Overexpression of annexin A5 might guide the gemtuzumab ozogamicin treatment choice in patients with pediatric acute myeloid leukemia

Abstract

Background: Acute myeloid leukemia (AML) is a common hematological malignancy. Gemtuzumab ozogamicin (GO), a humanized anti-CD33 antibody conjugated with the potent anti-tumor antibiotic calicheamicin, represents a promising targeted therapy for AML. Annexin A5 (ANXA5) is a proposed marker for the clinical prognosis of AML to guide treatment choice.

Methods: In total, 253 patients with pediatric AML were enrolled and divided into two treatment groups: conventional chemotherapy alone and conventional chemotherapy in combination with GO. Univariate, multivariate, and Kaplan-Meier survival analyses were conducted to assess risk factors and clinical outcomes, and to estimate hazard ratios (HRs) and their 95% confidence interval. The level of statistical significance was set at p < 0.05.

Results: In the GO treatment group, high ANXA5 expression was considered a favorable prognostic factor for overall survival (OS) and event-free survival (EFS). Multivariate analysis showed that high ANXA5 expression was an independent favorable factor for OS (HR = 0.629, p = 0.084) and EFS (HR = 0.544, p = 0.024) distinct from the curative effect of GO treatment. When all patients were again divided into two groups, this time based on the median expression of ANXA5, patients undergoing chemotherapy combined with GO had significantly better OS (p = 0.0012) and EFS (p = 0.0003) in the ANXA5 high-expression group. Gene set enrichment analysis identified a relevant series of pathways associated with glutathione metabolism, leukocyte transendothelial migration, and hematopoietic cell lineage.

Conclusion: The expression level of ANXA5 can help optimize the treatment regimen for individual patients, and patients with overexpression of ANXA5 may circumvent poor outcomes from chemotherapy combined with GO.

Keywords: ANXA5; acute myeloid leukemia; chemotherapy; gemtuzumab ozogamicin; prognosis.

Figure 1.

Kaplan–Meier curves of survival in pediatric AML patients with respect to ANXA5 expression. (a, b) Effect of ANXA5 expression on OS and EFS in the no-GO treatment group (n = 95). (c, d) Patients with high ANXA5 expression had significantly prolonged OS and EFS in the GO treatment group (n = 158). AML, acute myeloid leukemia; EFS, event-free survival; GO, gemtuzumab ozogamicin; OS, overall survival.

Figure 2.

Forest plot of HR for OS according to prognostic factors with all patients with AML. Multivariate analyses of age, sex, CNS disease, DEK-NUP214, RUNX1-RUNX1T1, CBFB-MYH11, FLT3-ITD, complex karyotype, MLL, NPM1 mutation, CEBPA mutation, WT1 mutation, GO treatment and ANXA5 expression group for OS in all patients. The black squares on the transverse lines represent the HR, and the gray transverse lines represent 95% CI. AML, acute myeloid leukemia; CI, confidence interval; CNS, central nervous system; GO, gemtuzumab ozogamicin; HR, hazard ratio; OS, overall survival. *p < 0.05 and **p < 0.01.

Figure 3.

Nomogram for the prediction of OS at 1-, 3- and 5-years according to the clinical–biological prognostic index in patients with pediatric AML. By adding up the points assigned to each predictive variable, the total score on the bottom scale shows the probability of survival. AML, acute myeloid leukemia; OS, overall survival.

Figure 4.

GO treatment circumvents the unfavorable outcomes of high ANXA5 expression in pediatric AML patients. A total of 253 patients were divided into two groups based on the median expression levels of ANXA5. (a, b) Kaplan–Meier curves of OS and EFS in patients with GO treatment (n = 80) and without GO treatment (n = 46) in the high-ANXA5-expression group. (c, d) Kaplan–Meier curves of OS and EFS in patients with GO treatment (n = 78) and without GO treatment (n = 49) in the low-ANXA5-expression group. AML, acute myeloid leukemia; EFS, event-free survival; GO, gemtuzumab ozogamicin; OS, overall survival.

Figure 5.

Analysis of ANXA5 gene expression. (a) The network for ANXA5 and the most frequently altered neighbor genes, analyzed by STRING. (b) Immune-related genes coexpressed of heat map with ANXA5 in pediatric AML. (c) The expression of ANXA5 in tumor cell lines, analyzed by CCLE. AML, acute myeloid leukemia; CCLE, the Cancer Cell Line Encyclopedia; STRING, Search Tool for the Retrieval of Interacting Genes.

Figure 6.

Gene ontology terms of biological processes, cellular component, and molecular function in the ANXA5 associated expression profile with pediatric AML. The size of each dot represents the count of genes, the color represents the adjusted p-value. AML, acute myeloid leukemia.

Figure 7.

GSEA results showing differential enrichment of genes related to glutathione metabolism, leukocyte transendothelial migration, chemokine signaling pathway, NOTCH signaling pathway, Toll-like receptor signaling pathway, hematopoietic cell lineage, VEGF signaling pathway, and B-cell receptor signaling pathway in pediatric AML with high ANXA5 expression. AML, acute myeloid leukemia; GSEA, gene set enrichment analysis; VEGF, vascular endothelial growth factor.