Disclosed are methods and compositions for treating ore preventing a STAT5-mediated medical condition, e.g., rheumatoidarthritis, in a subject by administering to the subject a therapeuticallyeffective amount of a compound, the compound being aSTAT5 inhibitor, or a pharmaceutically acceptable salt of the STAT5 inhibitor,or a solvate of the STAT5 inhibitor, or a prodrug of theSTAT5 inhibitor. In one example, the compound used in the methods andcompositions is pimozide. In another example, the compoundused in the methods and compositions is nicotinohydrazide.
