ABSTRACT
The discovery, synthesis, and characterization of 9H-carbazole-1-carboxamides as potent and selective ATP-competitive inhibitors of Janus kinase 2 (JAK2) are discussed. Optimization for JAK family selectivity led to compounds 14 and 21, with greater than 45-fold selectivity for JAK2 over all other members of the JAK kinase family.
Subject(s)
Amides/chemistry , Janus Kinase 2/antagonists & inhibitors , Protein Kinase Inhibitors/chemistry , Amides/metabolism , Amides/pharmacology , Binding Sites , Carbazoles/chemistry , Cell Line, Tumor , Cell Proliferation/drug effects , Crystallography, X-Ray , Humans , Janus Kinase 1/antagonists & inhibitors , Janus Kinase 1/metabolism , Janus Kinase 2/metabolism , Janus Kinase 3/antagonists & inhibitors , Janus Kinase 3/metabolism , Molecular Dynamics Simulation , Protein Binding , Protein Kinase Inhibitors/metabolism , Protein Kinase Inhibitors/pharmacology , Protein Structure, Tertiary , Structure-Activity RelationshipABSTRACT
Tau-tubulin kinase 1 (TTBK1) is a dual-specificity (serine/threonine and tyrosine) kinase belonging to the casein kinase 1 superfamily. TTBK1 is a neuron-specific kinase that regulates tau phosphorylation. Hyperphosphorylation of tau is implicated in the pathogenesis of Alzheimer's disease. Two kinase-domain constructs of TTBK1 were expressed in a baculovirus-infected insect-cell system and purified. The purified TTBK1 kinase-domain proteins were crystallized using the hanging-drop vapor-diffusion method. X-ray diffraction data were collected and the structure of TTBK1 was determined by molecular replacement both as an apo structure and in complex with a kinase inhibitor.
Subject(s)
Protein Kinase Inhibitors/chemistry , Protein Serine-Threonine Kinases/chemistry , Animals , Baculoviridae/genetics , Crystallization , Crystallography, X-Ray , Electrophoresis, Polyacrylamide Gel , Humans , Magnetic Resonance Spectroscopy , Protein Conformation , Sf9 Cells , Substrate SpecificityABSTRACT
SAR studies of pyrrolo[1,2-f]triazines as JAK2 inhibitors is presented. Achieving JAK2 inhibition selectively over JAK3 is discussed.
Subject(s)
Enzyme Activation/drug effects , Enzyme Inhibitors/pharmacology , Janus Kinase 2/metabolism , Janus Kinase 3/metabolism , Pyrrolidines/chemical synthesis , Triazines/chemical synthesis , Triazines/pharmacology , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , Janus Kinase 2/antagonists & inhibitors , Models, Molecular , Molecular Structure , Protein Binding , Pyrroles/chemical synthesis , Pyrroles/chemistry , Pyrroles/pharmacology , Pyrrolidines/chemistry , Pyrrolidines/pharmacology , Structure-Activity Relationship , Triazines/chemistryABSTRACT
A novel series of 5-((4-aminopiperidin-1-yl)methyl)-pyrrolo[2,1-f][1,2,4]triazin-4-amines with small aniline substituents at the C4 position were optimized for dual EGFR and HER2 protein tyrosine kinase inhibition. Compound 8l exhibited promising oral efficacy in both EGFR and HER2-driven human tumor xenograft models.
Subject(s)
Antineoplastic Agents/chemistry , Antineoplastic Agents/therapeutic use , ErbB Receptors/antagonists & inhibitors , Neoplasms/drug therapy , Protein-Tyrosine Kinases/chemistry , Protein-Tyrosine Kinases/therapeutic use , Receptor, ErbB-2/antagonists & inhibitors , Animals , Antineoplastic Agents/pharmacokinetics , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Colonic Neoplasms/drug therapy , ErbB Receptors/metabolism , Humans , Male , Mice , Mice, Inbred BALB C , Models, Molecular , Neoplasms/enzymology , Protein-Tyrosine Kinases/pharmacokinetics , Protein-Tyrosine Kinases/pharmacology , Pyrroles/chemistry , Pyrroles/pharmacokinetics , Pyrroles/pharmacology , Pyrroles/therapeutic use , Receptor, ErbB-2/metabolism , Stomach Neoplasms/drug therapy , Triazines/chemistry , Triazines/pharmacokinetics , Triazines/pharmacology , Triazines/therapeutic use , Xenograft Model Antitumor AssaysABSTRACT
Structure-activity relationships in a series of 4-[1H-indazol-5-ylamino]pyrrolo[2,1-f][1,2,4]triazine-6-carbamates identified dual human epidermal growth factor receptor (HER)1/HER2 kinase inhibitors with excellent biochemical potency and kinase selectivity. On the basis of its favorable pharmacokinetic profile and robust in vivo activity in HER1 and HER2 driven tumor models, 13 (BMS-599626) was selected as a clinical candidate for treatment of solid tumors.
Subject(s)
Antineoplastic Agents/chemical synthesis , Carbamates/chemical synthesis , ErbB Receptors/antagonists & inhibitors , Receptor, ErbB-2/antagonists & inhibitors , Triazines/chemical synthesis , Administration, Oral , Animals , Antineoplastic Agents/pharmacokinetics , Antineoplastic Agents/pharmacology , Biological Availability , Carbamates/pharmacokinetics , Carbamates/pharmacology , Cell Line, Tumor , Dogs , Drug Screening Assays, Antitumor , Humans , Macaca fascicularis , Mice , Neoplasm Transplantation , Stereoisomerism , Structure-Activity Relationship , Transplantation, Heterologous , Triazines/pharmacokinetics , Triazines/pharmacologyABSTRACT
This report describes the biological activity, characterization, and SAR leading to 9d (BMS-754807) a small molecule IGF-1R kinase inhibitor in clinical development.
Subject(s)
Biomedical Research , Protein Kinase Inhibitors/pharmacology , Pyrazoles/pharmacology , Receptor, IGF Type 1/antagonists & inhibitors , Triazines/pharmacology , Animals , Dogs , Drug Discovery , Humans , Mice , Models, Molecular , Molecular Conformation , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacokinetics , Protein Kinase Inhibitors/therapeutic use , Pyrazoles/chemistry , Pyrazoles/pharmacokinetics , Pyrazoles/therapeutic use , Rats , Receptor, IGF Type 1/chemistry , Structure-Activity Relationship , Triazines/chemistry , Triazines/pharmacokinetics , Triazines/therapeutic useABSTRACT
Pyrrolotriazine dual EGFR/HER2 kinase inhibitors with a 5-((4-aminopiperidin-1-yl)methyl) solubilizing group were found to be superior to analogs with previously reported C-5 solubilizing groups. New synthetic methodology was developed for the parallel synthesis of C-4 analogs with the new solubilizing group. Interesting new leads were evaluated in tumor xenograft models and the C-4 aminofluorobenzylindazole, 1c, was found to exhibit the best antitumor activity. It is hypothesized that this solubilizing group extends into the ribose-phosphate portion of the ATP binding pocket and enhances the binding affinity of the inhibitor.
Subject(s)
Chemistry, Pharmaceutical/methods , ErbB Receptors/chemistry , Neoplasms/drug therapy , Piperidines/chemical synthesis , Pyrroles/chemical synthesis , Receptor, ErbB-2/chemistry , Triazines/chemical synthesis , Adenosine Triphosphate/metabolism , Animals , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Drug Design , Drug Screening Assays, Antitumor , Humans , Inhibitory Concentration 50 , Insecta , Models, Chemical , Neoplasm Transplantation , Piperidines/chemistry , Piperidines/pharmacology , Pyrroles/chemistry , Pyrroles/pharmacology , Triazines/chemistry , Triazines/pharmacologyABSTRACT
Novel C-5 aminomethyl pyrrolotriazines were prepared and optimized for dual EGFR and HER2 protein tyrosine kinase inhibition. The homopiperazine, 1p, emerged as a key lead and it showed promising oral efficacy in EGFR and dual EGFR/HER2 driven human tumor xenograft models. It is hypothesized that the C-5 homopiperazine side chain binds in the ribose-phosphate portion of the ATP binding pocket.
Subject(s)
Antineoplastic Agents/pharmacology , ErbB Receptors/antagonists & inhibitors , Methylamines/pharmacology , Protein-Tyrosine Kinases/antagonists & inhibitors , Pyrroles/pharmacology , Receptor, ErbB-2/antagonists & inhibitors , Triazines/pharmacology , Animals , Cell Line, Tumor , Disease Models, Animal , Drug Screening Assays, Antitumor , Humans , Methylamines/chemistry , Mice , Models, Molecular , Molecular Structure , Neoplasm Transplantation , Pyrroles/chemistry , Structure-Activity Relationship , Triazines/chemistry , Xenograft Model Antitumor AssaysABSTRACT
Novel C-5 substituted pyrrolotriazines were optimized for dual EGFR and HER2 protein tyrosine kinase inhibition. The lead compound exhibited promising oral efficacy in both EGFR and HER2 driven human tumor xenograft models. It is hypothesized that its C-5 morpholine side chain binds in the ribose phosphate portion of the ATP binding pocket.
Subject(s)
Chemistry, Pharmaceutical/methods , ErbB Receptors/antagonists & inhibitors , Pyrroles/chemical synthesis , Receptor, ErbB-2/antagonists & inhibitors , Triazines/chemical synthesis , Adenosine Triphosphate/chemistry , Animals , Caco-2 Cells , Drug Design , Enzyme Inhibitors/pharmacology , Humans , Inhibitory Concentration 50 , Mice , Neoplasm Transplantation , Phosphates/chemistry , Pyrroles/pharmacology , Ribose/chemistry , Triazines/pharmacologyABSTRACT
PURPOSE: The studies described here are intended to characterize the ability of BMS-599626, a small-molecule inhibitor of the human epidermal growth factor receptor (HER) kinase family, to modulate signaling and growth of tumor cells that depend on HER1 and/or HER2. EXPERIMENTAL DESIGN: The potency and selectivity of BMS-599626 were assessed in biochemical assays using recombinant protein kinases, as well as in cell proliferation assays using tumor cell lines with varying degrees of dependence on HER1 or HER2 signaling. Modulation of receptor signaling was determined in cell assays by Western blot analyses of receptor autophosphorylation and downstream signaling. The ability of BMS-599626 to inhibit receptor heterodimer signaling in tumor cells was studied by receptor coimmunoprecipitation. Antitumor activity of BMS-599626 was evaluated using a number of different xenograft models that represent a spectrum of human tumors with HER1 or HER2 overexpression. RESULTS: BMS-599626 inhibited HER1 and HER2 with IC50 of 20 and 30 nmol/L, respectively, and was highly selective when tested against a broad panel of diverse protein kinases. Biochemical studies suggested that BMS-599626 inhibited HER1 and HER2 through distinct mechanisms. BMS-599626 abrogated HER1 and HER2 signaling and inhibited the proliferation of tumor cell lines that are dependent on these receptors, with IC50 in the range of 0.24 to 1 micromol/L. BMS-599626 was highly selective for tumor cells that depend on HER1/HER2 and had no effect on the proliferation of cell lines that do not express these receptors. In tumor cells that are capable of forming HER1/HER2 heterodimers, BMS-599626 inhibited heterodimerization and downstream signaling. BMS-599626 had antitumor activity in models that overexpress HER1 (GEO), as well as in models that have HER2 gene amplification (KPL4) or overexpression (Sal2), and there was good correlation between the inhibition of receptor signaling and antitumor activity. CONCLUSIONS: BMS-599626 is a highly selective and potent inhibitor of HER1 and HER2 kinases and inhibits tumor cell proliferation through modulation of receptor signaling. BMS-599626 inhibits HER1/HER2 receptor heterodimerization and provides an additional mechanism of inhibiting tumors in which receptor coexpression and heterodimerization play a major role in driving tumor growth. The preclinical data support the advancement of BMS-599626 into clinical development for the treatment of cancer.
Subject(s)
Antineoplastic Agents/toxicity , Enzyme Inhibitors/toxicity , ErbB Receptors/antagonists & inhibitors , Receptor, ErbB-2/antagonists & inhibitors , Antibodies, Monoclonal/pharmacology , CD8 Antigens/immunology , Cell Division/drug effects , Cell Line , Cell Line, Tumor , Dimerization , HumansABSTRACT
A novel series of dual EGFR and HER2 inhibitors based on the pyrrolo[2,1-f][1,2,4]triazine nucleus is described. A general route toward their synthesis, which enables functionalization at multiple sites, has been developed. Biological evaluation in enzymatic and cell-based assays has identified a series of C-6 carbamates with potent biochemical and cellular activities.
Subject(s)
ErbB Receptors/antagonists & inhibitors , Receptor Protein-Tyrosine Kinases/antagonists & inhibitors , Receptor, ErbB-2/antagonists & inhibitors , Binding Sites , Carbamates/chemical synthesis , Carbamates/pharmacology , Cell Line, Tumor , Cell Proliferation/drug effects , Humans , Models, Molecular , Structure-Activity Relationship , Triazines/chemical synthesis , Triazines/pharmacologyABSTRACT
The evolution of 2, a C-4-methylcarbonate analogue of paclitaxel with minimal oral bioavailability and oral efficacy, into its C-3'-t-butyl-3'-N-t-butyloxycarbonyl analogue (15i), a novel taxane with oral efficacy in preclinical models that is comparable to iv administered paclitaxel, is described.
Subject(s)
Bridged-Ring Compounds/pharmacokinetics , Taxoids/pharmacokinetics , Administration, Oral , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacology , Biological Availability , Bridged-Ring Compounds/chemistry , Bridged-Ring Compounds/pharmacology , Cell Line, Tumor , Cell Survival/drug effects , Drug Evaluation, Preclinical , Humans , Inhibitory Concentration 50 , Mice , Rats , Structure-Activity Relationship , Taxoids/chemistry , Taxoids/pharmacologyABSTRACT
High mole ratio BR96 immunoconjugates were synthesized using branched peptide-doxorubicin linkers designed to liberate doxorubicin following antigen-specific internalization into lysosomes. However, these immunoconjugates are highly prone to noncovalent, dimeric aggregation. We hypothesize that this is due to (1) the hydrophobic nature of the peptides, (2) the loss of positive charge upon amide formation at the 3'-amino group of doxorubicin, and (3) the proximity of the peptide hydrophobic residues to form efficient intermolecular stacking interactions. By introducing a hydrophilic methoxytriethylene glycol chain onto the doxorubicin portion of the branched peptide linkers, aggregation has been eliminated or greatly reduced in the immunoconjugate products. The methoxytriethylene glycol chain was linked to the doxorubicin moiety of the linker via a hydrazone bond that is stable at pH 7 but hydrolyzes rapidly at pH 5 to release free drug. BR96 immunoconjugates synthesized from methoxytriethylene glycol-modified branched peptide-doxorubicin linkers are highly potent and immunospecific in vitro. The data suggest that the methoxytriethylene glycol chain hydrolyzes as designed upon antigen-specific internalization into tumor lysosomes in vitro, where enzymatic degradation of the peptide linker releases free doxorubicin.
Subject(s)
Antibodies, Monoclonal/chemistry , Antineoplastic Agents/chemistry , Dipeptides/chemistry , Doxorubicin/chemistry , Immunoconjugates/chemistry , Antibodies, Monoclonal/pharmacology , Antineoplastic Agents/pharmacology , Dimerization , Doxorubicin/analogs & derivatives , Doxorubicin/pharmacology , Humans , Hydrogen-Ion Concentration , Hydrolysis , Inhibitory Concentration 50 , Tumor Cells, CulturedABSTRACT
Bivalent doxorubicin (DOX)-dipeptides (16a-c) were prepared and conjugated to the monoclonal antibody BR96. The dipeptides are cleaved by lysosomal proteases following internalization of the resulting immunoconjugates. Conjugate 18b demonstrated antigen-specific in vitro tumor cell killing activity (IC(50)=0.2 microM) that was equipotent to DOX with a near doubling of drug molecules/MAb. Size exclusion chromatography showed 18b to be a noncovalent dimer that was formed immediately upon conjugation.
