Addition of gemtuzumab ozogamicin (GO) to induction chemotherapy improves outcomes in older patients with acute myeloid leukemia (AML) but it is uncertain whether a fractionated schedule provides additional benefit to a single dose. We randomised 852 older adults (median age 68yrs) with AML/high risk myelodysplasia to GO on day 1 (GO1), or on days 1 and 4 (GO2) of course-1 induction. Median follow-up was 50.2 months. While complete remission rates post course 1 did not significantly …