Results of Rt-Q-PCR studies from 3 patients during the therapy with GO. The fusion gene copy number was normalized to the control gene ABL, and the results were expressed in PML/RARα copy numbers per 104 copies of ABL. The arrows indicate the time of GO administrations. (A) Patient no. 1 received 3 doses and remained in sustained MR for 31 months. (B) Patient no. 4 experienced a relapse and was treated again with GO; this patient obtained a second MR after 4 additional GO doses. (C) Patient no. 11 achieved MR after the first GO dose and received no further therapy owing to grade 3 hepatic toxicity.