A compound selected fromn4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]benzamide;4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]-N,N-dimethylbenzamide;(11β,17β)-17-hydroxy-11-{4-[(4-methylpiperazin-1-yl)carbonyl]phenyl}-17-(pentafluoroethyl)estra-4,9-dien-3-one;tert-butyl-4-{4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]benzoyl}piperazine-1-carboxylate;(11β,17β)-17-hydroxy-17-(pentafluoroethyl)-11-[4-(piperidin-1-ylcarbonyl)phenyl]estra-4,9-dien-3-one;methyl-1-{4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]benzoyl}piperidine-4-carboxylate;N-[2-(dimethylamino)ethyl]-4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]benzamide;N-[3-(dimethylamino)propyl]-4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]benzamide;N-[2-(dimethylamino)ethyl]-4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]-N-methylbenzamide;methyl-2-({4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]benzoyl}amino)benzoate;4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]-N-(pyridin-2-yl)benzamide;4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]-N-(pyridin-3-yl)benzamide;4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]-N-[3-(morpholin-4-yl)propyl]benzamide;4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]-N-(pyridin-4-yl)benzamide;(11β,17β)-17-hydroxy-17-(pentafluoroethyl)-11-[4-(pyrrolidin-1-ylcarbonyl)phenyl]estra-4,9-dien-3-one;4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]-N-(2-phenylethyl)benzamide;4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]-N-(2-phenylpropan-2-yl)benzamide;4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]-N-(4-sulphamoylbenzyl)benzamide;N-ethyl-4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]benzamide;4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]-N-(pyridin-2-ylmethyl)benzamide;4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]-N-(pyridin-4-ylmethyl)benzamide;4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]-N-phenylbenzamide;4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]-N-(2-methoxyphenyl)benzamide;4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]-N-(3-methoxyphenyl)benzamide;4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]-N-(4-methoxyphenyl)benzamide;N-(4-chlorophenyl)-4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]benzamide;N,N-diethyl-4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]benzamide;4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]-N-methyl-N-phenylbenzamide;(11β,17β)-17-hydroxy-11-[4-(morpholin-4-ylcarbonyl)phenyl]-17-(pentafluoroethyl)estra-4,9-dien-3-one;(11β,17β)-17-hydroxy-17-(pentafluoroethyl)-11-{4-[(4-phenylpiperazin-1-yl)carbonyl]phenyl}estra-4,9-dien-3-one;4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]-N-methyl-N-(pyridin-2-ylmethyl)benzamide;4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]-N-methyl-N-(pyridin-3-ylmethyl)benzamide;4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]-N-methyl-N-(pyridin-4-ylmethyl)benzamide;N-benzyl-4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]benzamide;4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]-N-(4-methoxybenzyl)benzamide;N-(4-chlorobenzyl)-4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]benzamide;N-(2-acetamidoethyl)-4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]benzamide;methyl-4-({4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]benzoyl}amino)benzoate;(11β,17β)-11-[4-(3,4-dihydroisoquinolin-2(1H)-ylcarbonyl)phenyl]-17-hydroxy-17-(pentafluoroethyl)estra-4,9-dien-3-one;(11β,17β)-11-{4-[(4-benzylpiperazin-1-yl)carbonyl]phenyl}-17-hydroxy-17-(pentafluoroethyl)estra-4,9-dien-3-one;N-(4-carbamoylphenyl)-4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]benzamide;N-cyclopropyl-4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]benzamide;4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]-N-methyl-N-(2-phenylethyl)benzamide;(11β,17β)-17-hydroxy-17-(pentafluoroethyl)-11-(4-{[4-(2-phenylethyl)piperazin-1-yl]carbonyl}phenyl)estra-4,9-dien-3-one;(11β,17β)-17-hydroxy-17-(pentafluoroethyl)-11-(4-{[4-(pyridin-4-yl)piperazin-1-yl]carbonyl}phenyl)estra-4,9-dien-3-one;(11β,17β)-17-hydroxy-17-(pentafluoroethyl)-11-(4-{[4-(pyrazin-2-yl)piperazin-1-yl]carbonyl}phenyl)estra-4,9-dien-3-one;(11β,17β)-11-[4-({4-[2-(dimethylamino)ethyl]piperazin-1-yl}carbonyl)phenyl]-17-hydroxy-17-(pentafluoroethyl)estra-4,9-dien-3-one;(11β,17β)-17-hydroxy-17-(pentafluoroethyl)-11-[4-({4-[2-(pyrrolidin-1-yl)ethyl]piperazin-1-yl}carbonyl)phenyl]estra-4,9-dien-3-one;(11β,17β)-17-hydroxy-17-(pentafluoroethyl)-11(4-{[4-(pyridin-4-ylmethyl)piperazin-1-yl]carbonyl}phenyl)estra-4,9-dien-3-one;4-[(11β,17(3)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]-N-methyl-N-[2-(pyridin-2-yl)ethyl]benzamide;N-benzyl-4-[(11β,17(3)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]-N-methylbenzamide;N-(4-acetamidophenyl)-4-[(11β, 17(3)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]benzamide;4-[(11β,17(3)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]-N-(3-methoxybenzyl)benzamide;4-[(11β,17(3)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]-N-[2-(pyrrolidin-1-yl)ethyl]benzamide;4-[(11β,17(3)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]-N-[2-(pyridin-3-yl)ethyl]benzamide;N-(3-chlorobenzyl)-4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]benzamide;methyl-3-({4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]benzoyl}amino)benzoate;4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]-N-methyl-N-[2-(pyridin-4-yl)ethyl]benzamide;N-(cyclopropylmethyl)-4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]benzamide;4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]-N-[4-(phenylcarbamoyl)phenyl]benzamide;4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]-N-[2-(pyridin-2-yl)ethyl]benzamide;4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]-N-[2-(4-methylpiperazin-1-yl)ethyl]benzamide;(11β,17β)-17-hydroxy-17-(pentafluoroethyl)-11-{4-[(4-phenylpiperidin-1-yl)carbonyl]phenyl}estra-4,9-dien-3-one;4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]-N-[2-(pyridin-4-yl)ethyl]benzamide;(11β,17β)-11-{4-[(4-benzoylpiperazin-1-yl)carbonyl]phenyl}-17-hydroxy-17-(pentafluoroethyl)estra-4,9-dien-3-one;4-{4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]benzoyl}-N,N-dimethylpiperazine-1-carboxamide;(11β,17β)-17-hydroxy-11-(4-{[4-(methylsulphonyl)piperazin-1-yl]carbonyl}phenyl)-17-(pentafluoroethyl)estra-4,9-dien-3-one;(11β,17β)-17-hydroxy-17-(pentafluoroethyl)-11-(4-{[4-(pyridin-2-ylmethyl)piperazin-1-yl]carbonyl}phenyl)estra-4,9-dien-3-one;(11β,17β)-17-hydroxy-17-(pentafluoroethyl)-11-(4-{[4-(pyridin-3-ylmethyl)piperazin-1-yl]carbonyl}phenyl)estra-4,9-dien-3-one;methyl-4-{4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]benzoyl}piperazine-1-carboxylate;2-(4-{4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]benzoyl}piperazin-1-yl)-N-methylacetamide;4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]-N-methyl-N-[2-(pyridin-3-yl)ethyl]benzamide;(11β,17β)-17-hydroxy-17-(pentafluoroethyl)-11-[4-(piperazin-1-ylcarbonyl)phenyl]estra-4,9-dien-3-one;(11β,17β)-11-{4-[(4-acetylpiperazin-1-yl)carbonyl]phenyl}-17-hydroxy-17-(pentafluoroethyl)estra-4,9-dien-3-one;1-{4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]benzoyl}piperidine-4-carboxylic acid;2-({4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]benzoyl}amino)benzoic acid;3-({4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]benzoyl}amino)benzoic acid;4-({4-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]benzoyl}amino)benzoic acid; and4⬲-[(11β,17β)-17-hydroxy-3-oxo-17-(pentafluoroethyl)estra-4,9-dien-11-yl]biphenyl-4-carboxamide;or a salt thereof.