Vilaprisan in women with uterine fibroids: the randomized phase 2b ASTEROID 1 study

Abstract

To assess the safety and efficacy of four vilaprisan doses (0.5-4.0mg) in women with uterine fibroids. Randomized, double-blind, placebo-controlled, multicenter trial. Ninety-eight centers in 12 countries. Women aged 18-50years with uterine fibroids and heavy menstrual bleeding were randomized equally to oral vilaprisan at 0.5, 1.0, 2.0, or 4.0mg or placebo once daily. Treatment for 12weeks, 24-week follow-up. Primary end point was absence of scheduled or unscheduled bleeding/spotting. Key secondary efficacy end points included volume of menstrual blood loss and change in fibroid volume. A total of 309 patients were randomized, and 300 received treatment. Complete absence of bleeding/spotting was observed in 30%, 56%, 54%, and 60% of patients in the vilaprisan 0.5, 1.0, 2.0, and 4.0mg groups, respectively, versus 1.7% with placebo. After 12weeks, >83% of women achieved amenorrhea (<2mL/28days) with ≥1.0mg vilaprisan versus 9% with placebo. Heavy menstrual bleeding stopped (but returned at a lower volume after treatment cessation) with ≥1.0mg vilaprisan treatment. Reductions in fibroid volume of up to 41% were observed. Most patients receiving vilaprisan reported improvements in symptom severity. No safety concerns were identified in general safety, endometrial safety (by biopsy), laboratory values, and ultrasound examinations. ASTEROID 1 supports the efficacy of vilaprisan for the treatment of heavy menstrual bleeding associated with uterine fibroids. Daily oral treatment with vilaprisan 0.5-4.0mg was well tolerated, and vilaprisan 2.0mg once daily has been selected for further investigation. NCT02131662.