ABSTRACT
The PARP inhibitor AZD2461 was developed as a next-generation agent following olaparib, the first PARP inhibitor approved for cancer therapy. In BRCA1-deficient mouse models, olaparib resistance predominantly involves overexpression of P-glycoprotein, so AZD2461 was developed as a poor substrate for drug transporters. Here we demonstrate the efficacy of this compound against olaparib-resistant tumors that overexpress P-glycoprotein. In addition, AZD2461 was better tolerated in combination with chemotherapy than olaparib in mice, which suggests that AZD2461 could have significant advantages over olaparib in the clinic. However, this superior toxicity profile did not extend to rats. Investigations of this difference revealed a differential PARP3 inhibitory activity for each compound and a higher level of PARP3 expression in bone marrow cells from mice as compared with rats and humans. Our findings have implications for the use of mouse models to assess bone marrow toxicity for DNA-damaging agents and inhibitors of the DNA damage response. Finally, structural modeling of the PARP3-active site with different PARP inhibitors also highlights the potential to develop compounds with different PARP family member specificity profiles for optimal antitumor activity and tolerability. Cancer Res; 76(20); 6084-94. ©2016 AACR.
Subject(s)
Neoplasms, Experimental/drug therapy , Phthalazines/pharmacology , Piperidines/pharmacology , Poly(ADP-ribose) Polymerase Inhibitors/pharmacology , Poly(ADP-ribose) Polymerases/physiology , ATP Binding Cassette Transporter, Subfamily B, Member 1/physiology , Animals , Bone Marrow/drug effects , Cell Line, Tumor , DNA Damage , DNA Repair , Dacarbazine/administration & dosage , Dacarbazine/analogs & derivatives , Drug Discovery , Genes, BRCA1 , Humans , Mice , Phthalazines/administration & dosage , Phthalazines/toxicity , Piperazines/administration & dosage , Piperidines/toxicity , Poly(ADP-ribose) Polymerases/chemistry , Rats , Temozolomide , Xenograft Model Antitumor AssaysABSTRACT
Here we report the discovery and optimization of a series of bivalent bromodomain and extraterminal inhibitors. Starting with the observation of BRD4 activity of compounds from a previous program, the compounds were optimized for BRD4 potency and physical properties. The optimized compound from this campaign exhibited excellent pharmacokinetic profile and exhibited high potency in vitro and in vivo effecting c-Myc downregulation and tumor growth inhibition in xenograft studies. This compound was selected as the development candidate, AZD5153. The series showed enhanced potency as a result of bivalent binding and a clear correlation between BRD4 activity and cellular potency.
Subject(s)
Antineoplastic Agents/chemistry , Heterocyclic Compounds, 2-Ring/chemistry , Nuclear Proteins/antagonists & inhibitors , Piperazines/chemistry , Transcription Factors/antagonists & inhibitors , Animals , Antineoplastic Agents/pharmacokinetics , Antineoplastic Agents/pharmacology , Caco-2 Cells , Cell Cycle Proteins , Crystallography, X-Ray , Dogs , Female , Hepatocytes/drug effects , Hepatocytes/metabolism , Heterocyclic Compounds, 2-Ring/pharmacokinetics , Heterocyclic Compounds, 2-Ring/pharmacology , Heterografts , Humans , Mice, SCID , Neoplasm Transplantation , Piperazines/pharmacokinetics , Piperazines/pharmacology , Protein Conformation , Pyrazoles , Pyridazines , Rats , Stereoisomerism , Structure-Activity RelationshipABSTRACT
Fulvestrant is an estrogen receptor (ER) antagonist administered to breast cancer patients by monthly intramuscular injection. Given its present limitations of dosing and route of administration, a more flexible orally available compound has been sought to pursue the potential benefits of this drug in patients with advanced metastatic disease. Here we report the identification and characterization of AZD9496, a nonsteroidal small-molecule inhibitor of ERα, which is a potent and selective antagonist and downregulator of ERα in vitro and in vivo in ER-positive models of breast cancer. Significant tumor growth inhibition was observed as low as 0.5 mg/kg dose in the estrogen-dependent MCF-7 xenograft model, where this effect was accompanied by a dose-dependent decrease in PR protein levels, demonstrating potent antagonist activity. Combining AZD9496 with PI3K pathway and CDK4/6 inhibitors led to further growth-inhibitory effects compared with monotherapy alone. Tumor regressions were also seen in a long-term estrogen-deprived breast model, where significant downregulation of ERα protein was observed. AZD9496 bound and downregulated clinically relevant ESR1 mutants in vitro and inhibited tumor growth in an ESR1-mutant patient-derived xenograft model that included a D538G mutation. Collectively, the pharmacologic evidence showed that AZD9496 is an oral, nonsteroidal, selective estrogen receptor antagonist and downregulator in ER(+) breast cells that could provide meaningful benefit to ER(+) breast cancer patients. AZD9496 is currently being evaluated in a phase I clinical trial. Cancer Res; 76(11); 3307-18. ©2016 AACR.
Subject(s)
Breast Neoplasms/drug therapy , Cinnamates/pharmacology , Estrogen Receptor Modulators/pharmacology , Estrogen Receptor alpha/antagonists & inhibitors , Estrogen Receptor alpha/genetics , Indoles/pharmacology , Mutation/genetics , Administration, Oral , Animals , Apoptosis/drug effects , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Cell Proliferation/drug effects , Cinnamates/administration & dosage , Drug Evaluation, Preclinical , Estrogen Receptor Modulators/administration & dosage , Estrogen Receptor alpha/chemistry , Female , Humans , Indoles/administration & dosage , Mice , Mice, Inbred NOD , Mice, SCID , Protein Conformation , Rats , Tumor Cells, Cultured , Uterus/metabolism , Uterus/pathology , Xenograft Model Antitumor AssaysABSTRACT
The discovery of an orally bioavailable selective estrogen receptor downregulator (SERD) with equivalent potency and preclinical pharmacology to the intramuscular SERD fulvestrant is described. A directed screen identified the 1-aryl-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole motif as a novel, druglike ER ligand. Aided by crystal structures of novel ligands bound to an ER construct, medicinal chemistry iterations led to (E)-3-(3,5-difluoro-4-((1R,3R)-2-(2-fluoro-2-methylpropyl)-3-methyl-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indol-1-yl)phenyl)acrylic acid (30b, AZD9496), a clinical candidate with high oral bioavailability across preclinical species that is currently being evaluated in phase I clinical trials for the treatment of advanced estrogen receptor (ER) positive breast cancer.
Subject(s)
Antineoplastic Agents/metabolism , Cinnamates/chemistry , Cinnamates/metabolism , Estrogen Antagonists/chemical synthesis , Estrogen Antagonists/pharmacology , Estrogen Receptor Modulators/chemical synthesis , Estrogen Receptor Modulators/pharmacology , Indoles/chemistry , Indoles/metabolism , Antineoplastic Agents/chemistry , Breast Neoplasms/drug therapy , Cell Line, Tumor , Cell Proliferation/drug effects , Clinical Trials, Phase I as Topic , Down-Regulation/drug effects , Drug Design , Female , Humans , Injections, Intramuscular , X-Ray DiffractionABSTRACT
Epidermal growth factor receptor (EGFR) inhibitors have been used clinically in the treatment of non-small-cell lung cancer (NSCLC) patients harboring sensitizing (or activating) mutations for a number of years. Despite encouraging clinical efficacy with these agents, in many patients resistance develops leading to disease progression. In most cases, this resistance is in the form of the T790M mutation. In addition, EGFR wild type receptor inhibition inherent with these agents can lead to dose limiting toxicities of rash and diarrhea. We describe herein the evolution of an early, mutant selective lead to the clinical candidate AZD9291, an irreversible inhibitor of both EGFR sensitizing (EGFRm+) and T790M resistance mutations with selectivity over the wild type form of the receptor. Following observations of significant tumor inhibition in preclinical models, the clinical candidate was administered clinically to patients with T790M positive EGFR-TKI resistant NSCLC and early efficacy has been observed, accompanied by an encouraging safety profile.
Subject(s)
Acrylamides/pharmacology , Aniline Compounds/pharmacology , Antineoplastic Agents/pharmacology , Carcinoma, Non-Small-Cell Lung/drug therapy , Drug Resistance, Neoplasm/genetics , ErbB Receptors/antagonists & inhibitors , Lung Neoplasms/drug therapy , Animals , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacokinetics , Carcinoma, Non-Small-Cell Lung/genetics , Chemistry Techniques, Synthetic , Drug Resistance, Neoplasm/drug effects , ErbB Receptors/genetics , Female , Humans , Inhibitory Concentration 50 , Lung Neoplasms/genetics , Male , Mice , Middle Aged , Mutation , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/pharmacokinetics , Protein Kinase Inhibitors/pharmacology , Rats, Inbred Strains , Xenograft Model Antitumor AssaysABSTRACT
Continued androgen receptor (AR) expression and signaling is a key driver in castration-resistant prostate cancer (CRPC) after classical androgen ablation therapies have failed, and therefore remains a target for the treatment of progressive disease. Here, we describe the biological characterization of AZD3514, an orally bioavailable drug that inhibits androgen-dependent and -independent AR signaling. AZD3514 modulates AR signaling through two distinct mechanisms, an inhibition of ligand-driven nuclear translocation of AR and a downregulation of receptor levels, both of which were observed in vitro and in vivo. AZD3514 inhibited testosterone-driven seminal vesicle development in juvenile male rats and the growth of androgen-dependent Dunning R3327H prostate tumors in adult rats. Furthermore, this class of compound showed antitumor activity in the HID28 mouse model of CRPC in vivo. AZD3514 is currently in phase I clinical evaluation.
Subject(s)
Androgen Receptor Antagonists/pharmacology , Antineoplastic Agents/pharmacology , Prostatic Neoplasms, Castration-Resistant/pathology , Pyridazines/pharmacology , Receptors, Androgen/metabolism , Seminal Vesicles/drug effects , Abiraterone Acetate , Androgen Receptor Antagonists/metabolism , Androstadienes/pharmacology , Animals , Antineoplastic Agents/metabolism , Benzamides , Cell Line, Tumor , Disease Models, Animal , Down-Regulation , Drug Screening Assays, Antitumor , Gene Expression Regulation, Neoplastic , HCT116 Cells , Humans , Male , Mice , Mice, Nude , Nitriles , Phenylthiohydantoin/analogs & derivatives , Phenylthiohydantoin/pharmacology , Prostatic Neoplasms, Castration-Resistant/drug therapy , Pyridazines/chemical synthesis , Pyridazines/metabolism , Rats , Rats, Wistar , Receptors, Androgen/genetics , Seminal Vesicles/growth & development , Signal Transduction/drug effects , Xenograft Model Antitumor AssaysABSTRACT
Removal of the basic piperazine nitrogen atom, introduction of a solubilising end group and partial reduction of the triazolopyridazine moiety in the previously-described lead androgen receptor downregulator 6-[4-(4-cyanobenzyl)piperazin-1-yl]-3-(trifluoromethyl)[1,2,4]triazolo[4,3-b]pyridazine (1) addressed hERG and physical property issues, and led to clinical candidate 6-(4-{4-[2-(4-acetylpiperazin-1-yl)ethoxy]phenyl}piperidin-1-yl)-3-(trifluoromethyl)-7,8-dihydro[1,2,4]triazolo[4,3-b]pyridazine (12), designated AZD3514, that is being evaluated in a Phase I clinical trial in patients with castrate-resistant prostate cancer.
Subject(s)
Down-Regulation/drug effects , Drug Discovery , Prostatic Neoplasms/drug therapy , Pyridazines/pharmacology , Receptors, Androgen/metabolism , Small Molecule Libraries/pharmacology , Animals , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , Humans , Male , Molecular Structure , Prostatic Neoplasms/pathology , Pyridazines/chemical synthesis , Pyridazines/chemistry , Small Molecule Libraries/chemical synthesis , Small Molecule Libraries/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
Chemical starting points were investigated for downregulation of the androgen receptor as an approach to treatment of advanced prostate cancer. Although prototypic steroidal downregulators such as 6a designed for intramuscular administration showed insufficient cellular potency, a medicinal chemistry program derived from a novel androgen receptor ligand 8a led to 6-[4-(4-cyanobenzyl)piperazin-1-yl]-3-(trifluoromethyl)[1,2,4]triazolo[4,3-b]pyridazine (10b), for which high plasma levels following oral administration in a preclinical model compensate for moderate cellular potency.
Subject(s)
Prostatic Neoplasms/drug therapy , Pyridazines/pharmacology , Receptors, Androgen/metabolism , Dose-Response Relationship, Drug , Down-Regulation/drug effects , Humans , Ligands , Male , Models, Molecular , Molecular Structure , Molecular Weight , Prostatic Neoplasms/metabolism , Pyridazines/chemical synthesis , Pyridazines/chemistry , Stereoisomerism , Structure-Activity RelationshipABSTRACT
We have identified a new series of C-5 substituted indazolylaminoquinazolines as potent erbB2 kinase inhibitors. The lead compound 22 showed excellent in vitro potency, good physical properties, acceptable oral pharmacokinetics in rat and dog, and low human in vitro clearance. It showed at least equivalent activity dose for dose compared to lapatinib in various erbB2- or EGFR-driven xenograft models after chronic oral administration.
Subject(s)
Antineoplastic Agents/pharmacology , ErbB Receptors/antagonists & inhibitors , Indazoles/pharmacology , Neoplasms, Experimental/drug therapy , Protein Kinase Inhibitors/pharmacology , Quinazolines/pharmacology , Receptor, ErbB-2/antagonists & inhibitors , Administration, Oral , Animals , Antineoplastic Agents/chemical synthesis , Breast Neoplasms/drug therapy , Cell Line, Tumor , Cell Proliferation/drug effects , Dogs , Epidermal Growth Factor/pharmacology , Ether-A-Go-Go Potassium Channels , Female , Hepatocytes/cytology , Hepatocytes/drug effects , Hepatocytes/metabolism , Humans , Indazoles/chemical synthesis , Keratinocytes/cytology , Keratinocytes/drug effects , Keratinocytes/metabolism , Lapatinib , Male , Metabolic Clearance Rate , Mice , Mice, Nude , Mice, SCID , Microsomes/drug effects , Molecular Structure , Phosphorylation/drug effects , Protein Kinase Inhibitors/chemical synthesis , Quinazolines/chemical synthesis , Rats , Rats, Wistar , Survival Rate , Xenograft Model Antitumor AssaysABSTRACT
Starting from initial lead 1 containing a basic 5-substituent, optimisation of the glycolamide-derived neutral 5-substituent led to potent inhibitors of erbB2 with good pharmacokinetics. Representative compounds 19 and 21 inhibited phosphorylation of erbB2 in a mouse BT474C xenograft model after oral administration.
Subject(s)
Protein Kinase Inhibitors/pharmacology , Quinazolines/pharmacology , Receptor, ErbB-2/antagonists & inhibitors , Administration, Oral , Animals , Cell Line , Magnetic Resonance Spectroscopy , Mice , Neoplasm Transplantation , Phosphorylation , Protein Kinase Inhibitors/administration & dosage , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacokinetics , Quinazolines/administration & dosage , Quinazolines/chemistry , Quinazolines/pharmacokinetics , Structure-Activity RelationshipABSTRACT
Neutral 5-substituted 4-anilinoquinazolines addressed high in vivo clearance and phospholipidosis associated with previous basic compounds. A representative compound 8a inhibited tumor growth in a mouse xenograft model when co-administered with the cytochrome P450 inhibitor 1-aminobenzotriazole (ABT), and data are consistent with pharmacology primarily reflecting inhibition of erbB2 receptor tyrosine kinase.
Subject(s)
Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Neoplasms/drug therapy , Quinazolines/chemistry , Quinazolines/pharmacology , Receptor, ErbB-2/antagonists & inhibitors , Administration, Oral , Aniline Compounds/chemistry , Animals , Antineoplastic Agents/pharmacokinetics , Antineoplastic Combined Chemotherapy Protocols , Cell Proliferation/drug effects , Dogs , Drug Synergism , Mice , Molecular Structure , Quinazolines/pharmacokinetics , Rats , Triazoles/pharmacology , Xenograft Model Antitumor AssaysABSTRACT
The structure-activity and structure-property relationships of anilinoquinazoline inhibitors of EGFR were investigated. Strategies to lower volume of distribution and shorten half-life through structure and pKa modulation are discussed.
Subject(s)
ErbB Receptors/antagonists & inhibitors , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/pharmacokinetics , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacokinetics , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Chemical Phenomena , Chemistry, Physical , ErbB Receptors/metabolism , Fluorine/chemistry , Gefitinib , Humans , Inhibitory Concentration 50 , Mice , Molecular Structure , Neoplasms/drug therapy , Neoplasms/pathology , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacology , Quinazolines/chemistry , Rats , Structure-Activity Relationship , Thiazoles/chemistry , Xenograft Model Antitumor AssaysABSTRACT
A series of novel C-5 substituted anilinoquinazolines, selected on the basis of docking experiments and overlays with ATP in the active site of EGFR tyrosine kinase, have been prepared and found to be potent inhibitors. In vivo pharmacokinetics and disease model activity are discussed.
Subject(s)
ErbB Receptors/antagonists & inhibitors , Protein Kinase Inhibitors , Quinazolines , Ribose/metabolism , Adenosine Triphosphate/metabolism , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacokinetics , Antineoplastic Agents/pharmacology , Binding Sites , Cell Proliferation/drug effects , Colonic Neoplasms/drug therapy , Female , Humans , KB Cells/drug effects , Mice , Mice, Nude , Molecular Structure , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/pharmacokinetics , Protein Kinase Inhibitors/pharmacology , Quinazolines/chemical synthesis , Quinazolines/pharmacokinetics , Quinazolines/pharmacology , Rats , Structure-Activity Relationship , Transplantation, Heterologous , Tumor Cells, CulturedABSTRACT
Starting from a 6,7-substituted quinazoline lead 4, optimisation of 5-substituted quinazolines containing an extended aniline motif led to potent and selective inhibitors of erbB2 receptor tyrosine kinase, and a representative compound 12a inhibited tumour growth in a mouse xenograft model.
