Targeting chromosomally unstable tumors with a selective KIF18A inhibitor.

Chromosome instability is a prevalent vulnerability of cancer cells that has yet to be fully exploited therapeutically. To identify genes uniquely essential to chromosomally unstable cells, we mined the Cancer Dependency Map for genes essential in tumor cells with high levels of copy number aberrations. We identify and validate KIF18A, a mitotic kinesin, as a vulnerability of chromosomally unstable cancer cells.

Preclinical Drug Metabolism, Pharmacokinetic, and Pharmacodynamic Profiles of Ivosidenib, an Inhibitor of Mutant Isocitrate Dehydrogenase 1 for Treatment of Isocitrate Dehydrogenase 1-Mutant Malignancies.

Point mutations in isocitrate dehydrogenase 1 () result in conversion of -ketoglutarate to the oncometabolite, d-2-hydroxyglutarate (2-HG). Ivosidenib is a once daily (QD), orally available, potent, mutant isocitrate dehydrogenase 1 (mIDH1) inhibitor approved for the treatment of patients with relapsed or refractory acute myeloid leukemia (AML) and intensive chemotherapy-ineligible newly diagnosed AML, with a susceptible mutation. We characterized the protein binding, metabolism, metabolites, cell permeability, and drug-drug interaction potential of ivosidenib in humans, monkeys, dogs, rats, and/or mice in in vitro experiments.

Hair Cell Mechanotransduction Regulates Spontaneous Activity and Spiral Ganglion Subtype Specification in the Auditory System.

Type I spiral ganglion neurons (SGNs) transmit sound information from cochlear hair cells to the CNS. Using transcriptome analysis of thousands of single neurons, we demonstrate that murine type I SGNs consist of subclasses that are defined by the expression of subsets of transcription factors, cell adhesion molecules, ion channels, and neurotransmitter receptors. Subtype specification is initiated prior to the onset of hearing during the time period when auditory circuits mature.

Discovery of AG-120 (Ivosidenib): A First-in-Class Mutant IDH1 Inhibitor for the Treatment of IDH1 Mutant Cancers.

Somatic point mutations at a key arginine residue (R132) within the active site of the metabolic enzyme isocitrate dehydrogenase 1 (IDH1) confer a novel gain of function in cancer cells, resulting in the production of d-2-hydroxyglutarate (2-HG), an oncometabolite. Elevated 2-HG levels are implicated in epigenetic alterations and impaired cellular differentiation. IDH1 mutations have been described in an array of hematologic malignancies and solid tumors.

AG-348 enhances pyruvate kinase activity in red blood cells from patients with pyruvate kinase deficiency.

Pyruvate kinase (PK) deficiency is a rare genetic disease that causes chronic hemolytic anemia. There are currently no targeted therapies for PK deficiency. Here, we describe the identification and characterization of AG-348, an allosteric activator of PK that is currently in clinical trials for the treatment of PK deficiency.

Isocitrate Dehydrogenase Mutation and (R)-2-Hydroxyglutarate: From Basic Discovery to Therapeutics Development.

The identification of heterozygous mutations in the metabolic enzyme isocitrate dehydrogenase (IDH) in subsets of cancers, including secondary glioblastoma, acute myeloid leukemia, intrahepatic cholangiocarcinoma, and chondrosarcomas, led to intense discovery efforts to delineate the mutations' involvement in carcinogenesis and to develop therapeutics, which we review here. The three IDH isoforms (nicotinamide adenine dinucleotide phosphate-dependent IDH1 and IDH2, and nicotinamide adenine dinucleotide-dependent IDH3) contribute to regulating the circuitry of central metabolism. Several biochemical and genetic observations led to the discovery of the neomorphic production of the oncometabolite (R)-2-hydroxyglutarate (2-HG) by mutant IDH1 and IDH2 (mIDH).

AG-221, a First-in-Class Therapy Targeting Acute Myeloid Leukemia Harboring Oncogenic Mutations.

Somatic gain-of-function mutations in isocitrate dehydrogenases () 1 and 2 are found in multiple hematologic and solid tumors, leading to accumulation of the oncometabolite ()-2-hydroxyglutarate (2HG). 2HG competitively inhibits α-ketoglutarate-dependent dioxygenases, including histone demethylases and methylcytosine dioxygenases of the TET family, causing epigenetic dysregulation and a block in cellular differentiation. studies have provided proof of concept for mutant IDH inhibition as a therapeutic approach.

A mouse model of a human congenital disorder of glycosylation caused by loss of PMM2.

The most common congenital disorder of glycosylation (CDG), phosphomannomutase 2 (PMM2)-CDG, is caused by mutations in PMM2 that limit availability of mannose precursors required for protein N-glycosylation. The disorder has no therapy and there are no models to test new treatments. We generated compound heterozygous mice with the R137H and F115L mutations in Pmm2 that correspond to the most prevalent alleles found in patients with PMM2-CDG.

A small molecule inhibitor of mutant IDH2 rescues cardiomyopathy in a D-2-hydroxyglutaric aciduria type II mouse model.

D-2-hydroxyglutaric aciduria (D2HGA) type II is a rare neurometabolic disorder caused by germline gain-of-function mutations in isocitrate dehydrogenase 2 (IDH2), resulting in accumulation of D-2-hydroxyglutarate (D2HG). Patients exhibit a wide spectrum of symptoms including cardiomyopathy, epilepsy, developmental delay and limited life span. Currently, there are no effective therapeutic interventions.

ALDH2(E487K) mutation increases protein turnover and promotes murine hepatocarcinogenesis.

Mitochondrial aldehyde dehydrogenase 2 (ALDH2) in the liver removes toxic aldehydes including acetaldehyde, an intermediate of ethanol metabolism. Nearly 40% of East Asians inherit an inactive ALDH2*2 variant, which has a lysine-for-glutamate substitution at position 487 (E487K), and show a characteristic alcohol flush reaction after drinking and a higher risk for gastrointestinal cancers. Here we report the characterization of knockin mice in which the ALDH2(E487K) mutation is inserted into the endogenous murine Aldh2 locus.

IDH2 mutation-induced histone and DNA hypermethylation is progressively reversed by small-molecule inhibition.

Mutations of IDH1 and IDH2, which produce the oncometabolite 2-hydroxyglutarate (2HG), have been identified in several tumors, including acute myeloid leukemia. Recent studies have shown that expression of the IDH mutant enzymes results in high levels of 2HG and a block in cellular differentiation that can be reversed with IDH mutant-specific small-molecule inhibitors. To further understand the role of IDH mutations in cancer, we conducted mechanistic studies in the TF-1 IDH2 R140Q erythroleukemia model system and found that IDH2 mutant expression caused both histone and genomic DNA methylation changes that can be reversed when IDH2 mutant activity is inhibited.

Proto-oncogenic role of mutant IDH2 in leukemia initiation and maintenance.

Mutations in the metabolic enzymes isocitrate dehydrogenase-1 (IDH1) and IDH2 that produce the oncometabolite D-2-hydroxyglutarate (2-HG) occur frequently in human acute myeloid leukemia (AML). 2-HG modulates numerous biological pathways implicated in malignant transformation, but the contribution of mutant IDH proteins to maintenance and progression of AML in vivo is currently unknown. To answer this crucial question we have generated transgenic mice that express IDH2(R140Q) in an on/off- and tissue-specific manner using a tetracycline-inducible system.

Targeted inhibition of mutant IDH2 in leukemia cells induces cellular differentiation.

A number of human cancers harbor somatic point mutations in the genes encoding isocitrate dehydrogenases 1 and 2 (IDH1 and IDH2). These mutations alter residues in the enzyme active sites and confer a gain-of-function in cancer cells, resulting in the accumulation and secretion of the oncometabolite (R)-2-hydroxyglutarate (2HG). We developed a small molecule, AGI-6780, that potently and selectively inhibits the tumor-associated mutant IDH2/R140Q.

An inhibitor of mutant IDH1 delays growth and promotes differentiation of glioma cells.

The recent discovery of mutations in metabolic enzymes has rekindled interest in harnessing the altered metabolism of cancer cells for cancer therapy. One potential drug target is isocitrate dehydrogenase 1 (IDH1), which is mutated in multiple human cancers. Here, we examine the role of mutant IDH1 in fully transformed cells with endogenous IDH1 mutations.

Discovery of the First Potent Inhibitors of Mutant IDH1 That Lower Tumor 2-HG in Vivo.

Optimization of a series of R132H IDH1 inhibitors from a high throughput screen led to the first potent molecules that show robust tumor 2-HG inhibition in a xenograft model. Compound 35 shows good potency in the U87 R132H cell based assay and ∼90% tumor 2-HG inhibition in the corresponding mouse xenograft model following BID dosing. The magnitude and duration of tumor 2-HG inhibition correlates with free plasma concentration.

Small molecule activation of PKM2 in cancer cells induces serine auxotrophy.

Proliferating tumor cells use aerobic glycolysis to support their high metabolic demands. Paradoxically, increased glycolysis is often accompanied by expression of the lower activity PKM2 isoform, effectively constraining lower glycolysis. Here, we report the discovery of PKM2 activators with a unique allosteric binding mode.

D-2-hydroxyglutarate produced by mutant IDH1 perturbs collagen maturation and basement membrane function.

Isocitrate dehydrogenase-1 (IDH1) R132 mutations occur in glioma, but their physiological significance is unknown. Here we describe the generation and characterization of brain-specific Idh1 R132H conditional knock-in (KI) mice. Idh1 mutation results in hemorrhage and perinatal lethality.

IDH1(R132H) mutation increases murine haematopoietic progenitors and alters epigenetics.

Mutations in the IDH1 and IDH2 genes encoding isocitrate dehydrogenases are frequently found in human glioblastomas and cytogenetically normal acute myeloid leukaemias (AML). These alterations are gain-of-function mutations in that they drive the synthesis of the ‘oncometabolite’ R-2-hydroxyglutarate (2HG). It remains unclear how IDH1 and IDH2 mutations modify myeloid cell development and promote leukaemogenesis.

Non-invasive detection of 2-hydroxyglutarate and other metabolites in IDH1 mutant glioma patients using magnetic resonance spectroscopy.

Mutations of the isocitrate dehydrogenase 1 and 2 genes (IDH1 and IDH2) are commonly found in primary brain cancers. We previously reported that a novel enzymatic activity of these mutations results in the production of the putative oncometabolite, R(-)-2-hydroxyglutarate (2-HG). Here we investigated the ability of magnetic resonance spectroscopy (MRS) to detect 2-HG production in order to non-invasively identify patients with IDH1 mutant brain tumors.

IDH mutations in glioma and acute myeloid leukemia.

The systematic sequencing of glioblastoma multiforme (GBM) genomes has identified the recurrent mutation of IDH1, a gene encoding NADP(+)-dependent isocitrate dehydrogenase 1 (IDH1) that catalyzes the oxidative decarboxylation of isocitrate yielding alpha-ketoglutarate (alpha-KG). Subsequent studies have confirmed recurrent IDH1 and IDH2 mutations in up to 70% of low-grade glioma and secondary GBM, as well as in 10% of acute myeloid leukemia (AML) cases. The heterozygous somatic mutations at arginine R132 (IDH1) and at R140 or R172 (IDH2) in the enzyme active site confer a gain of function to the enzymes, which can both produce the metabolite 2-hydroxyglutarate.

The common feature of leukemia-associated IDH1 and IDH2 mutations is a neomorphic enzyme activity converting alpha-ketoglutarate to 2-hydroxyglutarate.

The somatic mutations in cytosolic isocitrate dehydrogenase 1 (IDH1) observed in gliomas can lead to the production of 2-hydroxyglutarate (2HG). Here, we report that tumor 2HG is elevated in a high percentage of patients with cytogenetically normal acute myeloid leukemia (AML). Surprisingly, less than half of cases with elevated 2HG possessed IDH1 mutations.

Cancer-associated metabolite 2-hydroxyglutarate accumulates in acute myelogenous leukemia with isocitrate dehydrogenase 1 and 2 mutations.

Mutations in isocitrate dehydrogenase 1 and 2 (IDH1/2), are present in most gliomas and secondary glioblastomas, but are rare in other neoplasms. IDH1/2 mutations are heterozygous, and affect a single arginine residue. Recently, IDH1 mutations were identified in 8% of acute myelogenous leukemia (AML) patients.