Biology and Clinical Implications of Complex Landscape of Cooperating Events in FLT3-ITD Acute Myeloid Leukemia

Autor: E. Anders Kolb, Quy Le, Xiaotu Ma, Jenny L. Smith, Richard Aplenc, Todd A. Alonzo, Tiffany A. Hylkema, Jessica A. Pollard, Katherine Tarlock, Leila Robinson, Yi-Cheng Wang, Amanda R. Leonti, Robert B. Gerbing, Rhonda E. Ries, Soheil Meshinchi
Rok vydání: 2021
Předmět:
Zdroj: Blood. 138:3454-3454
ISSN: 1528-0020
0006-4971
DOI: 10.1182/blood-2021-153703
Popis: FLT3-ITD mutations are among the most common somatic mutations in acute myeloid leukemia (AML) and are important in prognostic determination as well as therapeutic allocation. Recent studies have demonstrated improved outcomes with the addition of FLT3 inhibitors and for some patients hematopoietic stem cell transplant (HSCT) in first remission (CR1). We have previously demonstrated that the outcome of FLT3-ITD patients can be quite heterogeneous based on the co-occurrence of a few specific risk stratifying mutations, including NPM1 and NUP98-NSD1. We sought to interrogate the complex landscape of cooperating events with FLT3-ITD AML and potential impacts on outcome in the context of contemporary therapies, including the FLT3 inhibitor sorafenib. Of the 1296 children and young adult patients with de novo AML enrolled on COG AAML1031, 229 had FLT3-ITD mutations and were included in this study. Patients with high allelic ratio (HAR; >0.4) FLT3-ITD were allocated to Arm C, received sorafenib in combination with chemotherapy and received HSCT in CR1. Those with low allelic ratio (LAR; £ 0.4) FLT3-ITD were treated on Arm A/B and received chemotherapy, no sorafenib, and did not receive HSCT in CR1 unless they had evidence of residual disease following induction I (MRD³ 0.1%) or a high-risk cytogenetic feature. FLT3-ITD status and allelic ratio were determined by PCR and all samples also underwent karyotyping, FISH, and next generation sequencing in 195 (85%) of cases for determination of comprehensive co-occurring mutational profile. Among the 229 FLT3-ITD positive patients, allelic ratio ranged from Comprehensive sequencing demonstrated the FLT3-ITD samples identified co-occurring genetic mutations or cytogenetic abnormalities in the majority of cases. Although KMT2A-PTD is rarely reported in pediatric compared to adult AML, we found it was enriched in FLT3-ITD patients and this cohort experienced favorable outcomes when treated with transplant and sorafenib. Patients with dual FLT3-ITD/trisomy 8 had suboptimal outcomes similar to other poor risk co-occurring lesions and comparable regardless of AR or treatment arm. While there was some overlap with WT1 mutations in this cohort, further investigation into prognostic impact of this cooperating event is warranted. The prognostic implications FLT3-ITD mutations vary and we provide further data that the comprehensive cooperating mutational profile is critical to understanding the prognostic implications in specific patients, and may also impact response to FLT3 inhibitor therapy. Figure 1 Figure 1. Disclosures Hylkema: Moderna: Current equity holder in publicly-traded company; Quest Diagnostics Inc: Current equity holder in publicly-traded company. Pollard: Kura Oncology: Membership on an entity's Board of Directors or advisory committees; Syndax: Membership on an entity's Board of Directors or advisory committees.
Databáze: OpenAIRE