Project description:Menin inhibitors have demonstrated profound preclinical activity in MLL1-rearranged and NPM1 mutated AML and in this context, ziftomenib is a novel compound currently assessed in a clinical phase I/II trials. We assessed preclinical effects of ziftomenib and demonstrate profound synergy in combination with compounds targeting chromatin regulation and apoptosis including the BCL2 inhibitor venetoclax which was validated in primary AML samples and an MLL-r and NPM1 mutated AML xenograft model.
Project description:The interaction of Menin (MEN1) and MLL (MLL1, KMT2A) is a dependency and potential therapeutic opportunity against NPM1 mutant (NPM1mut) and MLL-rearranged (MLL-r) leukemias. Concomitant activating driver mutations in the gene encoding the tyrosine kinase FLT3 occur in both leukemias and are particularly common in the NPM1mut subtype. Transcriptional profiling upon pharmacological inhibition of the Menin-MLL complex revealed specific changes in gene expression with downregulation of the MEIS1 transcription factor and its transcriptional target gene FLT3 being most pronounced. Combining Menin-MLL inhibition with specific small molecule kinase inhibitors of FLT3 phosphorylation resulted in a significantly superior reduction of phosphorylated FLT3 and transcriptional suppression of genes downstream to FLT3 signaling. The drug combination induced synergistic inhibition of proliferation as well as enhanced apoptosis and differentiation compared to single-drug treatment in models of human and murine NPM1mut and MLL-r leukemias harboring an FLT3 mutation. Primary AML cells harvested from patients with NPM1mut FLT3mut AML showed significantly better responses to combined Menin and FLT3 inhibition than to single-drug or vehicle control treatment, while AML cells with wildtype NPM1, MLL, and FLT3 were not affected by any of the two drugs. In vivo treatment of leukemic animals with MLL-r FLT3mut leukemia reduced leukemia burden significantly and prolonged survival compared to the single-drug and vehicle control groups. Our data suggest that combined Menin-MLL and FLT3 inhibition represents a novel and promising therapeutic strategy for patients with NPM1mut or MLL-r leukemia and concurrent FLT3 mutation.
Project description:Genome-scale functional genetic screening was utilized to identify resistance mechanisms and synthetic lethal interactions during small molecule targeting of MENIN and DOT1L in MLL1-rearranged AML. Chromatin regulatory complexes are found to modulate the therapeutic response to these inhibitors, and IKZF1/IKAROS is identified as an essential transcriptional regulator that supports leukemia gene expression through extensive chromatin co-occupancy with MENIN and the transcription factor MEIS1. Furthermore, we show that combined IKAROS degradation with imide drugs and MENIN inhibition using VTP-50469 leads to synergistic anti-leukemic effects through rapid induction of apoptotic cell death both in vitro and in vivo. This study uncovers a previously underappreciated role for IKAROS in AML and cooperativity among IKAROS, MLL1/MENIN and MEIS1 in maintaining leukemogenic transcription.
Project description:Genome-scale functional genetic screening was utilized to identify resistance mechanisms and synthetic lethal interactions during small molecule targeting of MENIN and DOT1L in MLL1-rearranged AML. Chromatin regulatory complexes are found to modulate the therapeutic response to these inhibitors, and IKZF1/IKAROS is identified as an essential transcriptional regulator that supports leukemia gene expression through extensive chromatin co-occupancy with MENIN and the transcription factor MEIS1. Furthermore, we show that combined IKAROS degradation with imide drugs and MENIN inhibition using VTP-50469 leads to synergistic anti-leukemic effects through rapid induction of apoptotic cell death both in vitro and in vivo. This study uncovers a previously underappreciated role for IKAROS in AML and cooperativity among IKAROS, MLL1/MENIN and MEIS1 in maintaining leukemogenic transcription.
Project description:Genome-scale functional genetic screening was utilized to identify resistance mechanisms and synthetic lethal interactions during small molecule targeting of MENIN and DOT1L in MLL1-rearranged AML. Chromatin regulatory complexes are found to modulate the therapeutic response to these inhibitors, and IKZF1/IKAROS is identified as an essential transcriptional regulator that supports leukemia gene expression through extensive chromatin co-occupancy with MENIN and the transcription factor MEIS1. Furthermore, we show that combined IKAROS degradation with imide drugs and MENIN inhibition using VTP-50469 leads to synergistic anti-leukemic effects through rapid induction of apoptotic cell death both in vitro and in vivo. This study uncovers a previously underappreciated role for IKAROS in AML and cooperativity among IKAROS, MLL1/MENIN and MEIS1 in maintaining leukemogenic transcription.
Project description:Genome-scale functional genetic screening was utilized to identify resistance mechanisms and synthetic lethal interactions during small molecule targeting of MENIN and DOT1L in MLL1-rearranged AML. Chromatin regulatory complexes are found to modulate the therapeutic response to these inhibitors, and IKZF1/IKAROS is identified as an essential transcriptional regulator that supports leukemia gene expression through extensive chromatin co-occupancy with MENIN and the transcription factor MEIS1. Furthermore, we show that combined IKAROS degradation with imide drugs and MENIN inhibition using VTP-50469 leads to synergistic anti-leukemic effects through rapid induction of apoptotic cell death both in vitro and in vivo. This study uncovers a previously underappreciated role for IKAROS in AML and cooperativity among IKAROS, MLL1/MENIN and MEIS1 in maintaining leukemogenic transcription.
Project description:Genome-scale functional genetic screening was utilized to identify resistance mechanisms and synthetic lethal interactions during small molecule targeting of MENIN and DOT1L in MLL1-rearranged AML. Chromatin regulatory complexes are found to modulate the therapeutic response to these inhibitors, and IKZF1/IKAROS is identified as an essential transcriptional regulator that supports leukemia gene expression through extensive chromatin co-occupancy with MENIN and the transcription factor MEIS1. Furthermore, we show that combined IKAROS degradation with imide drugs and MENIN inhibition using VTP-50469 leads to synergistic anti-leukemic effects through rapid induction of apoptotic cell death both in vitro and in vivo. This study uncovers a previously underappreciated role for IKAROS in AML and cooperativity among IKAROS, MLL1/MENIN and MEIS1 in maintaining leukemogenic transcription.
Project description:Genome-scale functional genetic screening was utilized to identify resistance mechanisms and synthetic lethal interactions during small molecule targeting of MENIN and DOT1L in MLL1-rearranged AML. Chromatin regulatory complexes are found to modulate the therapeutic response to these inhibitors, and IKZF1/IKAROS is identified as an essential transcriptional regulator that supports leukemia gene expression through extensive chromatin co-occupancy with MENIN and the transcription factor MEIS1. Furthermore, we show that combined IKAROS degradation with imide drugs and MENIN inhibition using VTP-50469 leads to synergistic anti-leukemic effects through rapid induction of apoptotic cell death both in vitro and in vivo. This study uncovers a previously underappreciated role for IKAROS in AML and cooperativity among IKAROS, MLL1/MENIN and MEIS1 in maintaining leukemogenic transcription.
Project description:Genome-scale functional genetic screening was utilized to identify resistance mechanisms and synthetic lethal interactions during small molecule targeting of MENIN and DOT1L in MLL1-rearranged AML. Chromatin regulatory complexes are found to modulate the therapeutic response to these inhibitors, and IKZF1/IKAROS is identified as an essential transcriptional regulator that supports leukemia gene expression through extensive chromatin co-occupancy with MENIN and the transcription factor MEIS1. Furthermore, we show that combined IKAROS degradation with imide drugs and MENIN inhibition using VTP-50469 leads to synergistic anti-leukemic effects through rapid induction of apoptotic cell death both in vitro and in vivo. This study uncovers a previously underappreciated role for IKAROS in AML and cooperativity among IKAROS, MLL1/MENIN and MEIS1 in maintaining leukemogenic transcription.