thiopental-sodium and Lung-Neoplasms

The epidermal growth factor receptor (EGFR) has been a particular interest for drug development for treatment of non-small-cell lung cancer (NSCLC). The current third-generation EGFR small-molecule inhibitors, especially osimertinib, are at the forefront clinically for treatment of patients with NSCLC. However, a high percentage of these treated patients developed a tertiary cystein-797 to serine-790 (C797S) mutation in the EGFR kinase domain. This C797S mutation is thought to induce resistance to all current irreversible EGFR TKIs. In this Miniperspective, we present key mechanisms of resistance in response to third-generation EGFR TKIs, and emerging reports on novel EGFR TKIs to combat the resistance. Specifically, we analyze the allosteric and ATP-competitive inhibitors in terms of drug discovery, binding mechanism, and their potency and selectivity against EGFR harboring C797S mutations. Lastly, we provide some perspectives on new challenges and future directions in this field.

Topics: Carcinoma, Non-Small-Cell Lung; Drug Resistance, Neoplasm; ErbB Receptors; Humans; Lung Neoplasms; Molecular Targeted Therapy; Mutation; Protein Kinase Inhibitors

On the basis of Ibrutinib's core pharmacophore, which was moderately active to EGFR T790M mutant, we discovered novel epidermal growth factor receptor (EGFR) inhibitor compound 19 (CHMFL-EGFR-202), which potently inhibited EGFR primary mutants (L858R, del19) and drug-resistant mutant L858R/T790M. Compound 19 displayed a good selectivity profile among 468 kinases/mutants tested in the KINOMEscan assay (S score (1) = 0.02). In particular, it did not exhibit apparent activities against INSR and IGF1R kinases. The X-ray crystal structure revealed that this class of inhibitors formed a covalent bond with Cys797 in a distinct "DFG-in-C-helix-out" inactive EGFR conformation. Compound 19 displayed strong antiproliferative effects against EGFR mutant-driven nonsmall cell lung cancer (NSCLC) cell lines such as H1975, PC9, HCC827, and H3255 but not the wild-type EGFR expressing cells. In the H1975 and PC9 cell-inoculated xenograft mouse models, compound 19 exhibited dose-dependent tumor growth suppression efficacy without obvious toxicity. Compound 19 might be a potential drug candidate for EGFR mutant-driven NSCLC.

Topics: Animals; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Proliferation; Crystallography, X-Ray; ErbB Receptors; Female; Humans; Lung; Lung Neoplasms; Mice; Mice, Nude; Molecular Docking Simulation; Piperidines; Point Mutation; Protein Conformation; Protein Kinase Inhibitors; Rats, Sprague-Dawley

Topics: A549 Cells; Antineoplastic Agents; Binding Sites; Carcinoma, Non-Small-Cell Lung; Cell Proliferation; Drug Design; Drug Resistance, Neoplasm; ErbB Receptors; Gefitinib; HT29 Cells; Humans; Lung Neoplasms; Molecular Docking Simulation; Protein Binding; Protein Kinase Inhibitors; Protein Structure, Tertiary; Quinazolines; Structure-Activity Relationship

Inhibition of the epidermal growth factor receptor represents one of the most promising strategies in the treatment of lung cancer. Acquired resistance compromises the clinical efficacy of EGFR inhibitors during long-term treatment. The recently discovered EGFR-C797S mutation causes resistance against third-generation EGFR inhibitors. Here we present a rational approach based on extending the inhibition profile of a p38 MAP kinase inhibitor toward mutant EGFR inhibition. We used a privileged scaffold with proven cellular potency as well as in vivo efficacy and low toxicity. Guided by molecular modeling, we synthesized and studied the structure-activity relationship of 40 compounds against clinically relevant EGFR mutants. We successfully improved the cellular EGFR inhibition down to the low nanomolar range with covalently binding inhibitors against a gefitinib resistant T790M mutant cell line. We identified additional noncovalent interactions, which allowed us to develop metabolically stable inhibitors with high activities against the osimertinib resistant L858R/T790M/C797S mutant.

Topics: Antineoplastic Agents; Cell Line, Tumor; Drug Resistance, Neoplasm; ErbB Receptors; Gefitinib; Humans; Imidazoles; Lung Neoplasms; Molecular Docking Simulation; Point Mutation; Protein Kinase Inhibitors; Quinazolines; Structure-Activity Relationship

Recently, more and more concomitant EGFR mutations and ALK rearrangement are observed from the clinic, which still lacks effective single-agent therapy. Starting from ALK inhibitor 14 (TAE684), we have developed a highly potent EGFR/ALK dual kinase inhibitor compound 18 (CHMFL-ALK/EGFR-050), which potently inhibited EGFR L858R, del 19 and T790M mutants as well as EML4-ALK, R1275Q, L1196M, F1174L and C1156Y mutants biochemically. Compound 18 significantly inhibited the proliferation of EGFR mutant and EML4-ALK driven NSCLC cell lines. In the cellular context it strongly affected EGFR and ALK mediated signaling pathways, induced apoptosis and arrested cell cycle at G0/G1 phase. In the in vivo studies, 18 significantly suppressed the tumor growth in H1975 cell inoculated xenograft model (40 mg/kg/d, TGI: 99%) and H3122 cell inoculated xenograft model (40 mg/kg/d, TGI: 78%). Compound 18 might be a potential drug candidate for EGFR- or ALK-individual as well as concomitant EGFR/ALK NSCLC.

Topics: Acrylamides; Anaplastic Lymphoma Kinase; Animals; Apoptosis; Carcinoma, Non-Small-Cell Lung; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Dose-Response Relationship, Drug; Drug Discovery; Drug Resistance, Neoplasm; Drug Screening Assays, Antitumor; ErbB Receptors; Female; Humans; Lung Neoplasms; Mice; Mice, Nude; Molecular Structure; Neoplasms, Experimental; Protein Kinase Inhibitors; Pyrimidines; Receptor Protein-Tyrosine Kinases; Structure-Activity Relationship

Reversible epidermal growth factor receptor (EGFR) inhibitors prompt a beneficial clinical response in non-small cell lung cancer patients who harbor activating mutations in EGFR. However, resistance mutations, particularly the gatekeeper mutation T790M, limit this efficacy. Here, we describe a structure-guided development of a series of covalent and mutant-selective EGFR inhibitors that effectively target the T790M mutant. The pyrazolopyrimidine-based core differs structurally from that of aminopyrimidine-based third-generation EGFR inhibitors and therefore constitutes a new set of inhibitors that target this mechanism of drug resistance. These inhibitors exhibited strong inhibitory effects toward EGFR kinase activity and excellent inhibition of cell growth in the drug-resistant cell line H1975, without significantly affecting EGFR wild-type cell lines. Additionally, we present the in vitro ADME/DMPK parameters for a subset of the inhibitors as well as in vivo pharmacokinetics in mice for a candidate with promising activity profile.

Topics: Animals; Antineoplastic Agents; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Drug Resistance, Neoplasm; ErbB Receptors; Humans; Lung Neoplasms; Male; Mice; Molecular Docking Simulation; Point Mutation; Protein Kinase Inhibitors; Pyrazoles; Pyrimidines

Because of the development of drug-resistance mutations, particularly the "gatekeeper" threonine(790)-to-methionine(790) (T790M) mutation in the ATP-binding pocket of the epidermal growth factor receptor (EGFR), the current generation of EGFR tyrosine kinase inhibitors lost their clinical efficacy. Recently, a large number of small-molecule inhibitors with striking inhibitory potency against EGFR mutants with the T790M change have been identified. In particular, the inhibitors rociletinib and osimertinib, which can selectively target both sensitizing mutations and the T790M resistance while sparing the wild-type (WT) form of the receptor, have been designated as breakthrough therapies in the treatment of mutant non-small-cell lung cancer (NSCLC) by the U.S. FDA in 2014. We hope that this review on the small-molecule EGFR T790M inhibitors, along with their discovery strategies, will assist in the design of future T790M-containing EGFR inhibitors with high levels of selectivity over WT EGFR, broad kinase selectivity, and desirable physicochemical properties.

Topics: Animals; Antineoplastic Agents; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Proliferation; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; ErbB Receptors; Humans; Lung Neoplasms; Mice; Models, Molecular; Molecular Structure; Neoplasms, Experimental; Protein Kinase Inhibitors; Pyridones; Small Molecule Libraries; Structure-Activity Relationship

To overcome the drug-resistance of first generation EGFR inhibitors and the nonselective toxicities of second generation inhibitors among NSCLC patients, a series of 5-(methylthio)pyrimidine derivatives were discovered as novel EGFR inhibitors, which harbored not only potent enzymatic and antiproliferative activities against EGFR(L858R/T790M) mutants, but good selectivity over wide-type form of the receptor. This goal was achieved by employing structure-based drug design and traditional optimization strategies, based on WZ4002 and CO1686. These derivatives inhibited the enzymatic activity of EGFR(L858R/T790M) mutants with IC50 values in subnanomolar ranges, while exhibiting hundreds of fold less potency on EGFR(WT). These compounds also strongly inhibited the proliferation of H1975 non-small cell lung cancer cells bearing EGFR(L858R/T790M), while being significantly less toxic to A431 human epithelial carcinoma cells with overexpressed EGFR(WT). The EGFR kinase inhibitory and antiproliferative activities were further validated by Western blot analysis for activation of EGFR and the downstream signaling in cancer cells.

Topics: Antineoplastic Agents; Carcinoma, Non-Small-Cell Lung; Cell Proliferation; Drug Screening Assays, Antitumor; ErbB Receptors; Humans; Lung Neoplasms; Methylation; Molecular Docking Simulation; Point Mutation; Protein Kinase Inhibitors; Pyrimidines

The clinical success of covalent kinase inhibitors in the treatment of EGFR-dependent non-small cell lung cancer (NSCLC) has rejuvenated the appreciation of reactive small molecules. Acquired drug resistance against first-line EGFR inhibitors remains the major bottleneck in NSCLC and is currently addressed by the application of fine-tuned covalent drugs. Here we report the design, synthesis and biochemical evaluation of a novel class of EGFR inhibitors with a covalent yet reversible warhead. A series of WZ4002 analogs, derived from anilinopyrimidine and 3-substituted-2-cyanoacrylamide scaffolds, exhibit strong and selective inhibitory activity against clinically relevant EGFR(L858R) and EGFR(L858R/T790M).

Topics: Acrylamides; Animals; Carcinoma, Non-Small-Cell Lung; Cell Line; Drug Design; Drug Resistance, Neoplasm; ErbB Receptors; Humans; Lung Neoplasms; Models, Molecular; Mutation; Point Mutation; Protein Kinase Inhibitors; Pyrimidines

Receptor tyrosine kinases represent one of the prime targets in cancer therapy, as the dysregulation of these elementary transducers of extracellular signals, like the epidermal growth factor receptor (EGFR), contributes to the onset of cancer, such as non-small cell lung cancer (NSCLC). Strong efforts were directed to the development of irreversible inhibitors and led to compound CO-1686, which takes advantage of increased residence time at EGFR by alkylating Cys797 and thereby preventing toxic effects. Here, we present a structure-based approach, rationalized by subsequent computational analysis of conformational ligand ensembles in solution, to design novel and irreversible EGFR inhibitors based on a screening hit that was identified in a phenotype screen of 80 NSCLC cell lines against approximately 1500 compounds. Using protein X-ray crystallography, we deciphered the binding mode in engineered cSrc (T338M/S345C), a validated model system for EGFR-T790M, which constituted the basis for further rational design approaches. Chemical synthesis led to further compound collections that revealed increased biochemical potency and, in part, selectivity toward mutated (L858R and L858R/T790M) vs nonmutated EGFR. Further cell-based and kinetic studies were performed to substantiate our initial findings. Utilizing proteolytic digestion and nano-LC-MS/MS analysis, we confirmed the alkylation of Cys797.

Topics: Antineoplastic Agents; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Membrane Permeability; Crystallography, X-Ray; Databases, Chemical; Drug Design; Drug Resistance, Neoplasm; ErbB Receptors; Humans; Kinetics; Lung Neoplasms; Models, Molecular; Molecular Conformation; Mutation; Pyrazoles; Pyrimidines; Quinazolines; Small Molecule Libraries; Solubility; src-Family Kinases; Structure-Activity Relationship

A series of hybrids (12a-k) from (phenylsulfonyl)furoxan and anilinopyrimidine were synthesized and biologically evaluated as epidermal growth factor receptor (EGFR) inhibitors for intervention of non-small-cell lung cancer (NSCLC). Compound 12k exhibited strong and selective EGFR L858R/T790M inhibitory activity (IC50 = 0.047 μM) and displayed antiproliferative effects on EGFR mutation NSCLC cell lines HCC827 (del E746_A750) and H1975 (L858R/T790M) with IC50 values of 0.007 and 0.029 μM, respectively. Additionally, 12k released high levels of NO in H1975 cells but not in normal human cells, and its activity was diminished by pretreatment with a NO scavenger. Furthermore, 12k induced apoptosis of H1975 and HCC827 cells more strongly than WZ4002 (1), inhibited EGFR downstream signaling in H1975 cells, and suppressed the nuclear factor-κB activation in H1975 cells, while 1 had no significant effects under the same conditions. Finally, 12k substantially inhibited tumor growth in an H1975 xenograft mouse model. Overall, 12k might be a promising candidate for the treatment of NSCLC.

Topics: Aniline Compounds; Animals; Antineoplastic Agents; Apoptosis; Carcinoma, Non-Small-Cell Lung; Cell Line; Cell Line, Tumor; Drug Screening Assays, Antitumor; Enzyme Activation; ErbB Receptors; Humans; Lung Neoplasms; Male; Mice; Mice, Nude; Neoplasm Transplantation; NF-kappa B; Nitric Oxide; Oxadiazoles; Pyrimidines; Signal Transduction; Transplantation, Heterologous

The EGFR T790M variant is an important mutation, resulting in approximately 50% of the clinically acquired resistance to approved EGFR inhibitors. Starting with a previously reported pyrimidine-based EGFR inhibitor, a novel pteridin-7(8H)-one scaffold with a high 3D similarity was found and transformed into irreversible inhibitors of the EGFR T790M mutant. The most potent compounds, 3q and 3x, exhibited excellent enzyme inhibitory activities, with subnanomolar IC50 values for both the wild-type and T790M/L858R double mutant EGFRs, as well as potent cellular antiproliferative activities against both gefitinib-sensitive and -resistant cancer cell lines. The in vivo antitumor efficacy study demonstrated that compound 3x significantly inhibited tumor growth and induced tumor stasis in an EGFR-T790M/L858R-driven human nonsmall-cell lung cancer xenograft mouse model. This work demonstrated the utility of this sophisticated computational design strategy for fast 3D scaffold hopping with competitive bioactivities to meet an important clinical need.

Topics: Animals; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Proliferation; Computational Biology; Drug Discovery; Drug Resistance, Neoplasm; ErbB Receptors; Gefitinib; Humans; Lung Neoplasms; Mice; Mice, Nude; Mice, SCID; Models, Chemical; Molecular Structure; Mutation; Protein Kinase Inhibitors; Pteridines; Quinazolines; Xenograft Model Antitumor Assays

The EGFR(T790M) mutant contributes approximately 50% to clinically acquired resistance against gefitinib or erlotinib. However, almost all the single agent clinical trials of the second generation irreversible EGFR inhibitors appear inadequate to overcome the EGFR(T790M)-related resistance. We have designed and synthesized a series of 2-oxo-3,4-dihydropyrimido[4,5-d]pyrimidinyl derivatives as novel EGFR inhibitors. The most potent compounds, 2q and 2s, inhibited the enzymatic activities of wild-type and mutated EGFRs, with IC(50) values in subnanomolar ranges, including the T790M mutants. The kinase inhibitory efficiencies of the compounds were further validated by Western blot analysis of the activation of EGFR and downstream signaling in cancer cells harboring different mutants of EGFR. The compounds also strongly inhibited the proliferation of H1975 non small cell lung cancer cells bearing EGFR(L858R/T790M), while being significantly less toxic to normal cells. Moreover, 2s displayed promising anticancer efficacy in a human NSCLC (H1975) xenograft nude mouse model.

Topics: Animals; Antineoplastic Agents; Carcinoma, Non-Small-Cell Lung; Cell Proliferation; Drug Design; Drug Resistance, Neoplasm; Drug Screening Assays, Antitumor; ErbB Receptors; Erlotinib Hydrochloride; Gefitinib; Humans; Lung Neoplasms; Methionine; Mice; Mice, Nude; Mice, SCID; Molecular Conformation; Mutation; Neoplasm Transplantation; Pyrimidines; Quinazolines; Structure-Activity Relationship; Threonine; Transplantation, Heterologous