Treatment of Uterine Myoma

A review of six clinical trials involving 166 women treated with mifepristone administered in doses of 5-50 mg/day for 3-6 months resulted in reductions in myoma volumes of 26-74%, with rates of amenorrhea of 63-100%. The prevalence and severity of dysmenorrhea, menorrhagia and pelvic pressure was reduced [69]. 

In one of these studies, treatment was extended for up to 1 year in 40 premenopausal women with large symptomatic myoma who received mifepristone in doses of5orl0mg daily [70,71].Mean uterine volumes decreased by 48% in both groups by 6 months and to 53% at 1 year. None of the above trials conducted with mifepristone was placebo-controlled. 

Recently, a randomized double-blind placebo-controlled 26-week study was performed in 42 women with symptomatic myoma. Women randomized to mifepristone 

A small clinical study comprising 30 women was conducted with Proellex and has appeared in the manufacturer s web site, but to date not in a peer-reviewed journal (http //www.reprosrx.com). Doses of 12.5, 25 and 50 mg were compared to 3.75 mg of the gonadotropin-releasing hormone (GnRH) superagonist, Lupron . There was also a placebo group. The response was similar to what had been reported with mifepristone and asoprisnil. 

These studies indicate that PAs and SPRMs both have the ability to decrease myoma size. A crucial question is what happens to the myoma following cessation of treatment To date, no study has adequately assessed this important issue. 

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The PA mifepristone also delays or inhibits ovulation, which may produce amenorrhea [48, 49]. Amenorrhea may be a consequence of an effect at the level of the ovary, pituitary or hypothalamus. The SPRM asoprisnil, in contrast, is not so effective in inhibiting ovulation [50]. The amenorrhea consequent to PAs and SPRMs occurs with levels of estradiol in the range of the early follicular phase of the menstrual cycle [48-50]. As a result ofthe antiproliferative effect and the amenorrhea, PAs and SPRMs have been advocated in the treatment of uterine myoma, endometriosis and dysfunctional uterine bleeding. 

Carbonell JL, Acosta R, Perez Y, Garces R, Sanchez C, Tomasi G. Treatment of uterine myoma with 2.5 or 5 mg mifepristone daily during 3 months with 9 months posttreatment followup randomized clinical trial. ISRN Obstet Gynecol 2013 2013. 649030. 

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