Outcomes of Adult Acute Myeloid Leukemia Treated With Gemtuzumab-Ozogamicin: Cue To Optimized Chemotherapy Backbone

Background: The optimal approach to combine gemtuzumab-ozogamicin (GO) with various chemotherapy backbones and other newer agents safely remains to be determined.

Materials And Methods: We performed a retrospective analysis of the safety and outcomes of adult patients with newly diagnosed acute myeloid leukemia (AML) treated with GO with intensified versus standard anthracycline doses (daunorubicin dose 90 mg/m vs 60 mg/m) ± FLT3 inhibitors. The χ test and Mann-Whitney U test were used to compare categorical and continuous data. Survival estimates were calculated by Kaplan-Meier method and survival comparisons made using log-rank test.

Results: We report a 97% overall response rate in 34 patients with newly diagnosed AML with a median age of 54 years (19-75 years) treated with GO and standard induction. The 11 patients (100%) receiving GO plus daunorubicin dose 90 mg/m as part of 7 + 3 induction achieved complete response versus 91% (20/22) complete response in the standard daunorubicin dose group (P = NS). No increased toxicity was noted with the higher daunorubicin dose or when GO and 7 + 3 were combined with FLT3 inhibitors in 3 younger patients (<60 years). Two older patients treated with GO+7 + 3 and FLT3i experienced grade 3 or higher cardiotoxicity. We observed a longer estimated event-free survival for patients with newly diagnosed AML in our cohort (median, 24 months; 95% confidence interval, 17.2 to not reached) compared with historical data.

Conclusion: We demonstrate that anthracycline dose intensification with GO may offer higher response rates without increased toxicity in younger patients presenting with de novo AML across European Leukemia Net risk categories.