Phase III long‐term study to evaluate the efficacy and safety of ulipristal acetate in Japanese patients with uterine fibroids

AIM: To assess the efficacy and safety of long‐term intermittent administration of 10‐mg ulipristal acetate (UPA) for symptomatic uterine fibroids in Japanese women. METHODS: Open‐label, noncomparative study (Japan Primary Registries Network identifier: JapicCTI‐173737) conducted at 32 gynecological centers (November 2017–December 2019). Premenopausal women diagnosed with uterine fibroids associated with heavy menstrual bleeding received three 12‐week courses of 10‐mg UPA once daily. Amenorrhea, fibroid volume, endometrial histology, and safety were assessed. RESULTS: Of 155 patients enrolled, 140 received ≥1 dose of UPA and were analyzed. Across all courses, the rates of patients with amenorrhea for 35 days were >90%, and >99% of patients achieved uterine bleeding normalization. Median time to amenorrhea after each course started was 4–5 days; menstruation returned after treatment within a median of 25–27 days. Mean changes in fibroid volume from baseline were −21.5%, −31.4%, and −35.0% for Courses 1, 2, and 3, respectively. Patients experienced sustained improvements in anemia, pain, and quality of life during treatment. Most adverse events were mild/moderate in severity and decreased in frequency with each course. Seven serious adverse events (six patients) were reported; anemia, embolic cerebral infarction, and pituitary apoplexy (one patient each) were considered UPA‐related. Nonphysiological changes in endometrial histology were transient and benign. No safety concerns were detected in hormone concentrations or liver function tests. CONCLUSIONS: Long‐term administration of 10‐mg UPA is effective for reducing symptoms associated with uterine fibroids in Japanese women. UPA was well tolerated and few safety concerns were reported.