Phase 2 study of epigenetic priming with decitabine followed by cytarabine for acute myeloid leukemia in older patients

Abstract

Acute myeloid leukemia (AML) in older patients has a poor prognosis, low complete remission (CR) rates, and poor overall survival (OS). Preclinical studies have shown synergistic effects of epigenetic priming with hypomethylating agents followed by cytarabine. Based on these data, we hypothesized that an induction regimen using epigenetic priming with decitabine, followed by cytarabine would be effective and safe in older patients with previously untreated AML. Here, we conducted a phase 2 trial in which older patients with previously untreated AML received an induction regimen consisting of 1 or 2 courses of decitabine 20 mg/m² intravenously (IV) for 5 days followed by cytarabine 100 mg/m² continuous IV infusion for 5 days. Forty-four patients (median age 76 years) were enrolled, and CR/CRi was achieved by 26 patients (59% of all patients, 66.7% of evaluable patients). Fourteen of 21 (66.7%) patients with adverse cytogenetics achieved CR including six out of seven evaluable patients with TP53 mutations. The 4- and 8-week mortality rates were 2.3% and 9.1%, respectively, with median OS of 10.7 months. These results suggest epigenetic priming with decitabine followed by cytarabine should be considered as an option for first-line therapy in older patients with AML. This trial was registered at www.clinicaltrials.gov as # NCT01829503.

FIGURE 1

(A) Kaplan–Meier curve for overall survival (OS): All patients (left panel); patients achieving CR/Cri (right panel). (B) Kaplan–Meier curve for overall survival (OS) by cytogenetic risk group. The p-value is from the log-rank test. (C) OS and RFS based on FLT3 and TP53 mutation status. (D) Relapse-free survival based on FLT3 and TP53 mutation status. CR, complete remission; CRi, CR with incomplete count recovery.