Esmya® and the PEARL studies: A review.

Ulipristal acetate was investigated in four phase 3 trials. In PEARL I, ulipristal produced significant normalisation of blood loss within 1 week and decreased fibroid volume. In PEARL II, ulipristal produced faster and more consistent control of bleeding than leuprorelin acetate and had a more favourable side-effect profile. Ulipristal-induced decreases in fibroid volume persisted for 6 months, whereas fibroids regrew after leuprorelin was stopped. PEARL III showed that ulipristal was effective during long-term treatment, with norethisterone further reducing the magnitude of bleeding in the off-treatment period. PEARL IV investigated ulipristal over four cycles, finding little difference between 5 and 10 mg ulipristal, further changes in menstruation and fibroid volume with repeat courses, and no increase in side effects.