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

ASTEROID 1 (phase 2b) supports the efficacy and safety of vilaprisan for treatment of uterine fibroids, and 2.0 mg vilaprisan is the selected dose.

Volume 111, Issue 2, Pages 240–248


Linda D. Bradley, M.D., Sukhbir S. Singh, M.D., James Simon, M.D., Kristina Gemzell-Danielsson, Ph.D., Kathrin Petersdorf, M.D., Esther Groettrup-Wolfers, M.D., Xiaowei Ren, M.S., Michal Zvolanek, M.D., Christian Seitz, M.D.



To assess the safety and efficacy of four vilaprisan doses (0.5–4.0 mg) in women with uterine fibroids.


Randomized, double-blind, placebo-controlled, multicenter trial.


Ninety-eight centers in 12 countries.


Women aged 18–50 years with uterine fibroids and heavy menstrual bleeding were randomized equally to oral vilaprisan at 0.5, 1.0, 2.0, or 4.0 mg or placebo once daily.


Treatment for 12 weeks, 24-week follow-up.

Main Outcome Measure(s)

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 4.0 mg groups, respectively, versus 1.7% with placebo. After 12 weeks, >83% of women achieved amenorrhea (<2 mL/28 days) with ≥1.0 mg vilaprisan versus 9% with placebo. Heavy menstrual bleeding stopped (but returned at a lower volume after treatment cessation) with ≥1.0 mg 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 0.5–4.0 mg was well tolerated, and vilaprisan 2.0 mg once daily has been selected for further investigation.

Clinical Trial Registration Number



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