Undesired effects of dosing interruption. The figure shows the undesired effects of dosing interruption followed by dose reduction in a patient responding to ESA therapy and reaching an Hb ≥ 12 g/dL (starting from a baseline Hb of 8.5 g/dL). The lower line marks the IWG 2006 response (8.5-10 g/dL) and upper line the general Hb cutoff for dose interruption in many clinical trials (12 g/dL).