Ulipristal Acetate: a Novel Option for the Medical Management of Symptomatic Uterine Fibroids

Fibroids, the most common tumor in women of reproductive age, impact negatively on women’s health and quality of life, and have significant cost implications for their management. The current mainstay treatments are surgical (myomectomy and hysterectomy) and more recently radiological (UAE and focused ultrasound surgery). Hysterectomy is curative but precludes future fertility, whereas the impact of the other treatments on reproduction is uncertain. With women in Western societies deferring childbearing to their 30s and 40s, when fibroids are most symptomatic, there is a pressing need for a uterus-sparing medical therapy that is cheap, effective, and enhances reproductive potential. Serendipity and meticulous translational research has shown that progesterone augments fibroid proliferation, raising the possibility that progesterone receptor modulators could inhibit fibroid growth; this research has culminated in the emergence of ulipristal acetate (UA), a first-in-class, oral selective progesterone receptor modulator (SPRM) that has successfully completed phase III clinical trials. It has been licensed in Western Europe for short-term clinical use prior to surgery, and has shown efficacy with a significant reduction in uterine bleeding, fibroid volume, and improved quality of life, without the side effects associated with other medications such as gonadotropin-releasing hormone (GnRH) agonists. As with all new medicines, there are concerns surrounding UA, not least its effect on the endometrium and the long-term impact on general health and reproduction. Research to date has tended to be industry led, and therefore, there is a need for researcher/clinician-led studies to address the wider issues concerning SPRMs. UA may not turn out to be the “Holy Grail” of medical therapy in the treatment of symptomatic uterine fibroids, but it has rightly given cause for a huge optimism. Further laboratory and clinical research into PRMs and related compounds will no doubt lead to more refined medications.