Effect of induction intensity on survival in patients with acute myeloid leukemia.

e19004 Background: Acute Myeloid Leukemia (AML) has traditionally been treated frontline with intensive induction chemotherapy in patients fit enough for this treatment. The FDA has approved several oral targeted therapies for AML in recent years. The survival impact of these agents vs induction chemotherapy is unknown. Methods: In this single-center, retrospective study, patients diagnosed with AML from 2015-2020 were included if they received treatment with either high intensity chemotherapy (HiC) or lower intensity targeted therapy (LITT). HiC was defined as a regimen containing cytarabine + anthracycline given on a “7+3” based schedule. Patients treated with liposomal cytarabine-daunorubicin were excluded. LITT was defined as venetoclax, gilteritinib, enasidenib, or ivosidenib alone or in combination with a hypomethylating agent. Patients fell into four groups: HiC only, LITT only, HiC followed by LITT, and LITT followed by HiC with assignment censored at transplant. Overall survival (OS) was estimated using Kaplan-Meier method and patients receiving any HiC vs LITT only were compared using log-rank test. Results: A total of 332 patients were included: 177 received HiC only, 116 LITT only, 32 HiC before LITT, and 7 LITT before HiC. Baseline characteristics and OS data are outlined in the table. The any HiC group had a lower median age and more patients with WBC >10 K/µL at diagnosis, as well as more patients receiving allogeneic hematopoietic cell transplant (HCT). OS was superior in the any HiC group vs LITT only group. Receipt of any HiC remained predictive of OS after adjusting for age (HR 0.65, 95% CI 0.44-0.96, p = 0.03); however, was no longer predictive of OS after adjusting for age and receipt of HCT. Conclusions: While HiC was associated with superior OS compared to LITT only treatment in univariable analysis, the survival benefit was no longer apparent after adjusting for age and receipt of HCT. The results suggest that intensity of AML treatment is less impactful on prognosis than ability to receive HCT. Differences in age were likely confounded by clinical trial eligibility and prescribing information specifically affecting patients receiving LITT. In the era of LITT, prospective randomized studies of intensity of AML therapy, particularly in non-favorable risk disease, are imperative to striking a balance between toxicity and cure for patients of all ages.[Table: see text]