The present invention relates to novel cyclic N,N'-diarylureas and N,N'-diarylthioureas - androgen receptor antagonists, anti-cancer agent, pharmaceutical composition, medicament, and method for treatment of cancerous diseases, among them prostate cancer. Cyclic N,N' -diarylthioureas or N,N' -diarylureas of the general formula 1, their optical (R)- and (S)- isomers and pharmaceutically acceptable salts thereof exhibiting properties of androgen receptor antagonists have been proposed, wherein: X represents oxygen or sulfur； m = 0 or 1； R1 represents C 1 -C 3 alkyl； R2 and R3 represent hydrogen； or R2 and R3 together with C-atom they are attached to form C = O group； R4 and R5 represent hydrogen； or R4 represents hydrogen, R5 represents methyl； or R4 represents methyl, R5 represents CH 2 R6 group in which R6 represents C 1 -C 3 alkoxycarbonyl, carboxyl, hydroxyl group optionally substituted with methyl or benzyl； or R4 and R5 together with C-atom they are attached to form 5- or 6- membered heterocycle comprising at least one oxygen atom or nitrogen atom optionally substitutd with methyl； or R4 and R5 together with C-atom they are attached to form NH group.
