also said, “Following merigolix’s success in endometriosis, the drug has now also shown strong efficacy in uterine fibroids.”

Having met both efficacy and safety goals in the critical phase 2 trial, TiumBio plans to pursue global development targeting the international uterine fibroid treatment market, Kim added.

Uterine fibroids are benign tumors originating in the uterus, primarily affecting women over 30. Among women aged 35 and older, the prevalence rate is approximately 20 percent. Heavy menstrual bleeding is the most common symptom, often accompanied by abnormal uterine bleeding, pelvic pain, and anemia.

According to Global Market Insights, the global uterine fibroid treatment market was valued at approximately 2.5 trillion won ($1.7 billion) in 2022 and is projected to reach 6.6 trillion won by 2032.