Comparison of different treatment modalities for favorable risk acute myeloid leukemia: Standard-dose anthracycline versus high-dose anthracycline versus addition of gemtuzumab ozogamicin.

Abstract

e19016 Background: The standard remission induction regimen for medically fit patients with AML consists of a backbone of cytarabine & an anthracycline (“7+3” therapy). However, the choice & dose of the anthracycline varies between institutions & practitioner preference, particularly in patients with favorable risk cytogenetics. Gemtuzumab ozogamicin (GO) may improve outcomes in this patient population but is associated with increased toxicities. Methods: We performed a retrospective analysis on medically fit patients ≥ 18 yo with favorable risk AML from 2015-2020 treated with 7+3 at the University of Virginia. Patients were stratified based on standard dose (45 or 60 mg/m2 daunorubicin) (SD) vs higher dose (90 mg/m2 daunorubicin or 12 mg/m2 idarubicin) (HD) of anthracycline vs the addition of GO. Measures included rates of remission, EFS, RFS, and OS as well as rates of treatment-related complications. Results: In total, 58 patients were identified, of which 33 received induction with SD, 19 received HD, & 6 received GO. The majority (75%) of patients were < 60 years old & 93% had de novo AML. The rates of complete remission in the SD, HD & GO groups were 90.9%, 89.5% & 100%, respectively (p = 0.57). EFS at 2-years was 43.9%, 36.7%, & 66.7%, respectively (p = 0.85). RFS at 2-years was 53.0%, 39.0%, & 100%, respectively (p = 0.18). OS at 2-years was similar between all groups (58.9%, 56.9%, & 66.7%, p = 0.92). The rate & duration of cytopenias after induction were similar among all groups (median duration 29 days), however cytopenias were more common in the GO group following consolidation. The rates of major bleeding, admission to the intensive care unit (ICU), and new onset cardiomyopathy (EF < 50%) were higher in the GO group (major bleeding: 0% in SD, 5.3% in HD, 33.3% in GO; ICU admission: 12.1% in SD, 21.1% in HD, 33.3% in GO; cardiomyopathy: 12.1% in SD, 26.3% in HD, 33.3% in GO). The rate of infection, liver dysfunction, & acute renal injury were similar among all groups. No patients developed veno-occlusive disease. Conclusions: Patients receiving GO had a trend toward improved EFS & RFS, however with a similar OS at the expense of higher rates of cytopenias, major bleeding, ICU admission, & cardiotoxicity. Patients receiving HD had a trend toward worse outcomes than those who received SD. A major limitation of our study is the small sample size & single institution experience, however multi-institutional analysis is ongoing for further investigation.[Table: see text]