Novel substituted indoloquinoxalines of formula (I wherein R1 is hydrogen or represents one or more similar or different substituents in the positions 7 to 10 selected from the group halogen, lower alkyl/alkoxy, hydroxy, trifluoromethyl, trichloromethyl, trifluoromethoxy, R2 represents similar or different C1-C4 alkyl substituents, X is CO or CH2, Y is OH, NH2, NH—(CH2)n—R3 wherein R3 represents lower alkyl, OH, NH2, NHR4 or NR5R6 wherein R4, R5 and R6 independently are lower alkyl or cyclo-alkyl and n is an integer of from 2 to 4, with the provision that when X is CH2, Y is OH or NH—(CH2)n—OH, and pharmacologically acceptable salts thereof are described. The compounds are useful as drugs for preventing and/or treating autoimmune diseases.