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

aimTo assess the efficacy and safety of long-term intermittent administration of 10-mg ulipristal acetate (UPA) for symptomatic uterine fibroids in Japanese women.

methodsOpen-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.

resultsOf 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.

conclusionsLong-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.