AML-225: Outcome with Intensive Chemotherapy vs Hypomethylating Agent-Based Induction Strategies in Patients Older Than 70 Years with Newly Diagnosed, Favorable-Risk Acute Myeloid Leukemia

Abstract

<h3>Context:</h3> Real-world evidence is lacking regarding the effectiveness of intensive and non-intensive induction strategies in elderly patients with favorable-risk acute myeloid leukemia (AML). <h3>Objectives:</h3> To estimate the rates of complete remission (CR), CR+ CR with incomplete count recovery (CRi), and overall survival (OS) in patients receiving intensive chemotherapy (IC) and hypomethylating agent (HMA)-based induction regimens. <h3>Design:</h3> In this retrospective study, clinical and genomic data were collected by review of records of eligible patients treated at Moffitt Cancer Center. Statistical analyses were performed using SPSS. <h3>Patients:</h3> Elderly (age > 70 years) patients with newly diagnosed, favorable-risk (ELN 2017) AML. <h3>Main Outcomes Measures:</h3> CR, CR+ CRi, OS. <h3>Results:</h3> Out of total 53 patients, 36 (68%) received IC, and 17 (32%) received HMA-based induction regimen. Median age at diagnosis was 74 years (range 70–85). Core binding factor (CBF) abnormalities were detected in 47% patients; 28% had secondary AML. Median blast count was significantly higher in patients receiving IC <i>vs</i> HMA (58% <i>vs</i> 32%, p=0.01). Predominant induction regimen was "7+3" (86%) in the IC group and azacytidine alone (n=11) in HMA cohort. Rate of composite CR (CR+ CRi) was significantly better at 69% (50% CR) in the IC group, compared to 35% (24% CR) with HMA (p=0.01). Six patients on IC and 1 on HMA had early (<30 d) induction-related mortality. Both groups had comparable relapse rates (overall 34%). Median OS was 24.7 months in IC <i>vs</i> 17.5 months in the HMA group, trending toward statistical significance (p=0.058). Overall, 23% patients in the IC group were alive at 5 years, compared to 7% with HMA. In patients with CBF-AML (n=25), median OS was not reached for IC <i>vs</i> 23 months with HMA (p= 0.076); CBF-AML was an independent predictor of survival in the study population. Six patients (3 post-relapse) from the IC group underwent allogeneic stem cell transplant. <h3>Conclusions:</h3> Elderly favorable-risk AML patients had a significantly better composite CR rate on induction treatment with IC than with HMA, with a trend toward improved OS with IC-based induction. A multicenter study with a larger sample size is ongoing to address this question further.