[Efficacy and Safety of Decitabine Combined with Modified CAG Regimen in Patients Aged ≥ 70 Years with Newly Diagnosed Acute Myeloid Leukemia]

Abstract

Objective: To evaluate the clinical efficacy and safety of decitabine combined with modified CAG regimen (D-CAG regimen) in patients aged ≥70 years with newly diagnosed acute myeloid leukemia (AML).

Methods: The clinical data of 59 AML patients (≥70 years old) who were newly diagnosed and treated in the Hematology Department of the First Affiliated Hospital of Nanjing Medical University from November 2010 to June 2021 were retrospectively analyzed.

Results: Among the 59 AML patients, 28 were males and 31 were females, with a median age of 74 (70-86) years. The complete remission (CR) rate was 69.4% (34/49), and the median duration of CR was 10.7 (0.6-125.4) months after 2 courses of D-CAG treatment. According to the British Medical Research Council (MRC) classification, there was only one patient in the favorable-risk group, and the CR rate was 71.8% (28/39) in the intermediate-risk group, and 55.6% (5/9) in the adverse-risk group, respectively. There was no statistical difference in the CR rate between the intermediate-risk and adverse-risk group. Referring to ELN 2017 genetic risk classification, CR rate was 88.2% (15/17) in the favorable-risk group, 45.5% (5/11) in the intermediate-risk group, and 66.7% (14/21) in the adverse-risk group. There was no significant difference in CR rate between the favorable-risk and adverse-risk categories, but both were significantly higher than that in the intermediate-risk group (P <0.05). Next-generation sequencing (NGS) analysis showed that 11 gene mutations with a frequency of more than 10%, including TET2 mutation (35.6%), ASXL1 mutation (30.5%), NPM1 mutation (28.8%), FLT3-ITD mutation (27.1%), DNMT3A mutation (22.0%), IDH1 mutation (15.3%), CEBPA single mutation (13.6%), TP53 mutation (13.6%), IDH2 mutation (11.9%), RUNX1 mutation (11.9%), and NRAS mutation (10.2%). There were no statistical differences in mutation frequency of these 11 genes between CR group and non-CR group. Compared with normal karyotypes, patients with complex karyotypes were more likely to develop TP53 mutations (P <0.001), while FLT3-ITD and DNMT3A mutations were more likely to occur in patients with normal karyotypes (P =0.04, P =0.047). The median follow-up, overall survival (OS), and event-free survival (EFS) of all the patients was 11.7 (1.5-128.2) months, 12.3 (1.5-128.2) months, and 8.5 (1.5-128.2) months, respectively. The median OS and EFS of CR patients were 19.8 and 13.3 months, respectively, which were significantly longer than 6.4 and 5.7 months in patients experiencing treatment failure (P < 0.001, P =0.009). In regard to genes with mutation frequency >10%, there were no statistical differences in CR rate, median OS, and median EFS between mutated and wild-type patients by Chi-square test and survival analysis. Univariate analysis showed that age, hemoglobin, lactate dehydrogenase, cytogenetics and CR were factors affecting prognosis, while multivariate analysis showed that only CR failure was an independent adverse prognostic factor for OS. The major adverse reactions to D-CAG regimen were grade 3-4 myelosuppression, pulmonary infection, and fever (infection focus was not identified).

Conclusion: D-CAG regimen is safe and effective in the treatment of AML patients ≥70 years old, and can partially improve the prognosis of elderly and high-risk patients.

Keywords: D-CAG regimen; acute myeloid leukemia; decitabine; efficacy; safety.