PHARMACOLOGY
Ulipristal acetate is an orally-active synthetic progesterone receptor modulator with a tissue-specific partial progesterone antagonist effect. It exerts a direct action on fibroids, reducing their size by inhibiting cell proliferation and inducing apoptosis.1
CLINICAL STUDIES
In the PEARL I study, women with symptomatic fibroids, excessive uterine bleeding and anaemia were randomised to receive daily treatment for up to 13 weeks with ulipristal acetate 5mg (n=96), 10mg (unlicensed dose; n=98) or placebo (n=48). All patients received oral iron supplementation.2
At 13 weeks, control of uterine bleeding was observed in 91% of women receiving the 5mg dose, 92% of those receiving the 10mg dose and 19% of those on placebo (p<0.001 for both doses vs placebo). Amenorrhoea was reported in 73%, 82% and 6% of women respectively, and occurred within 10 days in the majority of those who received ulipristal acetate. Fibroid volume decreased with ulipristal acetate 5mg and 10mg but increased slightly with placebo: median changes of -21%, -12% and +3%, respectively.2
In the non-inferiority PEARL II study, 307 women with symptomatic fibroids and excessive uterine bleeding were randomised to receive 3 months of daily therapy with ulipristal acetate (5mg or 10mg) or monthly intramuscular injections of leuprorelin (3.75mg).3
At 13 weeks, uterine bleeding was controlled in 90% of patients receiving 5mg ulipristal acetate, 98% of those receiving 10mg ulipristal acetate and in 89% of those receiving leuprorelin. Median times to amenorrhoea were 7 days with 5mg ulipristal acetate, 5 days with 10mg ulipristal acetate and 21 days with leuprorelin. Moderate to severe hot flushes were more common with leuprorelin than ulipristal acetate (p<0.001).3
References
1. Esmya Summary of Product Characteristics, February 2012.
2. Donnez J et al. N Engl J Med 2012; 366: 409-20.
3. Donnez J et al. N Engl J Med 2012: 366: 421-32.
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Further information: Preglem