The present invention describes methods and compositions for improving the therapeutic efficacy of therapeutically active agents previously limited by suboptimal therapeutic performance by either improving efficacy as monotherapy or reducing side effects. Such methods and compositions are particularly applicable to therapeutically active agents selected from the group consisting of: (i) indirubin； (ii) an analog of indirubin； (iii) a derivative of indirubin or of an analog of indirubin； and (iv) a pharmaceutical composition comprising indirubin, an analog of indirubin, or a derivative of indirubin or of an analog of indirubin, especially meisoindigo.
