Disclosed is a progesterone receptor antagonist compound of formula I, wherein: R1 can be a hydrogen atom and R2 a hydroxyl group or R1 and R2 together can be an oxo group. Specific compounds disclosed include: 11beta-[4-(1,2-dihydroxyethyl)phenyl]-20,20,21,21,21-pentafluoro-17-hydroxy-19-nor-17alpha-pregna-4,9-dien-3-one； and 20,20,21,21,21-pentafluoro-17-hydroxy-11beta-[4-(hydroxyacetyl)phenyl]-19-nor-17alpha-pregna-4,9-dien-3-one. Further disclosed is a pharmaceutical composition comprising a compound of formula I, and the use of the compound of formula I in the manufacture of a medicament for the treatment of endometriosis, myomas, hormone-dependent tumours, or for female contraception.
