Ulipristal acetate (CDB-2914) is an orally active, selective progesterone receptor modulator (SPRM). Ulipristal acetate stimulates the autophagic response selectively in leiomyoma cells. Ulipristal acetate has the potential for benign gynecological conditions treatment, such as uterine myoma[2].In Vitro: Ulipristal acetate (0.1-5 μM; 96 hours) stimulates autophagy in leiomyoma cells. Ulipristal-induced expression changes of the autophagic markers LC3 and p62/SQSTM1. Ulipristal up-regulates Atg7 protein in leiomyoma cells[2].
Ulipristal acetate blocks activin A modulation of fibronectin and vascular endothelial growth factor A (VEGF-A) mRNA expression in cultured myometrial and leiomyoma cells.In Vivo: Ulipristal and CDB-4124 have significant antiprogestational activity in vivo.
Ulipristal acetate decreases incidences of fibroadenomas and adenocarcinomas in the mammary gland in all treated groups. Ulipristal acetate exposure [AUC(0-24h)] at the highest dose in rats is 67 times human therapeutic exposure at 10 mg/day. In mice, no tumor of any type increases at Ulipristal acetate exposures up to 313 times of therapeutic exposure. Ulipristal acetate-related findings in mice are limited to organ weight changes in the liver, pituitary, thyroid/parathyroid glands, and epididymis as well as minimal panlobular hepatocellular hypertrophy in male and female mice receiving 130 mg/kg/day.
Ulipristal acetate (1 mg/kg and 5 mg/kg) increases the frequency with which pathologists assessed the endometrium as being thickened compared to controls in a dose-dependent manner. There is a slight decrease in secretory differentiation with increasing dose of Ulipristal acetate, with small decreases in frequency of sub- and supra-nuclear vacuolation.