ABSTRACT
CD73 (ecto-5'-nucleotidase) has emerged as an attractive target for cancer immunotherapy of many cancers. CD73 catalyzes the hydrolysis of adenosine monophosphate (AMP) into highly immunosuppressive adenosine that plays a critical role in tumor progression. Herein, we report our efforts in developing orally bioavailable and highly potent small-molecule CD73 inhibitors from the reported hit molecule 2 to lead molecule 20 and then finally to compound 49. Compound 49 was able to reverse AMP-mediated suppression of CD8+ T cells and completely inhibited CD73 activity in serum samples from various cancer patients. In preclinical in vivo studies, orally administered 49 showed a robust dose-dependent pharmacokinetic/pharmacodynamic (PK/PD) relationship that correlated with efficacy. Compound 49 also demonstrated the expected immune-mediated antitumor mechanism of action and was efficacious upon oral administration not only as a single agent but also in combination with either chemotherapeutics or checkpoint inhibitor in the mouse tumor model.
Subject(s)
CD8-Positive T-Lymphocytes , Neoplasms , Mice , Animals , Nucleosides , 5'-Nucleotidase , Neoplasms/drug therapy , Disease Models, Animal , Adenosine MonophosphateABSTRACT
Glutamine serves as an important source of energy and building blocks for many tumor cells. The first step in glutamine utilization is its conversion to glutamate by the mitochondrial enzyme glutaminase. CB-839 is a potent, selective, and orally bioavailable inhibitor of both splice variants of glutaminase (KGA and GAC). CB-839 had antiproliferative activity in a triple-negative breast cancer (TNBC) cell line, HCC-1806, that was associated with a marked decrease in glutamine consumption, glutamate production, oxygen consumption, and the steady-state levels of glutathione and several tricarboxylic acid cycle intermediates. In contrast, no antiproliferative activity was observed in an estrogen receptor-positive cell line, T47D, and only modest effects on glutamine consumption and downstream metabolites were observed. Across a panel of breast cancer cell lines, GAC protein expression and glutaminase activity were elevated in the majority of TNBC cell lines relative to receptor positive cells. Furthermore, the TNBC subtype displayed the greatest sensitivity to CB-839 treatment and this sensitivity was correlated with (i) dependence on extracellular glutamine for growth, (ii) intracellular glutamate and glutamine levels, and (iii) GAC (but not KGA) expression, a potential biomarker for sensitivity. CB-839 displayed significant antitumor activity in two xenograft models: as a single agent in a patient-derived TNBC model and in a basal like HER2(+) cell line model, JIMT-1, both as a single agent and in combination with paclitaxel. Together, these data provide a strong rationale for the clinical investigation of CB-839 as a targeted therapeutic in patients with TNBC and other glutamine-dependent tumors.
Subject(s)
Antineoplastic Agents/administration & dosage , Benzeneacetamides/pharmacology , Enzyme Inhibitors/administration & dosage , Glutaminase/antagonists & inhibitors , Neoplasms, Basal Cell/drug therapy , Thiadiazoles/pharmacology , Triple Negative Breast Neoplasms/drug therapy , Administration, Oral , Animals , Antineoplastic Agents/therapeutic use , Benzeneacetamides/therapeutic use , Cell Line, Tumor , Dose-Response Relationship, Drug , Enzyme Inhibitors/therapeutic use , Female , Humans , Mammary Neoplasms, Experimental , Mice , Mice, SCID , Middle Aged , Neoplasms, Basal Cell/pathology , Sulfides/administration & dosage , Sulfides/therapeutic use , Thiadiazoles/administration & dosage , Thiadiazoles/therapeutic use , Triple Negative Breast Neoplasms/pathology , Xenograft Model Antitumor AssaysABSTRACT
The development of a new series of p38α inhibitors resulted in the identification of two clinical candidates, one of which was advanced into a phase 2 clinical study for rheumatoid arthritis. The original lead, an lck inhibitor that also potently inhibited p38α, was a screening hit from our kinase inhibitor library. This manuscript describes the optimization of the lead to p38-selective examples with good pharmacokinetic properties.
Subject(s)
Drug Discovery/methods , Mitogen-Activated Protein Kinase 14/antagonists & inhibitors , Pyridones/pharmacology , Pyridones/pharmacokinetics , Pyrimidines/pharmacology , Pyrimidines/pharmacokinetics , Administration, Oral , Arthritis, Rheumatoid/drug therapy , Biological Availability , Cell Line , Clinical Trials as Topic , Humans , Mitogen-Activated Protein Kinase 14/chemistry , Models, Molecular , Protein Conformation , Protein Kinase Inhibitors/administration & dosage , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacokinetics , Protein Kinase Inhibitors/pharmacology , Pyridones/administration & dosage , Pyridones/chemistry , Pyrimidines/administration & dosage , Pyrimidines/chemistry , Structure-Activity Relationship , Substrate SpecificityABSTRACT
A novel series of (E)-1-((2-(1-methyl-1H-imidazol-5-yl) quinolin-4-yl) methylene) thiosemicarbazides was discovered as potent inhibitors of IKKß. In this Letter we document our efforts at further optimization of this series, culminating in 2 with submicromolar potency in a HWB assay and efficacy in a CIA mouse model.
Subject(s)
I-kappa B Kinase/antagonists & inhibitors , Protein Kinase Inhibitors/chemistry , Quinolines/chemistry , Semicarbazides/chemistry , Thiourea/analogs & derivatives , Animals , Dogs , Female , Hepatocytes/metabolism , High-Throughput Screening Assays , Humans , I-kappa B Kinase/metabolism , Macaca mulatta , Male , Mice , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/pharmacokinetics , Quinolines/chemical synthesis , Quinolines/pharmacokinetics , Rats , Semicarbazides/chemical synthesis , Semicarbazides/pharmacokinetics , Structure-Activity Relationship , Thiourea/chemical synthesis , Thiourea/chemistry , Thiourea/pharmacokineticsABSTRACT
A novel series of (E)-1-((2-(1-methyl-1H-imidazol-5-yl) quinolin-4-yl) methylene) thiosemicarbazides was discovered as potent inhibitors of IKKß. In this Letter we document our early efforts at optimization of the quinoline core, the imidazole and the semithiocarbazone moiety. Most potency gains came from substitution around the 6- and 7-positions of the quinoline ring. Replacement of the semithiocarbazone with a semicarbazone decreased potency but led to some measurable exposure.
Subject(s)
I-kappa B Kinase/antagonists & inhibitors , Protein Kinase Inhibitors/chemistry , Semicarbazides/chemistry , Animals , Dogs , Female , High-Throughput Screening Assays , I-kappa B Kinase/metabolism , Male , Microsomes/metabolism , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/pharmacokinetics , Quinolines/chemistry , Rats , Semicarbazides/chemical synthesis , Semicarbazides/pharmacokinetics , Structure-Activity RelationshipABSTRACT
A novel class of highly selective inhibitors of p38 MAP kinase was discovered from high throughput screening. The synthesis and optimization of a series of 5-amino-N-phenyl-1H-pyrazol-4-yl-3-phenylmethanones is described. An X-ray crystal structure of this series bound in the ATP binding pocket of unphosphorylated p38alpha established the presence of a unique hydrogen bond between the exocyclic amine of the inhibitor and threonine 106 which likely contributes to the selectivity for p38. The crystallographic information was used to optimize the potency and physicochemical properties of the series. The incorporation of the 2,3-dihydroxypropoxy moiety on the pyrazole scaffold resulted in a compound with excellent drug-like properties including high oral bioavailability. These efforts identified 63 (RO3201195) as an orally bioavailable and highly selective inhibitor of p38 which was selected for advancement into Phase I clinical trials.
Subject(s)
Anti-Inflammatory Agents/chemical synthesis , Pyrazoles/chemical synthesis , p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors , Adenosine Triphosphate/chemistry , Administration, Oral , Animals , Anti-Inflammatory Agents/chemistry , Anti-Inflammatory Agents/pharmacology , Arthritis, Experimental/drug therapy , Binding Sites , Biological Availability , Cell Line , Crystallography, X-Ray , Dogs , Female , Haplorhini , Humans , Interleukin-1/antagonists & inhibitors , Interleukin-1/biosynthesis , Interleukin-6/antagonists & inhibitors , Interleukin-6/biosynthesis , Models, Molecular , Pyrazoles/chemistry , Pyrazoles/pharmacology , Rats , Rats, Inbred Lew , Stereoisomerism , Structure-Activity Relationship , Tumor Necrosis Factor-alpha/antagonists & inhibitors , p38 Mitogen-Activated Protein Kinases/chemistryABSTRACT
A computer-based method was developed for rapid and automatic identification of potential "frequent hitters". These compounds show up as hits in many different biological assays covering a wide range of targets. A scoring scheme was elaborated from substructure analysis, multivariate linear and nonlinear statistical methods applied to several sets of one and two-dimensional molecular descriptors. The final model is based on a three-layered neural network, yielding a predictive Matthews correlation coefficient of 0.81. This system was able to correctly classify 90% of the test set molecules in a 10-times cross-validation study. The method was applied to database filtering, yielding between 8% (compilation of trade drugs) and 35% (Available Chemicals Directory) potential frequent hitters. This filter will be a valuable tool for the prioritization of compounds from large databases, for compound purchase and biological testing, and for building new virtual libraries.
