Abstract C099: Establishment and characterization of an NUP98-KDM5A-driven AML XPDX model

Abstract

Abstract Background: Acute myeloid leukemia (AML) with NUP98 fusions is associated with poor prognosis in adults and especially children. Pediatric AML is a rare and heterogeneous disease characterized by a high prevalence of gene fusions as driver mutations, including the NUP98-KDM5A fusion found in a particular subgroup of patients with complex karyotypes. To better understand this subtype of AML, we established and characterized a XPDX model designated ST1653 representing NUP98-KDM5A-driven disease from a previously treated AML patient. We performed DNA and RNA-based sequencing of the model. Further we evaluated in vivo sensitivity towards cytarabine and inhibitors targeting the JAK and CDK6 pathways, which have been shown to be important in NUP98-KDM5A-driven AML. Methods: ST1653 was established from a bone marrow aspirate collected from a 63-year-old Caucasian male who had AML recurrence following high dose cytarabine. The sample was injected subcutaneously into a triple-deficient mouse and the P0 model passaged after seventy days into CB-17 SCID and athymic nude mice and further developed until stable. WES and RNAseq were then performed. For in vivo studies, ST1653 was evaluated against cytarabine and the JAK inhibitors ruxolitinib, baricitinib and tofacitinib and the CDK4/6 inhibitors palbociclib, abemaciclib and ribociclib. Endpoints in all studies included tumor volume and time from treatment initiation with %T/C values and tumor regression reported at study completion; a T/C of ≤ 20% versus control was considered sensitive. Tumor regression (%T/C<0%) versus Day 0 tumor volume was also reported. Results: Growth of the ST1653 AML XPDX model was similar in CB-17 SCID or athymic nude mice with a median time to endpoint of forty-five days, although the take rate in the SCID strain was superior. Sequencing identified the presence of the NUP98-KDM5A fusion and chimeric protein expression was confirmed. In vivo, ST1653 was insensitive to cytarabine and the JAK inhibitors but demonstrated limited sensitivity to CDK4/6i treatment. Conclusion: We have established and characterized a XPDX model of NUP98-KDM5A-driven AML including sequencing and in vivo evaluation. This model is an important tool for developing novel therapies to this high-risk leukemia subtype. Citation Format: Armando Diaz III, Alyssa Simonson, Johnnie Flores, Joseph Holahan, Kyriakos P Papadopoulos, Jim Lund, Drew Rasco, Amita Patnaik, Michael J Wick. Establishment and characterization of an NUP98-KDM5A-driven AML XPDX model [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr C099.