P526: REAL-WORLD COMPARISON OF DIFFERENT TREATMENT MODALITIES FOR FAVORABLE RISK ACUTE MYELOID LEUKEMIA: STANDARD DOSE ANTHRACYCLINE VS HIGH DOSE ANTHRACYCLINE VS ADDITION OF GEMTUZUMAB OZOGAMICIN

Abstract

Background: The standard remission induction regimen for medically fit patients with acute myeloid leukemia (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 AML with favorable risk cytogenetics. Gemtuzumab ozogamicin (GO) may improve outcomes in this patient population but is associated with increased toxicities. Aims: We aimed to compare the outcomes of 3 cohorts of newly diagnosed AML with favorable cytogenetics who received induction 7 + 3 induction therapy: 1. Standard dose (45 or 60 mg/m2 daunorubicin) (SD); 2. Higher dose (90 mg/m2 daunorubicin or 12 mg/m2 idarubicin) (HD) of anthracycline, 3. 7 + 3 with fractionated GO. Methods: We performed a multicenter retrospective analysis of medically fit patients ≥ 18 yo with favorable risk AML determined using ELN 2017 guidelines from 2015-2020 treated across 6 US academic institutions. Categorical variables were summarized using means and standard deviations. The former was compared using Fisher’s exact test; the latter was compared using either the Wilcoxon text or the Kruskal-Wallis as appropriate. One way ANOVA test was used to compare continuous variables. Kaplan-Meier curves were generated to provide visual summaries of survival and time-to-event data. Results: Our study included 189 treated patients who met eligibility criteria with a median follow up of 2 years. Patients’ characteristics and outcomes are summarized in Table 1. Sixty-nine (37%) received induction with SD, 100 (53%) received HD, and 20 (11%) received GO. Patients in the SD and HD group were younger (median age 50 and 52 yo, respectively) and the majority (>94%) had de novo AML. The rates of composite complete remission in the SD, HD, and GO groups were 66.7%, 70% and 75%, respectively (p=0.761). RFS and OS were similar between all groups (p=0.4 and 0.3, respectively). The rate and duration of cytopenias at day 40 after induction, major bleeding, infections, admission to the intensive care unit, new onset cardiomyopathy (ejection fraction<50%), liver dysfunction and acute renal injury were similar among all groups. No patients developed veno-occlusive disease. Table 1: - Participant Characteristics and Outcomes by Treatment Regimen GON = 20 HDN = 100 SDN = 69 P-value Age in years (standard deviation) 57.75 (9.32) 49.68 (13.67) 51.55 (13.83) 0.038 de novo AML, N (%) 19 (95.0) 94 (94.0) 65 (94.2) 1.000 Disease status after induction 0.812 CR, N (%) 14 (70.0) 66 (66.0) 40 (58.0) CRi, N (%) 0 (0.0) 2 (2.0) 2 (2.9) Persistent, N (%) 1 (5.0) 4 (4.0) 2 (2.9) Composite CR, N (%) 15 (75.0) 70 (70.0) 46 (66.7) 0.761 Admission to ICU, N (%) 4 (20.0) 17 (17.0) 11 (15.9) 0.969 Infections, N (%) 17 (85.0) 74 (74.0) 62 (89.9) 0.082 Major bleeding, N (%) 3 (15.0) 6 (6.0) 4 (5.8) 0.299 VOD, N (%) 0 (0.0) 0 (0.0) 0 (0.0) Transaminitis, N (%) 4 (20.0) 19 (19.0) 19 (27.5) 0.538 Acute renal injury, N (%) 3 (15.0) 19 (19.0) 15 (21.7) 0.962 Cardiomyopathy, N (%) 4 (20.0) 8 (8.0) 5 (7.2) 0.523 Cytopenias at D40 after induction, N (%) 0 (0.0) 7 (7.0) 6 (8.7) 0.542 Image:Summary/Conclusion: Our analysis demonstrated no differences in RFS and OS in patients with AML treated with either GO, HD or SD. In addition, the rates of complications secondary to chemotherapy were similar among all groups. However, a measurable residual disease analysis is ongoing for further characterization of disease response.