RESUMO
In our drug discovery campaigns to target the oncogenic drivers of cancers, the demand for a chemoselective, stereoselective and economical synthesis of chiral benzylamines drove the development of a catalytic zirconium hydride reduction. This methodology uses the inexpensive, bench stable zirconocene dichloride, and a novel tetrabutylammonium fluoride activation tactic to catalytically generate a metal hydride under ambient conditions. The diastereo- and chemoselectivity of this reaction was tested with the preparation of key intermediates from our discovery programs and in the scope of sulfinyl ketimines and carbonyls relevant to medicinal chemistry and natural product synthesis. A preliminary mechanistic investigation conducted into the role of tetrabutylammonium fluoride indicates that formation of a zirconocene fluoride occurs to initiate catalysis. The implications of this convenient activation approach may provide expanded roles for zirconium hydrides in catalytic transformations.
RESUMO
Chiral amine synthesis remains a significant challenge in accelerating the design cycle of drug discovery programs. A zirconium hydride, due to its high oxophilicity and lower reactivity, gave highly chemo- and stereoselective reductions of sulfinyl ketimines. The development of this zirconocene-mediated reduction helped to accelerate our drug discovery efforts and is applicable to several motifs commonly used in medicinal chemistry. Computational investigation supported a cyclic half-chair transition state to rationalize the high selectivity in benzyl systems.
Assuntos
Compostos Organometálicos , Zircônio , Química Farmacêutica , AminasRESUMO
MRTX1719 is an inhibitor of the PRMT5/MTA complex and recently entered clinical trials for the treatment of MTAP-deleted cancers. MRTX1719 is a class 3 atropisomeric compound that requires a chiral synthesis or a chiral separation step in its preparation. Here, we report the SAR and medicinal chemistry design strategy, supported by structural insights from X-ray crystallography, to discover a class 1 atropisomeric compound from the same series that does not require a chiral synthesis or a chiral separation step in its preparation.
Assuntos
Inibidores Enzimáticos , Neoplasias , Ftalazinas , Humanos , Cristalografia por Raios X , Inibidores Enzimáticos/farmacologia , Neoplasias/tratamento farmacológico , Ftalazinas/farmacologia , Proteína-Arginina N-MetiltransferasesRESUMO
SOS1 and SOS2 are guanine nucleotide exchange factors that mediate RTK-stimulated RAS activation. Selective SOS1:KRAS PPI inhibitors are currently under clinical investigation, whereas there are no reports to date of SOS2:KRAS PPI inhibitors. SOS2 activity is implicated in MAPK rebound when divergent SOS1 mutant cell lines are treated with the SOS1 inhibitor BI-3406; therefore, SOS2:KRAS inhibitors are of therapeutic interest. In this report, we detail a fragment-based screening strategy to identify X-ray cocrystal structures of five diverse fragment hits bound to SOS2.
Assuntos
Furanos , Fatores de Troca do Nucleotídeo Guanina , Proteínas Proto-Oncogênicas p21(ras) , Quinazolinas , Raios X , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Linhagem Celular , Proteína SOS1/metabolismoRESUMO
KRAS is the most frequently mutated oncogene in human cancer and facilitates uncontrolled growth through hyperactivation of the receptor tyrosine kinase (RTK)/mitogen-activated protein kinase (MAPK) pathway. The Son of Sevenless homolog 1 (SOS1) protein functions as a guanine nucleotide exchange factor (GEF) for the RAS subfamily of small GTPases and represents a druggable target in the pathway. Using a structure-based drug discovery approach, MRTX0902 was identified as a selective and potent SOS1 inhibitor that disrupts the KRAS:SOS1 protein-protein interaction to prevent SOS1-mediated nucleotide exchange on KRAS and translates into an anti-proliferative effect in cancer cell lines with genetic alterations of the KRAS-MAPK pathway. MRTX0902 augmented the antitumor activity of the KRAS G12C inhibitor adagrasib when dosed in combination in eight out of 12 KRAS G12C-mutant human non-small cell lung cancer and colorectal cancer xenograft models. Pharmacogenomic profiling in preclinical models identified cell cycle genes and the SOS2 homolog as genetic co-dependencies and implicated tumor suppressor genes (NF1 and PTEN) in resistance following combination treatment. Lastly, combined vertical inhibition of RTK/MAPK pathway signaling by MRTX0902 with inhibitors of EGFR or RAF/MEK led to greater downregulation of pathway signaling and improved antitumor responses in KRAS-MAPK pathway-mutant models. These studies demonstrate the potential clinical application of dual inhibition of SOS1 and KRAS G12C and additional SOS1 combination strategies that will aide in the understanding of SOS1 and RTK/MAPK biology in targeted cancer therapy.
RESUMO
The H1047R mutation of PIK3CA is highly prevalent in breast cancers and other solid tumors. Selectively targeting PI3KαH1047R over PI3KαWT is crucial due to the role that PI3KαWT plays in normal cellular processes, including glucose homeostasis. Currently, only one PI3KαH1047R-selective inhibitor has progressed into clinical trials, while three pan mutant (H1047R, H1047L, H1047Y, E542K, and E545K) selective PI3Kα inhibitors have also reached the clinical stage. Herein, we report the design and discovery of a series of pyridopyrimidinones that inhibit PI3KαH1047R with high selectivity over PI3KαWT, resulting in the discovery of compound 17. When dosed in the HCC1954 tumor model in mice, 17 provided tumor regressions and a clear pharmacodynamic response. X-ray cocrystal structures from several PI3Kα inhibitors were obtained, revealing three distinct binding modes within PI3KαH1047R including a previously reported cryptic pocket in the C-terminus of the kinase domain wherein we observe a ligand-induced interaction with Arg1047.
Assuntos
Antineoplásicos , Neoplasias , Camundongos , Animais , Antineoplásicos/química , Inibidores de Fosfoinositídeo-3 Quinase/farmacologia , Inibidores de Fosfoinositídeo-3 Quinase/uso terapêutico , Neoplasias/tratamento farmacológico , Mutação , Classe I de Fosfatidilinositol 3-Quinases/uso terapêuticoRESUMO
The synthesis and biological evaluation of novel Tie-2 kinase inhibitors are presented. Based on the pyrrolopyrimidine chemotype, several new series are described, including the benzimidazole series by linking a benzimidazole to the C5-position of the 4-amino-pyrrolopyrimidine core and the ketophenyl series synthesized by incorporating a ketophenyl group to the C5-position. Medicinal chemistry efforts led to potent Tie-2 inhibitors. Compound 15, a ketophenyl pyrrolopyrimidine urea analog with improved physicochemical properties, demonstrated favorable in vitro attributes as well as dose responsive and robust oral tumor growth inhibition in animal models.
Assuntos
Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Descoberta de Drogas , Neoplasias/tratamento farmacológico , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/farmacologia , Pirimidinas/farmacologia , Pirróis/farmacologia , Receptor TIE-2/antagonistas & inibidores , Animais , Antineoplásicos/administração & dosagem , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Masculino , Estrutura Molecular , Neoplasias/enzimologia , Neoplasias/patologia , Inibidores de Proteínas Quinases/administração & dosagem , Pirimidinas/síntese química , Pirimidinas/química , Pirróis/síntese química , Pirróis/química , Ratos , Ratos Sprague-Dawley , Receptor TIE-2/metabolismo , Relação Estrutura-Atividade , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The mTOR kinase regulates a variety of critical cellular processes and has become a target for the treatment of various cancers. Using a combination of property-based drug design and Free-Wilson analysis, we further optimized a series of selective mTOR inhibitors based on the (S)-6a-methyl-6a,7,9,10-tetrahydro[1,4]oxazino[3,4-h]pteridin-6(5H)-one scaffold. Our efforts resulted in 14c, which showed similar in vivo efficacy compared to previous lead 1 at 1/15 the dose, a result of its improved drug-like properties.
RESUMO
Previous studies implicated protein arginine methyltransferase 5 (PRMT5) as a synthetic lethal target for MTAP-deleted (MTAP del) cancers; however, the pharmacologic characterization of small-molecule inhibitors that recapitulate the synthetic lethal phenotype has not been described. MRTX1719 selectively inhibited PRMT5 in the presence of MTA, which is elevated in MTAP del cancers, and inhibited PRMT5-dependent activity and cell viability with >70-fold selecti-vity in HCT116 MTAP del compared with HCT116 MTAP wild-type (WT) cells. MRTX1719 demonstrated dose-dependent antitumor activity and inhibition of PRMT5-dependent SDMA modification in MTAP del tumors. In contrast, MRTX1719 demonstrated minimal effects on SDMA and viability in MTAP WT tumor xenografts or hematopoietic cells. MRTX1719 demonstrated marked antitumor activity across a panel of xenograft models at well-tolerated doses. Early signs of clinical activity were observed including objective responses in patients with MTAP del melanoma, gallbladder adenocarcinoma, mesothelioma, non-small cell lung cancer, and malignant peripheral nerve sheath tumors from the phase I/II study. SIGNIFICANCE: PRMT5 was identified as a synthetic lethal target for MTAP del cancers; however, previous PRMT5 inhibitors do not selectively target this genotype. The differentiated binding mode of MRTX1719 leverages the elevated MTA in MTAP del cancers and represents a promising therapy for the â¼10% of patients with cancer with this biomarker. See related commentary by Mulvaney, p. 2310. This article is featured in Selected Articles from This Issue, p. 2293.
Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Linhagem Celular Tumoral , Mutações Sintéticas Letais , Inibidores Enzimáticos/farmacologia , Proteína-Arginina N-MetiltransferasesRESUMO
With renewed interest in atropisomerism of drug molecules, efficient methods to experimentally determine torsion rotational energy barriers are needed. Here, we describe use of the chiral phosphoric acid solvating agent (+)-TiPSY to resolve the signals of atropisomers in 19F NMR and to use the data to study the kinetics of racemization and determine the rotational energy barrier of clinical compound MRTX1719. This method is complimentary to traditional chiral high-performance liquid chromatography (HPLC) and enhances the toolkit for chiral analysis techniques.
RESUMO
Here we describe the early stages of a fragment-based lead discovery (FBLD) project for a recently elucidated synthetic lethal target, the PRMT5/MTA complex, for the treatment of MTAP-deleted cancers. Starting with five fragment/PRMT5/MTA X-ray co-crystal structures, we employed a two-phase fragment elaboration process encompassing optimization of fragment hits and subsequent fragment growth to increase potency, assess synthetic tractability, and enable structure-based drug design. Two lead series were identified, one of which led to the discovery of the clinical candidate MRTX1719.
RESUMO
SOS1 is one of the major guanine nucleotide exchange factors that regulates the ability of KRAS to cycle through its "on" and "off" states. Disrupting the SOS1:KRASG12C protein-protein interaction (PPI) can increase the proportion of GDP-loaded KRASG12C, providing a strong mechanistic rationale for combining inhibitors of the SOS1:KRAS complex with inhibitors like MRTX849 that target GDP-loaded KRASG12C. In this report, we detail the design and discovery of MRTX0902âa potent, selective, brain-penetrant, and orally bioavailable SOS1 binder that disrupts the SOS1:KRASG12C PPI. Oral administration of MRTX0902 in combination with MRTX849 results in a significant increase in antitumor activity relative to that of either single agent, including tumor regressions in a subset of animals in the MIA PaCa-2 tumor mouse xenograft model.
Assuntos
Encéfalo , Proteínas Proto-Oncogênicas p21(ras) , Acetonitrilas , Animais , Linhagem Celular Tumoral , Humanos , Camundongos , Mutação , Piperazinas , Proteínas Proto-Oncogênicas p21(ras)/genética , Pirimidinas , Proteína SOS1/metabolismoRESUMO
The PRMT5â¢MTA complex has recently emerged as a new synthetically lethal drug target for the treatment of MTAP-deleted cancers. Here, we report the discovery of development candidate MRTX1719. MRTX1719 is a potent and selective binder to the PRMT5â¢MTA complex and selectively inhibits PRMT5 activity in MTAP-deleted cells compared to MTAP-wild-type cells. Daily oral administration of MRTX1719 to tumor xenograft-bearing mice demonstrated dose-dependent inhibition of PRMT5-dependent symmetric dimethylarginine protein modification in MTAP-deleted tumors that correlated with antitumor activity. A 4-(aminomethyl)phthalazin-1(2H)-one hit was identified through a fragment-based screen, followed by X-ray crystallography, to confirm binding to the PRMT5â¢MTA complex. Fragment growth supported by structural insights from X-ray crystallography coupled with optimization of pharmacokinetic properties aided the discovery of development candidate MRTX1719.
Assuntos
Antineoplásicos/uso terapêutico , Neoplasias/tratamento farmacológico , Ftalazinas/uso terapêutico , Proteína-Arginina N-Metiltransferases/antagonistas & inibidores , Animais , Antineoplásicos/síntese química , Antineoplásicos/metabolismo , Linhagem Celular Tumoral , Desoxiadenosinas/metabolismo , Feminino , Deleção de Genes , Humanos , Camundongos Nus , Ftalazinas/síntese química , Ftalazinas/metabolismo , Ligação Proteica , Proteína-Arginina N-Metiltransferases/metabolismo , Purina-Núcleosídeo Fosforilase/deficiência , Purina-Núcleosídeo Fosforilase/genética , Tionucleosídeos/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Recent progress in targeting KRASG12C has provided both insight and inspiration for targeting alternative KRAS mutants. In this study, we evaluated the mechanism of action and anti-tumor efficacy of MRTX1133, a potent, selective and non-covalent KRASG12D inhibitor. MRTX1133 demonstrated a high-affinity interaction with GDP-loaded KRASG12D with KD and IC50 values of ~0.2 pM and <2 nM, respectively, and ~700-fold selectivity for binding to KRASG12D as compared to KRASWT. MRTX1133 also demonstrated potent inhibition of activated KRASG12D based on biochemical and co-crystal structural analyses. MRTX1133 inhibited ERK1/2 phosphorylation and cell viability in KRASG12D-mutant cell lines, with median IC50 values of ~5 nM, and demonstrated >1,000-fold selectivity compared to KRASWT cell lines. MRTX1133 exhibited dose-dependent inhibition of KRAS-mediated signal transduction and marked tumor regression (≥30%) in a subset of KRASG12D-mutant cell-line-derived and patient-derived xenograft models, including eight of 11 (73%) pancreatic ductal adenocarcinoma (PDAC) models. Pharmacological and CRISPR-based screens demonstrated that co-targeting KRASG12D with putative feedback or bypass pathways, including EGFR or PI3Kα, led to enhanced anti-tumor activity. Together, these data indicate the feasibility of selectively targeting KRAS mutants with non-covalent, high-affinity small molecules and illustrate the therapeutic susceptibility and broad dependence of KRASG12D mutation-positive tumors on mutant KRAS for tumor cell growth and survival.
Assuntos
Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Carcinoma Ductal Pancreático/metabolismo , Linhagem Celular Tumoral , Receptores ErbB/metabolismo , Humanos , Mutação/genética , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismoRESUMO
KRASG12D, the most common oncogenic KRAS mutation, is a promising target for the treatment of solid tumors. However, when compared to KRASG12C, selective inhibition of KRASG12D presents a significant challenge due to the requirement of inhibitors to bind KRASG12D with high enough affinity to obviate the need for covalent interactions with the mutant KRAS protein. Here, we report the discovery and characterization of the first noncovalent, potent, and selective KRASG12D inhibitor, MRTX1133, which was discovered through an extensive structure-based activity improvement and shown to be efficacious in a KRASG12D mutant xenograft mouse tumor model.
Assuntos
Antineoplásicos/farmacologia , Proteínas Proto-Oncogênicas p21(ras)/antagonistas & inibidores , Animais , Antineoplásicos/química , Descoberta de Drogas , Humanos , Camundongos , Modelos Moleculares , Mutação , Proteínas Proto-Oncogênicas p21(ras)/genética , Relação Estrutura-Atividade , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Pteridinones were designed based on a non-selective kinase template. Because of the uniqueness of the PI3K and mTOR binding pockets, a methyl group was introduced to C-4 position of the peteridinone core to give compounds with excellent selectivity for PI3K and mTOR. This series of compounds were further optimized to improve their potency against PI3Kα and mTOR. Finally, orally active compounds with improved solubility and robust in vivo efficacy in tumor growth inhibition were identified as well.
Assuntos
Antineoplásicos/química , Antineoplásicos/uso terapêutico , Inibidores de Fosfoinositídeo-3 Quinase , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/uso terapêutico , Pteridinas/química , Pteridinas/uso terapêutico , Serina-Treonina Quinases TOR/antagonistas & inibidores , Administração Oral , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Glioma/tratamento farmacológico , Humanos , Camundongos , Modelos Moleculares , Neoplasias/tratamento farmacológico , Fosfatidilinositol 3-Quinases/química , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/farmacologia , Pteridinas/administração & dosagem , Pteridinas/farmacologia , Solubilidade , Relação Estrutura-Atividade , Serina-Treonina Quinases TOR/química , Serina-Treonina Quinases TOR/metabolismoRESUMO
Capping off an era marred by drug development failures and punctuated by waning interest and presumed intractability toward direct targeting of KRAS, new technologies and strategies are aiding in the target's resurgence. As previously reported, the tetrahydropyridopyrimidines were identified as irreversible covalent inhibitors of KRASG12C that bind in the switch-II pocket of KRAS and make a covalent bond to cysteine 12. Using structure-based drug design in conjunction with a focused in vitro absorption, distribution, metabolism and excretion screening approach, analogues were synthesized to increase the potency and reduce metabolic liabilities of this series. The discovery of the clinical development candidate MRTX849 as a potent, selective covalent inhibitor of KRASG12C is described.
Assuntos
Antineoplásicos/farmacologia , Inibidores Enzimáticos/farmacologia , Proteínas Proto-Oncogênicas p21(ras)/antagonistas & inibidores , Animais , Antineoplásicos/química , Antineoplásicos/farmacocinética , Linhagem Celular Tumoral , Desenho de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacocinética , Humanos , Camundongos , Modelos Moleculares , Mutação , Proteínas Proto-Oncogênicas p21(ras)/química , Proteínas Proto-Oncogênicas p21(ras)/genética , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Despite decades of research, efforts to directly target KRAS have been challenging. MRTX849 was identified as a potent, selective, and covalent KRASG12C inhibitor that exhibits favorable drug-like properties, selectively modifies mutant cysteine 12 in GDP-bound KRASG12C, and inhibits KRAS-dependent signaling. MRTX849 demonstrated pronounced tumor regression in 17 of 26 (65%) KRASG12C-positive cell line- and patient-derived xenograft models from multiple tumor types, and objective responses have been observed in patients with KRASG12C-positive lung and colon adenocarcinomas. Comprehensive pharmacodynamic and pharmacogenomic profiling in sensitive and partially resistant nonclinical models identified mechanisms implicated in limiting antitumor activity including KRAS nucleotide cycling and pathways that induce feedback reactivation and/or bypass KRAS dependence. These factors included activation of receptor tyrosine kinases (RTK), bypass of KRAS dependence, and genetic dysregulation of cell cycle. Combinations of MRTX849 with agents that target RTKs, mTOR, or cell cycle demonstrated enhanced response and marked tumor regression in several tumor models, including MRTX849-refractory models. SIGNIFICANCE: The discovery of MRTX849 provides a long-awaited opportunity to selectively target KRASG12C in patients. The in-depth characterization of MRTX849 activity, elucidation of response and resistance mechanisms, and identification of effective combinations provide new insight toward KRAS dependence and the rational development of this class of agents.See related commentary by Klempner and Hata, p. 20.This article is highlighted in the In This Issue feature, p. 1.
Assuntos
Acetonitrilas/uso terapêutico , Adenocarcinoma de Pulmão/tratamento farmacológico , Antineoplásicos/uso terapêutico , Modelos Animais de Doenças , Neoplasias Pulmonares/tratamento farmacológico , Mutação , Piperazinas/uso terapêutico , Proteínas Proto-Oncogênicas p21(ras)/antagonistas & inibidores , Proteínas Proto-Oncogênicas p21(ras)/genética , Pirrolidinas/uso terapêutico , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/patologia , Animais , Apoptose , Proliferação de Células , Ensaios Clínicos Fase I como Assunto , Feminino , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos NOD , Camundongos Nus , Camundongos SCID , Pessoa de Meia-Idade , Prognóstico , Pirimidinas , Transdução de Sinais , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The title compound, C(9)H(10)N(2)O(2)S, was obtained from the treatment of ethyl 4-cyano-3-hydr-oxy-5-morpholinothio-phene-2-carboxyl-ate with concentrated HCl. The mean plane of the essentially planar dihydro-thio-phene ring is almost orthogonal to the mirror plane of the N-morpholine substituent, making a dihedral angle of 87.2â (2)°.
RESUMO
KRAS is the most frequently mutated driver oncogene in human cancer, and KRAS mutations are commonly associated with poor prognosis and resistance to standard treatment. The ability to effectively target and block the function of mutated KRAS has remained elusive despite decades of research. Recent findings have demonstrated that directly targeting KRAS-G12C with electrophilic small molecules that covalently modify the mutated codon 12 cysteine is feasible. We have discovered a series of tetrahydropyridopyrimidines as irreversible covalent inhibitors of KRAS-G12C with in vivo activity. The PK/PD and efficacy of compound 13 will be highlighted.