Methods are provided of treating renal cancer by administration of certain3,3',4,4'-tetrahydroxy-2,2'-bipyridine-N,N'-dioxide compounds,whereinR1, R2, R3 and R4 are independently hydrogen, amino, mercapto, carboxy,phosphate, halo,C1-C6 alkyl, C1-C6 alkenyl, C1-C6 alkynyl, C1-C6 alkanol, C1-C6 alkenol, C1-C6alkoxy orC1-C6 alkenoxy, each of C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C1-C6alkanol, C2-C6alkenol, C1-C6 alkoxy and C2-C6 alkenoxy, may be further substituted withgroups which areamino, mercapto, carboxy, phosphate or halo,especially 3,3',4,4'-tetrahydroxy-2,2'-bipyridine-N,N'-dioxide (Orellanine),using particularadministration protocols and dosing regimens, as well as pharmaceuticalcompositionssuitable for use in the treatment methods that are provided.
