dosage regimen of diaryl sulfide derivatives. The present invention relates to a compound of formula (i) wherein x is o, s, so or so2； R1 is halogen, trialomethyl, -oh, C1-7 alkyl, C1-4 alkoxy, trifluoromethoxy, phenoxy, cyclohexylmethyloxy, pyridylmethoxy, cinnamyloxy, naphthylmethoxy, phenoxymethyl, -ch2-oh, -ch2-ch2-oh, C1-4 alkylthio 4, C 1-4 alkylsulfinyl, C 1-4 alkylsulfonyl, benzylthio, acetyl, nitro or cyano, or phenyl, C 1-4 alkyl or phenyl C 1-4 alkoxy each phenyl group thereof being optionally substituted by halogen, C 1-3, C 1-4 alkyl -4 or C 1-4 alkoxy； R 2 is h, halogen, trialomethyl, C 1-4 alkoxy, C 1-7 alkyl, phenethyl or benzyloxy； R3 is h, halogen, C1-3, oh, C1-7 alkyl, C1-4 alkoxy, benzyloxy, phenyl or C1-4 alkoxymethyl； each of r4 and r5 independently is h or a residue of formula (a) wherein each of r8 and r9 independently is h or C1-4 alkyl optionally substituted by halogen, n is a number from 1 to 4； or a pharmaceutically acceptable salt, hydrate, solvate, isomer, or prodrug thereof； or a compound of formula (ii) wherein R 1a is halogen, trialomethyl, C 1-4 alkyl, C 1-4 alkoxy, C 1-4 alkylthio, C 1-4 alkylsulphinyl, C 1-4 alkylsulfonyl, aralkyl, phenoxy or aralkyloxy optionally substituted ； R 2a is h, halogen, trialomethyl, C 1-4 alkyl, C 1-4 alkoxy, aralkyl or aralkyloxy； R3a is h, halogen, C1-3, C1-4 alkyl, C1-4 alkoxy, C1-4 alkylthio or benzyloxy； R4a is h, optionally substituted C1-4 alkyl, phenyl, benzyl or benzoyl, lower aliphatic C1-5 acyl； R 5a is h, monoalomethyl, C 1-4 alkyl, C 1-4 alkoxymethyl, C 1-4 alkylthiomethyl, hydroxyethyl, hydroxypropyl, phenyl, aralkyl, alkenyl or C 2-4 alkynyl； R6a is h or C1-4 alkyl； R7a is h, C1-4 alkyl or a residue of formula (a) as defined above, xa is o, s, so or so2； and na is an integer from 1 to 4； or a pharmaceutically acceptable salt, hydrate, solvate, isomer, or prodrug thereof for use in a method of treatment, optionally an autoimmune condition, wherein said compound of formula (i) or (ii) is a
