ABSTRACT
We report the discovery of a novel aminopyrazine series of PI3Kα inhibitors, designed by hybridizing two known scaffolds of PI3K inhibitors. We describe the progress achieved from the first compounds plagued with poor general kinase selectivity to compounds showing high selectivity for PI3Kα over PI3Kß and excellent general kinase selectivity. This effort culminated with the identification of compound 5 displaying high potency and selectivity, and suitable physiochemical and pharmacokinetic properties for oral administration. In vivo, compound 5 showed good inhibition of tumour growth (86% tumour growth inhibition at 50mg/kg twice daily orally) in the MCF7 xenograft model in mice.
Subject(s)
Drug Discovery , Phosphoinositide-3 Kinase Inhibitors , Protein Kinase Inhibitors/pharmacology , Pyrazines/pharmacology , Class I Phosphatidylinositol 3-Kinases , Dose-Response Relationship, Drug , Humans , Molecular Docking Simulation , Molecular Structure , Phosphatidylinositol 3-Kinases/metabolism , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/chemistry , Pyrazines/chemical synthesis , Pyrazines/chemistry , Structure-Activity RelationshipABSTRACT
Attempts to lock the active conformation of compound 4, a PI3Kß/δ inhibitor (PI3Kß cell IC50 0.015µM), led to the discovery of a series of 8-(1-phenylpyrrolidin-2-yl)-6-carboxamide-2-morpholino-4H-chromen-4-ones, which showed high levels of potency and selectivity as PI3Kß/δ inhibitors. Compound 10 proved exquisitely potent and selective: PI3Kß cell IC50 0.0011µM in PTEN null MDA-MB-468 cell and PI3Kδ cell IC50 0.014µM in Jeko-1 B-cell, and exhibited suitable physical properties for oral administration. In vivo, compound 10 showed profound pharmacodynamic modulation of AKT phosphorylation in a mouse PTEN-null PC3 prostate tumour xenograft after a single oral dose and gave excellent tumour growth inhibition in the same model after chronic oral dosing. Based on these results, compound 10 was selected as one of our PI3Kß/δ preclinical candidates.
Subject(s)
Antineoplastic Agents/chemistry , Antineoplastic Agents/therapeutic use , Benzopyrans/chemistry , Benzopyrans/therapeutic use , PTEN Phosphohydrolase/genetics , Phosphoinositide-3 Kinase Inhibitors , Prostatic Neoplasms/drug therapy , Animals , Antineoplastic Agents/pharmacokinetics , Antineoplastic Agents/pharmacology , Benzopyrans/pharmacokinetics , Benzopyrans/pharmacology , Cell Line, Tumor , Class Ia Phosphatidylinositol 3-Kinase/metabolism , Dogs , Gene Deletion , Humans , Male , Mice, Nude , Molecular Docking Simulation , Morpholinos/chemistry , Morpholinos/pharmacokinetics , Morpholinos/pharmacology , Morpholinos/therapeutic use , Prostate/drug effects , Prostate/metabolism , Prostatic Neoplasms/genetics , Prostatic Neoplasms/metabolism , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacokinetics , Protein Kinase Inhibitors/pharmacology , Protein Kinase Inhibitors/therapeutic useABSTRACT
We report the discovery and optimisation of a series of 8-(2,3-dihydro-1,4-benzoxazin-4-ylmethyl)-2-morpholino-4-oxo-chromene-6-carboxamides, leading to compound 16 as a potent and selective PI3Kß/δ inhibitor: PI3Kß cell IC50 0.012 µM (in PTEN null MDA-MB-468 cell) and PI3Kδ cell IC50 0.047 µM (in Jeko-1 B-cell), with good pharmacokinetics and physical properties. In vivo, 16 showed profound pharmacodynamic modulation of AKT phosphorylation in a mouse PTEN-deficient PC3 prostate tumour xenograft after a single oral dose and gave excellent tumour growth inhibition in the same model after chronic oral dosing. Compound 16 was selected as a preclinical candidate for the treatment of PTEN-deficient tumours.
Subject(s)
Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Isoenzymes/antagonists & inhibitors , Morpholinos/chemistry , Morpholinos/pharmacology , PTEN Phosphohydrolase/genetics , Phosphoinositide-3 Kinase Inhibitors , Animals , Cell Line, Tumor , Humans , Mice , PhosphorylationABSTRACT
Starting from potent inhibitors of PI3Kα having poor general kinase selectivity (e.g., 1 and 2), optimisation of this series led to the identification of 25, a potent inhibitor of PI3Kα (wild type, E545K and H1047R mutations) and PI3Kδ, selective versus PI3Kß and PI3Kγ, with excellent general kinase selectivity. Compound 25 displayed low metabolic turnover and suitable physical properties for oral administration. In vivo, compound 25 showed pharmacodynamic modulation of AKT phosphorylation and near complete inhibition of tumour growth (93% tumour growth inhibition) in a murine H1047R PI3Kα mutated SKOV-3 xenograft tumour model after chronic oral administration at 25mg/kg b.i.d. Compound 25, also known as AZD8835, is currently in phase I clinical trials.
Subject(s)
Antineoplastic Agents/pharmacology , Oxadiazoles/pharmacology , Phosphoinositide-3 Kinase Inhibitors , Piperidines/pharmacology , Protein Kinase Inhibitors/pharmacology , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacokinetics , Cell Line, Tumor , Dogs , Humans , Mice , Mice, Nude , Mice, SCID , Molecular Docking Simulation , Oxadiazoles/chemical synthesis , Piperidines/chemical synthesis , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/pharmacokinetics , Rats , Xenograft Model Antitumor AssaysABSTRACT
Starting from compound 1, a potent PI3Kα inhibitor having poor general kinase selectivity, we used structural data and modelling to identify key exploitable differences between PI3Kα and the other kinases. This approach led us to design chemical modifications of the central pyrazole, which solved the poor kinase selectivity seen as a strong liability for the initial compound 1. Amongst the modifications explored, a 1,3,4-triazole ring (as in compound 4) as a replacement of the initial pyrazole provided good potency against PI3Kα, with excellent kinase selectivity.
Subject(s)
Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Phosphoinositide-3 Kinase Inhibitors , Amino Acid Sequence , Binding Sites , Biomarkers, Tumor/antagonists & inhibitors , Biomarkers, Tumor/chemistry , Biomarkers, Tumor/genetics , Cell Line, Tumor , Class I Phosphatidylinositol 3-Kinases , Drug Design , Enzyme Inhibitors/chemical synthesis , Humans , Models, Molecular , Mutant Proteins/antagonists & inhibitors , Mutant Proteins/chemistry , Mutant Proteins/genetics , Phosphatidylinositol 3-Kinases/chemistry , Phosphatidylinositol 3-Kinases/genetics , Pyrazoles/chemical synthesis , Pyrazoles/chemistry , Pyrazoles/pharmacology , Structure-Activity Relationship , Triazoles/chemical synthesis , Triazoles/chemistry , Triazoles/pharmacologyABSTRACT
Several studies have highlighted the dependency of PTEN deficient tumors to PI3Kß activity and specific inhibition of PI3Kδ has been shown activity against human B-cell cancers. We describe the discovery and optimization of a series of 8-(1-anilino)ethyl)-2-morpholino-4-oxo-4H-chromene-6-carboxamides as PI3Kß/δ inhibitors, which led to the discovery of the clinical candidate 13, also known as AZD8186. On the basis of the lower lipophilicity of the chromen-4-one core compared to the previously utilized pyrido[1,2-a]pyrimid-4-one core, this series of compounds displayed high metabolic stability and suitable physical properties for oral administration. Compound 13 showed profound pharmacodynamic modulation of p-Akt in PTEN-deficient PC3 prostate tumor bearing mice after oral administration and showed complete inhibition of tumor growth in the mouse PTEN-deficient PC3 prostate tumor xenograft model. 13 was selected as a clinical candidate for treatment of PTEN-deficient cancers and has recently entered phase I clinical trials.
Subject(s)
Aniline Compounds/chemical synthesis , Chromones/chemical synthesis , Neoplasms, Experimental/drug therapy , PTEN Phosphohydrolase/deficiency , Phosphoinositide-3 Kinase Inhibitors , Aniline Compounds/pharmacology , Animals , Chromones/pharmacology , Dogs , Drug Discovery , Humans , Male , Mice , Neoplasms, Experimental/chemistry , Structure-Activity RelationshipABSTRACT
Starting from TGX-221, we designed a series of 9-(1-anilinoethyl)-2-morpholino-4-oxo-pyrido[1,2-a]pyrimidine-7-carboxamides as potent and selective PI3Kß/δ inhibitors. Structure-activity relationships and structure-property relationships around the aniline and the amide substituents are discussed. We identified compounds 17 and 18, which showed profound pharmacodynamic modulation of phosphorylated Akt in the PC3 prostate tumour xenograft, after a single oral dose. Compound 17 also gave significant inhibition of tumour growth in the PC3 prostate tumour xenograft model after chronic oral dosing.
Subject(s)
Amides/pharmacology , Antineoplastic Agents/pharmacology , Drug Discovery , Neoplasms, Experimental/drug therapy , PTEN Phosphohydrolase/deficiency , Phosphoinositide-3 Kinase Inhibitors , Protein Kinase Inhibitors/pharmacology , Administration, Oral , Amides/administration & dosage , Amides/chemistry , Animals , Antineoplastic Agents/administration & dosage , Antineoplastic Agents/chemistry , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , Humans , Mice , Molecular Structure , Neoplasms, Experimental/enzymology , Neoplasms, Experimental/pathology , PTEN Phosphohydrolase/metabolism , Phosphatidylinositol 3-Kinases/metabolism , Protein Kinase Inhibitors/administration & dosage , Protein Kinase Inhibitors/chemistry , Structure-Activity RelationshipABSTRACT
Deregulation of HER family signaling promotes proliferation and tumor cell survival and has been described in many human cancers. Simultaneous, equipotent inhibition of EGFR-, HER2-, and HER3-mediated signaling may be of clinical utility in cancer settings where the selective EGFR or HER2 therapeutic agents are ineffective or only modestly active. We describe the discovery of AZD8931 (2), an equipotent, reversible inhibitor of EGFR-, HER2-, and HER3-mediated signaling and the structure-activity relationships within this series. Docking studies based on a model of the HER2 kinase domain helped rationalize the increased HER2 activity seen with the methyl acetamide side chain present in AZD8931. AZD8931 exhibited good pharmacokinetics in preclinical species and showed superior activity in the LoVo tumor growth efficacy model compared to close analogues. AZD8931 is currently being evaluated in human clinical trials for the treatment of cancer.
ABSTRACT
Potent antagonists of the integrin α(5)ß(1), which are RGD mimetics built from tyrosine are described. This letter describes the optimization of in vitro potency obtained by variation of two parts of the molecule, the basic group and the linker between the basic group and the phenyl central core.
Subject(s)
Integrin alpha5beta1/antagonists & inhibitors , Oligopeptides/chemical synthesis , Tyrosine/analogs & derivatives , Tyrosine/chemical synthesis , Cell Adhesion/drug effects , Cell Survival/drug effects , Fibrinogen/chemistry , Fibronectins/chemistry , Humans , Integrin alpha5beta1/metabolism , K562 Cells , Models, Molecular , Molecular Mimicry , Oligopeptides/pharmacology , Serum Albumin/chemistry , Structure-Activity Relationship , Tyrosine/pharmacologyABSTRACT
Potent antagonists of the integrin α(5)ß(1), which are RGD mimetics built from tyrosine are described. This paper describes the optimization of in vitro potency obtained by variation of two parts of the molecule, the central aromatic core and the amide moiety.
Subject(s)
Integrin alpha5beta1/antagonists & inhibitors , Oligopeptides/chemical synthesis , Tyrosine/analogs & derivatives , Tyrosine/chemical synthesis , Cell Adhesion/drug effects , Cell Survival/drug effects , Fibrinogen/chemistry , Fibronectins/chemistry , Humans , Integrin alpha5beta1/metabolism , K562 Cells , Models, Molecular , Molecular Mimicry , Oligopeptides/pharmacology , Serum Albumin/chemistry , Structure-Activity Relationship , Tyrosine/pharmacologyABSTRACT
A new series of quinoline ether inhibitors, which potently and selectively inhibit PDGFR tyrosine kinases, is described in this Letter. Compounds 23 and 33 are selective, low nanomolar inhibitors of PDGFRα and ß, display good pharmacokinetics in rat and dog and are active in vivo at low doses when given orally twice daily. Further evaluation of these compounds is warranted.
Subject(s)
Ethers/pharmacology , Quinolines/pharmacology , Receptors, Platelet-Derived Growth Factor/antagonists & inhibitors , Animals , Dogs , Dose-Response Relationship, Drug , Drug Discovery , Protein-Tyrosine Kinases/antagonists & inhibitors , RatsABSTRACT
The partnership between rational synthesis design and mass-triggered preparative LCMS is a powerful one, capable of furnishing very large libraries in a selective manner in a very short space of time. Herein, we communicate one example of possibly a perfect marriage between the synthetic chemistry and the subsequent purification method employed, affording a â¼1000-member library supplying 50 mg on average of final compound in less than a month.
Subject(s)
Chemistry Techniques, Synthetic/methods , Pyrazines/chemical synthesis , Small Molecule Libraries/chemical synthesis , Molecular Structure , Pyrazines/chemistry , Small Molecule Libraries/chemistry , StereoisomerismABSTRACT
Optimization of our bis-anilino-pyrimidine series of EphB4 kinase inhibitors led to the discovery of compound 12 which incorporates a key m-hydroxymethylene group on the C4 aniline. 12 displays a good kinase selectivity profile, good physical properties and pharmacokinetic parameters, suggesting it is a suitable candidate to investigate the therapeutic potential of EphB4 kinase inhibitors.
Subject(s)
Aniline Compounds/chemistry , Benzyl Alcohol/chemistry , Protein Kinase Inhibitors/chemistry , Pyrimidines/chemistry , Receptor, EphB4/antagonists & inhibitors , Administration, Oral , Aniline Compounds/chemical synthesis , Aniline Compounds/pharmacokinetics , Animals , Benzyl Alcohol/chemical synthesis , Benzyl Alcohol/pharmacokinetics , Binding Sites , Computer Simulation , Crystallography, X-Ray , Drug Evaluation, Preclinical , Mice , Mice, Nude , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/pharmacokinetics , Pyrimidines/chemical synthesis , Pyrimidines/pharmacokinetics , Receptor, EphB4/metabolism , Structure-Activity RelationshipABSTRACT
Src family kinases (SFKs) are nonreceptor tyrosine kinases that are reported to be critical for cancer progression. We report here a novel subseries of C-5-substituted anilinoquinazolines that display high affinity and specificity for the tyrosine kinase domain of the c-Src and Abl enzymes. These compounds exhibit high selectivity for SFKs over a panel of recombinant protein kinases, excellent pharmacokinetics, and in vivo activity following oral dosing. N-(5-Chloro-1,3-benzodioxol-4-yl)-7-[2-(4-methylpiperazin-1-yl)ethoxy]-5-(tetrahydro-2H-pyran-4-yloxy)quinazolin-4-amine (AZD0530) inhibits c-Src and Abl enzymes at low nanomolar concentrations and is highly selective over a range of kinases. AZD0530 displays excellent pharmacokinetic parameters in animal preclinically and in man (t(1/2) = 40 h). AZD0530 is a potent inhibitor of tumor growth in a c-Src-transfected 3T3-fibroblast xenograft model in vivo and led to a significant increase in survival in a highly aggressive, orthotopic model of human pancreatic cancer when dosed orally once daily. AZD0530 is currently undergoing clinical evaluation in man.
Subject(s)
Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacology , Benzodioxoles/chemical synthesis , Benzodioxoles/pharmacology , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacology , Protein-Tyrosine Kinases/antagonists & inhibitors , Protein-Tyrosine Kinases/chemistry , Quinazolines/chemical synthesis , Quinazolines/pharmacology , src-Family Kinases/antagonists & inhibitors , src-Family Kinases/chemistry , 3T3 Cells , Animals , Antineoplastic Agents/pharmacokinetics , Benzodioxoles/pharmacokinetics , Cell Proliferation/drug effects , Chemical Phenomena , Chemistry, Physical , Crystallography, X-Ray , Dogs , Enzyme Inhibitors/pharmacokinetics , Female , Humans , Indicators and Reagents , Male , Mice , Mice, Nude , Models, Molecular , Neoplasm Invasiveness/prevention & control , Quinazolines/pharmacokinetics , Rats , Solubility , Structure-Activity Relationship , Thermodynamics , Transplantation, Heterologous , src-Family Kinases/biosynthesisABSTRACT
The synthesis of a novel series of quinazolines substituted at C4 by five-membered ring aminoheterocycles is reported. Their in vitro structure-activity relationships versus Aurora A and B serine-threonine kinases is discussed. Our results demonstrate that quinazolines with a substituted aminothiazole at C4 possess potent Aurora A and B inhibitory activity and excellent selectivity against a panel of various serine-threonine and tyrosine kinases, as exemplified by compound 46. We found also that the position and nature of the substituent on the thiazole play key roles in cellular potency. Compounds with an acetanilide substituent at C5' have the greatest cellular activity. The importance of the C5' position for substitution has been rationalized by ab initio molecular orbital calculations. Results show that the planar conformation with the sulfur of the thiazole next to the quinazoline N-3 is strongly favored over the other possible planar conformation. Compound 46 is a potent suppressor of the expression of phospho-histone H3 in tumor cells in vitro as well as in vivo, where 46, administered as its phosphate prodrug 54, suppresses the expression of phospho-histone H3 in subcutaneously implanted tumors in nude mice.
Subject(s)
Antineoplastic Agents/chemical synthesis , Organophosphates/chemical synthesis , Protein Serine-Threonine Kinases/antagonists & inhibitors , Quinazolines/chemical synthesis , Thiazoles/chemical synthesis , Animals , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Aurora Kinase A , Aurora Kinases , Cell Line, Tumor , Histones/antagonists & inhibitors , Histones/biosynthesis , Humans , Mice , Mice, Nude , Models, Molecular , Molecular Structure , Neoplasm Transplantation , Organophosphates/chemistry , Organophosphates/pharmacology , Phosphoproteins/antagonists & inhibitors , Phosphoproteins/biosynthesis , Prodrugs/chemical synthesis , Prodrugs/chemistry , Prodrugs/pharmacology , Protein Serine-Threonine Kinases/chemistry , Quantum Theory , Quinazolines/chemistry , Quinazolines/pharmacology , Structure-Activity Relationship , Thiazoles/chemistry , Thiazoles/pharmacology , Xenograft Model Antitumor AssaysABSTRACT
Deregulated activity of the nonreceptor tyrosine kinase c-Src is believed to result in signal transduction, cytoskeletal and adhesion changes, ultimately promoting a tumor-invasive phenotype. We report here the discovery of a new class of anilinoquinazoline inhibitors with high affinity and specificity for the tyrosine kinase domain of the c-Src enzyme. Special attention was directed toward finding inhibitors selective against KDR tyrosine kinase in order to ensure that the in vivo profile of a specific Src inhibitor could be determined. The 4-aminobenzodioxole quinazoline series gave compounds with excellent potency and selectivity. The most interesting compounds were evaluated in vivo and displayed good pharmacokinetics following oral dosing. Compounds such as the aminobenzodioxoles were shown to be potent inhibitors of tumor growth in a c-Src-transformed 3T3 xenograft model in vivo, resulting in more than 90% growth inhibition at doses as low as 6 mg/kg po once daily. Src tyrosine kinase inhibitors such as these may provide a novel therapeutic modality for targeting cancer invasion and metastasis.