Characteristics and outcomes of patients diagnosed with DNMT3A mutated acute myeloblastic leukemia.
Authors: Rivera Daniel , Kantarjian Hagop M. , Kadia Tapan M. , Daver Naval Guastad , Dinardo Courtney Denton , Short Nicholas James , Yilmaz Musa , Jabbour Elias , Garcia-Manero Guillermo , Konopleva Marina , Borthakur Gautam , Ravandi Farhad 
Published: June 2021

e19018

Background: Advances in molecular profiling have identified recurring gene mutations in acute myeloid leukemia (AML) that have independent prognostic significance with several being targets for the development of new small molecule inhibitors. DNMT3A mutations have been reported in up to 34% of patients with AML. Mutations of this gene are associated with silencing of tumor suppressor genes, thereby leading to leukemogenesis. Several prior reports have suggested an association with worse outcomes. Methods: We retrospectively reviewed records of 258 patients with ND AML with DNMT3A mutations who presented to our institution from 2002 to 2020. We analyzed their clinical and laboratory characteristics. We estimated their overall survival (OS) and disease-free survival (DFS) through the Kaplan-Meier method. P-value was 2-tailed, ≤ 0.05 was considered statistically significant with a confidence interval of 95%. Univariate and multivariate analyses were also applied. Results: Our cohort had a median age of 66 years, 56% were female. The majority of the patients (77%) had de novo AML and the M0 FAB subtype was predominantly observed in 70%. Diploid karyotype was detected in 60% while complex karyotype in 14% of patients. DNMT3A was most frequently mutated at codon 882 (64%). NPM1 was the most frequent concomitant mutation followed by FLT3-ITD and IDH2. Age > 65 years (p = 0.001) and presence of concomitant TP53 mutation (p < 0.001) were associated with worse survival and concomitant NPM1 was associated with a 40% reduction of death, p = 0.003. Secondary AML and concurrent TP53 mutation were associated with a higher risk of relapse, (p < 0.001 for both). Intensive chemotherapy (ICT) was administered to 82 patients of which 68 achieved a complete response or CR with incomplete count recovery (CRi). Nineteen patients were treated with Cladribine plus low dose Ara-C (Clad-LDAC) and CR or CRi was achieved in 16 patients. Eleven treated with Clad-LDAC-Ven and all achieved CR/CRi. Hypomethylating agents (HMA) were given to 22 patients of which 10 achieved CR/CRi. Twenty-five received HMA-Ven, of these, CR/CRi was achieved in 20 patients (p = 0.02). There was an 80% and 90% reduction of death with ICT, p < 0.001 and Clad-LDAC-Ven, p = 0.04 respectively. Moreover, the risk for relapse was reduced by 70% and 90% with ICT and Clad-LDAC-Ven respectively. Ninety-seven patients were treated with immunotherapy, FLT3 inhibitors, and IDH inhibitors, which were not included in this analysis. Conclusions: DNMT3A mutations have an independent prognostic impact in patients diagnosed with AML. Among these patients, older age, secondary AML, a concomitant mutation in TP53 showed a significant negative impact in terms of OS and DFS. Concomitant mutations in NPM1 and IDH2 were associated with better outcomes. Treatment with intensive chemotherapy or clad-LDAC-Ven was associated with the highest response rates.