RESUMO
Point mutations in isocitrate dehydrogenase 1 (IDH1) result in conversion of α-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 IDH1 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. In vivo pharmacokinetic (PK) profiling and assessment of drug distribution and excretion was undertaken in rats, dogs, and monkeys administered single-dose ivosidenib. The PK/pharmacodynamic (PD) relationship between ivosidenib and 2-HG was analyzed in an mIDH1 xenograft mouse model. Ivosidenib was well absorbed, showed low clearance, and moderate to long terminal half-life (5.3-18.5 hours) in rats, dogs, and monkeys. Brain to plasma exposure ratio was low (2.3%), plasma protein binding was high, and oxidative metabolism was the major elimination pathway. Ivosidenib had high cell permeability and was identified as a substrate for P-glycoprotein. There was moderate induction of cytochrome P450 (P450) enzymes CYP3A4 and CYP2B6 but minimal P450 inhibition or autoinduction. Tumor 2-HG reduction appeared to be dose- and drug-exposure-dependent. Ivosidenib showed a favorable PK profile in several animal species, along with a clear PK/PD relationship demonstrating 2-HG inhibition that translated well to patients with AML. SIGNIFICANCE STATEMENT: Ivosidenib is a mutant IDH1 (mIDH1) inhibitor approved for the treatment of certain patients with mIDH1 acute myeloid leukemia. In Sprague-Dawley rats, beagle dogs, and cynomolgus monkeys, ivosidenib demonstrated a favorable pharmacokinetic profile, and in female BALB/c mice showed clear dose- and exposure-dependent inhibition of the oncometabolite, d-2-hydroxyglutarate, which is present at abnormal levels in mIDH1 tumors. These findings led to the further development of ivosidenib and are consistent with data from patients with mIDH1 cancers and healthy participants.
Assuntos
Glicina/análogos & derivados , Isocitrato Desidrogenase/metabolismo , Leucemia Mieloide Aguda , Piridinas/farmacocinética , Animais , Antineoplásicos/farmacocinética , Sistema Enzimático do Citocromo P-450/metabolismo , Cães , Relação Dose-Resposta a Droga , Vias de Eliminação de Fármacos , Interações Medicamentosas , Glutaratos/metabolismo , Glicina/farmacocinética , Haplorrinos , Humanos , Isocitrato Desidrogenase/antagonistas & inibidores , Isocitrato Desidrogenase/genética , Ácidos Cetoglutáricos/metabolismo , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/genética , Taxa de Depuração Metabólica , Camundongos , Mutação Puntual , Ligação Proteica , Ratos , Ensaios Antitumorais Modelo de Xenoenxerto/métodosRESUMO
Small cell lung cancer (SCLC) is a particularly aggressive subset of lung cancer, and identification of new therapeutic options is of significant interest. We recently reported that SCLC cell lines display a specific vulnerability to inhibition of squalene epoxidase (SQLE), an enzyme in the cholesterol biosynthetic pathway that catalyzes the conversion of squalene to 2,3-oxidosqualene. Since it has been reported that SQLE inhibition can result in dermatitis in dogs, we conducted a series of experiments to determine if SQLE inhibitors would be tolerated at exposures predicted to drive maximal efficacy in SCLC tumors. Detailed profiling of the SQLE inhibitor NB-598 showed that dogs did not tolerate predicted efficacious exposures, with dose-limiting toxicity due to gastrointestinal clinical observations, although skin toxicities were also observed. To extend these studies, two SQLE inhibitors, NB-598 and Cmpd-4â³, and their structurally inactive analogs, NB-598.ia and Cmpd-4â³.ia, were profiled in monkeys. While both active SQLE inhibitors resulted in dose-limiting gastrointestinal toxicity, the structurally similar inactive analogs did not. Collectively, our data demonstrate that significant toxicities arise at exposures well below the predicted levels needed for anti-tumor activity. The on-target nature of the toxicities identified is likely to limit the potential therapeutic utility of SQLE inhibition for the treatment of SCLC.
Assuntos
Inibidores Enzimáticos/sangue , Inibidores Enzimáticos/toxicidade , Esqualeno Mono-Oxigenase/antagonistas & inibidores , Esqualeno Mono-Oxigenase/sangue , Animais , Cães , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos/métodos , Macaca fascicularis , Masculino , Pele/efeitos dos fármacos , Pele/enzimologia , Pele/patologiaRESUMO
Mutations in isocitrate dehydrogenase 1 (IDH1) and IDH2 are among the most common genetic alterations in intrahepatic cholangiocarcinoma (IHCC), a deadly liver cancer. Mutant IDH proteins in IHCC and other malignancies acquire an abnormal enzymatic activity allowing them to convert α-ketoglutarate (αKG) to 2-hydroxyglutarate (2HG), which inhibits the activity of multiple αKG-dependent dioxygenases, and results in alterations in cell differentiation, survival, and extracellular matrix maturation. However, the molecular pathways by which IDH mutations lead to tumour formation remain unclear. Here we show that mutant IDH blocks liver progenitor cells from undergoing hepatocyte differentiation through the production of 2HG and suppression of HNF-4α, a master regulator of hepatocyte identity and quiescence. Correspondingly, genetically engineered mouse models expressing mutant IDH in the adult liver show an aberrant response to hepatic injury, characterized by HNF-4α silencing, impaired hepatocyte differentiation, and markedly elevated levels of cell proliferation. Moreover, IDH and Kras mutations, genetic alterations that co-exist in a subset of human IHCCs, cooperate to drive the expansion of liver progenitor cells, development of premalignant biliary lesions, and progression to metastatic IHCC. These studies provide a functional link between IDH mutations, hepatic cell fate, and IHCC pathogenesis, and present a novel genetically engineered mouse model of IDH-driven malignancy.
Assuntos
Neoplasias dos Ductos Biliares/patologia , Diferenciação Celular/genética , Colangiocarcinoma/patologia , Fator 4 Nuclear de Hepatócito/antagonistas & inibidores , Hepatócitos/patologia , Isocitrato Desidrogenase/genética , Proteínas Mutantes/metabolismo , Animais , Neoplasias dos Ductos Biliares/enzimologia , Neoplasias dos Ductos Biliares/genética , Ductos Biliares Intra-Hepáticos/enzimologia , Ductos Biliares Intra-Hepáticos/patologia , Divisão Celular/genética , Linhagem da Célula/genética , Colangiocarcinoma/enzimologia , Colangiocarcinoma/genética , Modelos Animais de Doenças , Feminino , Glutaratos/metabolismo , Fator 4 Nuclear de Hepatócito/biossíntese , Fator 4 Nuclear de Hepatócito/genética , Fator 4 Nuclear de Hepatócito/metabolismo , Hepatócitos/enzimologia , Hepatócitos/metabolismo , Humanos , Isocitrato Desidrogenase/metabolismo , Masculino , Camundongos , Camundongos Transgênicos , Proteínas Mutantes/genética , Mutação/genética , Metástase Neoplásica , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas p21(ras) , Células-Tronco/patologia , Proteínas ras/genética , Proteínas ras/metabolismoRESUMO
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. We demonstrate that AG-348 can increase the activity of wild-type and mutant PK enzymes in biochemical assays and in patient red blood cells treated ex vivo. These data illustrate the potential for AG-348 to restore the glycolytic pathway activity in patients with PK deficiency and ultimately lead to clinical benefit.
Assuntos
Ativadores de Enzimas/farmacologia , Ativadores de Enzimas/uso terapêutico , Eritrócitos/enzimologia , Piruvato Quinase/deficiência , Piruvato Quinase/metabolismo , Quinolinas/farmacologia , Quinolinas/uso terapêutico , Sulfonamidas/farmacologia , Sulfonamidas/uso terapêutico , Anemia Hemolítica Congênita não Esferocítica , Animais , Ativação Enzimática/efeitos dos fármacos , Ativadores de Enzimas/química , Eritrócitos/efeitos dos fármacos , Humanos , Cinética , Camundongos , Piperazinas , Piruvato Quinase/efeitos dos fármacos , Erros Inatos do Metabolismo dos Piruvatos , Quinolinas/química , Proteínas Recombinantes/metabolismo , Sulfonamidas/química , Doadores de TecidosRESUMO
We have identified a series of hydantoin-derived TNF-a converting enzyme (TACE) inhibitors containing a pendant fused bi-heteroaryl group, which demonstrate sub-nanomolar potency (Ki), excellent activity in human whole blood assay, and improved DMPK profiles over prior series.
Assuntos
Proteína ADAM17/antagonistas & inibidores , Hidantoínas/química , Inibidores de Proteases/química , Proteína ADAM17/metabolismo , Animais , Área Sob a Curva , Cães , Ativação Enzimática/efeitos dos fármacos , Meia-Vida , Haplorrinos , Humanos , Hidantoínas/síntese química , Hidantoínas/farmacologia , Inibidores de Proteases/síntese química , Inibidores de Proteases/farmacologia , Curva ROC , Ratos , Relação Estrutura-AtividadeRESUMO
Two mutant forms (R132H and R132C) of isocitrate dehydrogenase 1 (IDH1) have been associated with a number of cancers including glioblastoma and acute myeloid leukemia. These mutations confer a neomorphic activity of 2-hydroxyglutarate (2-HG) production, and 2-HG has previously been implicated as an oncometabolite. Inhibitors of mutant IDH1 can potentially be used to treat these diseases. In this study, we investigated the mechanism of action of a newly discovered inhibitor, ML309, using biochemical, cellular, and biophysical approaches. Substrate binding and product inhibition studies helped to further elucidate the IDH1 R132H catalytic cycle. This rapidly equilibrating inhibitor is active in both biochemical and cellular assays. The (+) isomer is active (IC50 = 68 nm), whereas the (-) isomer is over 400-fold less active (IC50 = 29 µm) for IDH1 R132H inhibition. IDH1 R132C was similarly inhibited by (+)-ML309. WT IDH1 was largely unaffected by (+)-ML309 (IC50 >36 µm). Kinetic analyses combined with microscale thermophoresis and surface plasmon resonance indicate that this reversible inhibitor binds to IDH1 R132H competitively with respect to α-ketoglutarate and uncompetitively with respect to NADPH. A reaction scheme for IDH1 R132H inhibition by ML309 is proposed in which ML309 binds to IDH1 R132H after formation of the IDH1 R132H NADPH complex. ML309 was also able to inhibit 2-HG production in a glioblastoma cell line (IC50 = 250 nm) and had minimal cytotoxicity. In the presence of racemic ML309, 2-HG levels drop rapidly. This drop was sustained until 48 h, at which point the compound was washed out and 2-HG levels recovered.
Assuntos
Acetamidas/farmacologia , Benzimidazóis/farmacologia , Fenômenos Biofísicos , Inibidores Enzimáticos/farmacologia , Isocitrato Desidrogenase/antagonistas & inibidores , Isocitrato Desidrogenase/genética , Proteínas Mutantes/antagonistas & inibidores , Proteínas Mutantes/genética , Mutação , Acetamidas/metabolismo , Acetamidas/farmacocinética , Animais , Benzimidazóis/metabolismo , Benzimidazóis/farmacocinética , Linhagem Celular Tumoral , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/farmacocinética , Humanos , Isocitrato Desidrogenase/metabolismo , Camundongos , Proteínas Mutantes/metabolismo , Bibliotecas de Moléculas Pequenas/metabolismo , Bibliotecas de Moléculas Pequenas/farmacocinética , Bibliotecas de Moléculas Pequenas/farmacologiaRESUMO
A new class of quinoline-based kinase inhibitors has been discovered that both disrupt cyclin dependent 2 (CDK2) interaction with its cyclin A subunit and act as ATP competitive inhibitors. The key strategy for discovering this class of protein-protein disrupter compounds was to screen the monomer CDK2 in an affinity-selection/mass spectrometry-based technique and to perform secondary assays that identified compounds that bound only to the inactive CDK2 monomer and not the active CDK2/cyclin A heterodimer. Through a series of chemical modifications the affinity (Kd) of the original hit improved from 1 to 0.005µM.
Assuntos
Ciclina A/antagonistas & inibidores , Quinase 2 Dependente de Ciclina/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Quinolinas/farmacologia , Cristalografia por Raios X , Ciclina A/química , Ciclina A/metabolismo , Quinase 2 Dependente de Ciclina/química , Quinase 2 Dependente de Ciclina/metabolismo , Relação Dose-Resposta a Droga , Humanos , Modelos Moleculares , Estrutura Molecular , Inibidores de Proteínas Quinases/química , Quinolinas/química , Relação Estrutura-AtividadeRESUMO
The ribonucleotide reductase (RNR) enzyme is a heteromer of RRM1 and RRM2 subunits. The active enzyme catalyzes de novo reduction of ribonucleotides to generate deoxyribonucleotides (dNTPs), which are required for DNA replication and DNA repair processes. Complexity in the generation of physiologically relevant, active RRM1/RRM2 heterodimers was perceived as limiting to the identification of selective RRM1 inhibitors by high-throughput screening of compound libraries and led us to seek alternative methods to identify lead series. In short, we found that gemcitabine, as its diphosphate metabolite, represents one of the few described active site inhibitors of RRM1. We herein describe the identification of novel 5'-amino gemcitabine analogs as potent RRM1 inhibitors through in-cell phenotypic screening.
Assuntos
Desoxicitidina/análogos & derivados , Proteínas Supressoras de Tumor/antagonistas & inibidores , Linhagem Celular Tumoral , Desoxicitidina/química , Desoxicitidina/farmacologia , Relação Dose-Resposta a Droga , Ensaios de Triagem em Larga Escala , Humanos , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Ribonucleosídeo Difosfato Redutase , Relação Estrutura-Atividade , GencitabinaRESUMO
TNF-α converting enzyme (TACE) inhibitors are promising agents to treat inflammatory disorders and cancer. We have investigated novel tartrate diamide TACE inhibitors where the tartrate core binds to zinc in a unique tridentate fashion. Incorporating (R)-2-(2-N-alkylaminothiazol-4-yl)pyrrolidines into the left hand side amide of the tartrate scaffold led to the discovery of potent and selective TACE inhibitors, some of which exhibited good rat oral bioavailability.
Assuntos
Proteínas ADAM/antagonistas & inibidores , Amidas/farmacologia , Inibidores Enzimáticos/farmacologia , Pirrolidinas/química , Tartaratos/química , Proteína ADAM17 , Amidas/síntese química , Amidas/química , Animais , Disponibilidade Biológica , Ativação Enzimática/efeitos dos fármacos , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Estrutura Molecular , RatosRESUMO
We disclose inhibitors of TNF-alpha converting enzyme (TACE) designed around a hydantoin zinc binding moiety. Crystal structures of inhibitors bound to TACE revealed monodentate coordination of the hydantoin to the zinc. SAR, X-ray, and modeling designs are described. To our knowledge, these are the first reported X-ray structures of TACE with a hydantoin zinc ligand.
Assuntos
Proteínas ADAM/antagonistas & inibidores , Descoberta de Drogas , Inibidores Enzimáticos/farmacologia , Hidantoínas/farmacologia , Proteína ADAM17 , Inibidores Enzimáticos/química , Hidantoínas/química , Ligação de Hidrogênio , Modelos Moleculares , Relação Estrutura-Atividade , Difração de Raios XRESUMO
A novel series of TNF-alpha convertase (TACE) inhibitors which are non-hydroxamate have been discovered. These compounds are bis-amides of L-tartaric acid (tartrate) and coordinate to the active site zinc in a tridentate manner. They are selective for TACE over other MMP's. We report the first X-ray crystal structure for a tartrate-based TACE inhibitor.
Assuntos
Proteínas ADAM/antagonistas & inibidores , Proteínas ADAM/metabolismo , Descoberta de Drogas , Inibidores de Proteases/química , Tartaratos/química , Fator de Necrose Tumoral alfa/metabolismo , Proteína ADAM17 , Sítios de Ligação , Técnicas de Química Combinatória , Cristalografia por Raios X , Descoberta de Drogas/métodos , Humanos , Inibidores de Proteases/metabolismo , Inibidores de Proteases/farmacologia , Tartaratos/metabolismo , Tartaratos/farmacologiaRESUMO
Our research on hydantoin based TNF-α converting enzyme (TACE) inhibitors has led to an acetylene containing series that demonstrates sub-nanomolar potency (K(i)) as well as excellent activity in human whole blood. These studies led to the discovery of highly potent TACE inhibitors with good DMPK profiles.
Assuntos
Proteínas ADAM/antagonistas & inibidores , Anti-Inflamatórios/química , Artrite Reumatoide/tratamento farmacológico , Inibidores de Proteases/química , Proteínas ADAM/metabolismo , Proteína ADAM17 , Acetileno/análogos & derivados , Acetileno/farmacocinética , Acetileno/uso terapêutico , Animais , Anti-Inflamatórios/farmacocinética , Anti-Inflamatórios/uso terapêutico , Cães , Haplorrinos , Humanos , Inibidores de Proteases/farmacocinética , Inibidores de Proteases/uso terapêutico , RatosRESUMO
The syntheses and structure-activity relationships of the tartrate-based TACE inhibitors are discussed. The optimization of both the prime and non-prime sites led to compounds with picomolar activity. Several analogs demonstrated good rat pharmacokinetics.
Assuntos
Proteínas ADAM/antagonistas & inibidores , Inibidores de Proteases/química , Tartaratos/química , Proteínas ADAM/metabolismo , Proteína ADAM17 , Animais , Sítios de Ligação , Simulação por Computador , Inibidores de Proteases/síntese química , Inibidores de Proteases/farmacocinética , Ratos , Relação Estrutura-Atividade , Tartaratos/síntese química , Tartaratos/farmacocinéticaRESUMO
Inhibitors of mutant isocitrate dehydrogenase (mIDH) 1 and 2 cancer-associated enzymes prevent the accumulation of the oncometabolite d-2-hydroxyglutarate (2-HG) and are under clinical investigation for the treatment of several cancers harboring an IDH mutation. Herein, we describe the discovery of vorasidenib (AG-881), a potent, oral, brain-penetrant dual inhibitor of both mIDH1 and mIDH2. X-ray cocrystal structures allowed us to characterize the compound binding site, leading to an understanding of the dual mutant inhibition. Furthermore, vorasidenib penetrates the brain of several preclinical species and inhibits 2-HG production in glioma tissue by >97% in an orthotopic glioma mouse model. Vorasidenib represents a novel dual mIDH1/2 inhibitor and is currently in clinical development for the treatment of low-grade mIDH glioma.
RESUMO
The present paper describes a novel series of HCV RNA polymerase inhibitors based on a pyrazolo[1,5-a]pyrimidine scaffold bearing hydrophobic groups and an acidic functionality. Several compounds were optimized to low nanomolar potencies in a biochemical RdRp assay. SAR trends clearly reveal a stringent preference for a cyclohexyl group as one of the hydrophobes, and improved activities for carboxylic acid derivatives.
Assuntos
RNA Polimerases Dirigidas por DNA/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Hepatite C/enzimologia , Pirazóis/farmacologia , Pirimidinas/farmacologia , RNA Viral/efeitos dos fármacos , RNA Polimerase Dependente de RNA/antagonistas & inibidores , Avaliação Pré-Clínica de Medicamentos , Hepacivirus , Hepatite C/virologia , Concentração Inibidora 50 , Peso Molecular , Bibliotecas de Moléculas PequenasRESUMO
A series of 4H-pyrazolo[1,5-a]pyrimidin-7-one derivatives was synthesized and evaluated for inhibitory activity against HCV NS5B RNA-dependent RNA polymerase. A number of these compounds exhibited potent activity in enzymatic assay. The synthesis and structure-activity relationship are also described.
Assuntos
Antivirais/farmacologia , Hepacivirus/enzimologia , Pirazóis/farmacologia , Pirimidinas/farmacologia , Proteínas não Estruturais Virais/antagonistas & inibidores , Proteínas não Estruturais Virais/metabolismo , Antivirais/química , Modelos Moleculares , Ligação Proteica , Pirazóis/química , Pirimidinas/química , RNA Polimerase Dependente de RNA/antagonistas & inibidores , RNA Polimerase Dependente de RNA/metabolismo , Relação Estrutura-AtividadeRESUMO
Squalene epoxidase (SQLE), also known as squalene monooxygenase, catalyzes the stereospecific conversion of squalene to 2,3(S)-oxidosqualene, a key step in cholesterol biosynthesis. SQLE inhibition is targeted for the treatment of hypercholesteremia, cancer, and fungal infections. However, lack of structure-function understanding has hindered further progression of its inhibitors. We have determined the first three-dimensional high-resolution crystal structures of human SQLE catalytic domain with small molecule inhibitors (2.3 Å and 2.5 Å). Comparison with its unliganded state (3.0 Å) reveals conformational rearrangements upon inhibitor binding, thus allowing deeper interpretation of known structure-activity relationships. We use the human SQLE structure to further understand the specificity of terbinafine, an approved agent targeting fungal SQLE, and to provide the structural insights into terbinafine-resistant mutants encountered in the clinic. Collectively, these findings elucidate the structural basis for the specificity of the epoxidation reaction catalyzed by SQLE and enable further rational development of next-generation inhibitors.
Assuntos
Esqualeno Mono-Oxigenase/química , Esqualeno Mono-Oxigenase/metabolismo , Animais , Domínio Catalítico , Linhagem Celular , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Humanos , Insetos , Conformação Proteica , Domínios Proteicos , Esqualeno/metabolismo , Esqualeno Mono-Oxigenase/antagonistas & inibidoresRESUMO
Aberrant metabolism of cancer cells is well appreciated, but the identification of cancer subsets with specific metabolic vulnerabilities remains challenging. We conducted a chemical biology screen and identified a subset of neuroendocrine tumors displaying a striking pattern of sensitivity to inhibition of the cholesterol biosynthetic pathway enzyme squalene epoxidase (SQLE). Using a variety of orthogonal approaches, we demonstrate that sensitivity to SQLE inhibition results not from cholesterol biosynthesis pathway inhibition, but rather surprisingly from the specific and toxic accumulation of the SQLE substrate, squalene. These findings highlight SQLE as a potential therapeutic target in a subset of neuroendocrine tumors, particularly small cell lung cancers.
Assuntos
Antineoplásicos/farmacologia , Sistemas de Liberação de Medicamentos , Ensaios de Seleção de Medicamentos Antitumorais , Esqualeno Mono-Oxigenase/antagonistas & inibidores , Esqualeno Mono-Oxigenase/metabolismo , Antineoplásicos/química , Linhagem Celular Tumoral , Colesterol/biossíntese , Deleção de Genes , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , HumanosRESUMO
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. Here, we report the discovery of AG-120 (ivosidenib), an inhibitor of the IDH1 mutant enzyme that exhibits profound 2-HG lowering in tumor models and the ability to effect differentiation of primary patient AML samples ex vivo. Preliminary data from phase 1 clinical trials enrolling patients with cancers harboring an IDH1 mutation indicate that AG-120 has an acceptable safety profile and clinical activity.