Design, Synthesis and Antitumor Activity of Novel Selenium-Containing Tepotinib Derivatives as Dual Inhibitors of c-Met and TrxR.

Cellular mesenchymal-epithelial transition factor (c-Met), an oncogenic transmembrane receptor tyrosine kinase (RTK), plays an essential role in cell proliferation during embryo development and liver regeneration. Thioredoxin reductase (TrxR) is overexpressed and constitutively active in most tumors closely related to cancer recurrence. Multi-target-directed ligands (MTDLs) strategy provides a logical approach to drug combinations and would adequately address the pathological complexity of cancer. In this work, we designed and synthesized a series of selenium-containing tepotinib derivatives by means of selenium-based bioisosteric modifications and evaluated their antiproliferative activity. Most of these selenium-containing hybrids exhibited potent dual inhibitory activity toward c-Met and TrxR. Among them, compound 8b was the most active, with an IC50 value of 10 nM against MHCC97H cells. Studies on the mechanism of action revealed that compound 8b triggered cell cycle arrest at the G1 phase and caused ROS accumulations by targeting TrxR, and these effects eventually led to cell apoptosis. These findings strongly suggest that compound 8b serves as a dual inhibitor of c-Met and TrxR, warranting further exploitation for cancer therapy.

Phase Ia/Ib Study of the Selective MET Inhibitor, Savolitinib, in Patients with Advanced Solid Tumors: Safety, Efficacy, and Biomarkers.

BACKGROUND: Savolitinib has shown good tolerability and preliminary efficacy, but efficacy biomarkers require investigation. The main purpose of this study was to confirm in Chinese patients the recommended phase II dose (RP2D) of savolitinib and to explore overall benefit in tumors bearing c-Met aberration. METHODS: This was an open-label, multi-center, 2-part phase I study. A starting dose of 600 mg QD was initiated in the escalation phase, utilizing a 3+3 design with repeated QD and BID dosing. In the dose expansion phase, we enrolled patients with gastric cancer and non-small cell lung cancer (NSCLC) with documented c-met aberration into 5 cohorts to further explore biomarkers. c-Met overexpression and amplification were assessed by immunohistochemistry and FISH, respectively. RESULTS: The safety analysis set included 85 patients. Only one dose-limiting toxicity (grade 3 fatigue) was reported in the 600 mg BID dosing group. The most frequent treatment-related adverse events were nausea (29.4%), vomiting (27.1%), and peripheral edema (21.2%). Notably, in gastric cancer, response was only observed in patients with MET amplification (copy number 9.7-18.4), with an objective response rate of 35.7% and a disease control rate of 64.3%. For patients with NSCLC bearing a MET exon 14 skipping mutation, obvious target lesion shrinkage was observed in 2 of 4 patients, although PR was not achieved. CONCLUSION: The RP2D of savolitinib was established as 600 mg QD or 500 mg BID in Chinese patients. The promising response observed in patients with gastric cancer with c-met amplification and NSCLC with MET exon 14 skipping mutation warrants further investigation. CLINICALTRIALS.GOV IDENTIFIER: NCT0198555.

Novel 4-phenoxypyridine derivatives bearing imidazole-4-carboxamide and 1,2,4-triazole-3-carboxamide moieties: Design, synthesis and biological evaluation as potent antitumor agents.

Two series of novel 4-phenoxypyridine derivatives containing imidazole-4-carboxamide and 4-methyl-5-oxo-4,5-dihydro-1,2,4-triazole-3-carboxamide moieties were synthesized and evaluated for their in vitro inhibitory activities against c-Met kinase and antiproliferative activities against MKN-45, A549 and H460 cancer cell lines. The results indicated that most of the compounds showed moderate to good antitumor activities. The most promising compound T14 (with c-Met IC50 value of 0.012 µM) showed remarkable antiproliferative activities against MKN-45, A549 and H460 cell lines with IC50 values of 0.64 µM, 1.92 µM and 2.68 µM, respectively. Their preliminary structure-activity relationships (SARs) studies indicate that imidazole-4-carboxamide was more preferred as linker part, and electron-withdrawing groups (especially halogen groups) on the terminal phenyl rings were beneficial for improving the antitumor activities.

Inhibition of c-MET increases the antitumour activity of PARP inhibitors in gastric cancer models.

Gastric cancer is the fifth most common malignancy and the third leading cause of cancer-related death worldwide. Activation of c-MET increases tumour cell survival through the initiation of the DNA damage repair pathway. PARP is an essential key in the DNA damage repair pathway. The primary role of PARP is to detect and initiate an immediate cellular response to single-strand DNA breaks. Tumours suppressor genes such as BRCA1/2 are closely associated with the DNA repair pathway. In BRCA1/2 mutations or deficiency status, cells are more likely to develop additional genetic alterations and chromosomal instability and can lead to cancer. In this study, we investigate the role of c-MET and PARP inhibition in a gastric cancer model. We exploited functional in vitro and in vivo experiments to assess the antitumour potential of co-inhibition of c-MET (SU11274) and PARP (NU1025). This leads to a reduction of gastric cancer cells viability, especially after knockdown of BRCA1/2 through apoptosis and induction of γ-Η2ΑΧ. Moreover, in AGS xenograft models, the combinatorial treatment of NU1025 plus SU11274 reduced tumour growth and triggers apoptosis. Collectively, our data may represent a new therapeutic approach for GC thought co-inhibition of c-MET and PARP, especially for patients with BRCA1/2 deficiency tumours.

Dynasore potentiates c-Met inhibitors against hepatocellular carcinoma through destabilizing c-Met.

c-Met receptor is frequently overexpressed in hepatocellular carcinoma and thus considered as an attractive target for pharmacological intervention with small molecule tyrosine kinase inhibitors. Albeit with the development of multiple c-Met inhibitors, none reached clinical application in the treatment of hepatoma so far. To improve the efficacy of c-Met inhibitors towards hepatocellular carcinoma, we investigated the combined effects of the dynamin inhibitor dynasore with several c-Met inhibitors, including tivantinib, PHA-665752, and JNJ-38877605. We provide several lines of evidence that dynasore enhanced the inhibitory effects of these inhibitors on hepatoma cell proliferation and migration, accompanied with increased cell cycle arrest and apoptosis. Mechanically, the combinatorial treatments decreased c-Met levels and hence markedly disrupted downstream signaling, as revealed by the dramatically declined phosphorylation of AKT and MEK. Taken together, our findings demonstrate that the candidate agent dynasore potentiated the inhibitory effects of c-Met inhibitors against hepatoma cells and will shed light on the development of novel therapeutic strategies to target c-Met in the clinical management of hepatocellular carcinoma patients.

A C-Met chemical inhibitor promotes fracture healing through interacting with osteogenic differentiation via the mTORC1 pathway.

Currently, HGF/C-Met signaling inhibitors are being investigated to determine if they are useful for enhancing progenitor cell differentiation into osteoblasts, and one of them, BMS-777607, has been utilized to treat osteoporosis and bone loss in several types of diseases. However, whether BMS-777607 could be a potential treatment during fracture healing remains elusive. Here, we examined the therapeutic effects of BMS-777607 on bone fracture healing in a mouse model. In vivo radiological analysis showed that fractures treated with BMS-777607 exhibited accelerated osteotylus formation during the early stage of bone healing. Thereafter, the Safranin O staining evaluation indicated that the structure of the external callus in the Treatment group was larger than that in the Vehicle group at week 2. Furthermore, cellular proliferation of MC3T3-E1 was not significantly affected by low concentrations of BMS-777607. In addition, stimulation of osteoblast differentiation and mineralization was a result of BMS-777607 inducing the expression of Runx2 and Col1, and this osteogenic ability, at least in part, was mediated through the mammalian target of rapamycin complex 1 (mTORC1) signaling in vitro. Conclusively, BMS-777607 has been identified as a therapeutic agent to improve bone formation during fracture healing, and its osteogenic effects on osteoblast differentiation were mediated via the mTORC1 signaling pathway.

Synthesis and biological evaluation of novel (E)-N'-benzylidene hydrazides as novel c-Met inhibitors through fragment based virtual screening.

C-Met plays a crucial role in the development and progression of neoplastic disease. Type II c-Met inhibitors recognise the inactive DFG-out conformation of the kinase, result in better anti-tumour effects due to synergistic effect against the other kinases. According to our previous works, an (E)-N'-benzylidene group was selected as the initial fragment. Two series of (E)-N'-benzylidene hydrazides were designed by fragment growth method. The inhibitory activities were in vitro investigated against c-Met and VEGFR-2. Compound 10b exhibited the most potent inhibitory activity against the c-Met inhibitor (IC50 = 0.37 nM). Compound 11b exhibited multi-target c-Met kinase inhibitory activity as a potential type II c-Met inhibitor (IC50 = 3.41 nM against c-Met; 25.34 nM against VEGFR-2). The two compounds also demonstrate the feasibility of fragment-based virtual screening method for drug discovery.

Combination therapy with c-met inhibitor and TRAIL enhances apoptosis in dedifferentiated liposarcoma patient-derived cells.

BACKGROUND: Liposarcoma (LPS) is a tumor derived from adipose tissue, and has the highest incidence among soft tissue sarcomas. Dedifferentiated liposarcoma (DDLPS) is a malignant tumor with poor prognosis. Recurrence and metastasis rates in LPS remain high even after chemotherapy and radiotherapy following complete resection. Therefore, the development of advanced treatment strategies for LPS is required. In the present study, we investigated the effect of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) treatment, and of combination treatment using TRAIL and a c-Met inhibitor on cell viability and apoptosis in LPS and DDLPS cell lines of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) treatment, and of combination treatment using TRAIL and a c-Met inhibitor. METHODS: We analyzed cell viability after treatment with TRAIL and a c-Met inhibitor by measuring CCK8 and death receptor 5 (DR5) expression levels via fluorescence activated cell sorting (FACS) in both sarcoma cell lines and DDLPS patient-derived cells (PDCs). Moreover, we validated the effects of TRAIL alone and in combination with c-Met inhibitor on apoptosis in LPS cell lines and DDLPS PDCs via FACS. RESULTS: Our results revealed that combination treatment with a c-Met inhibitor and human recombinant TRAIL (rhTRAIL) suppressed cell viability and induced cell death in both sarcoma cell lines and DDLPS PDCs, which showed varying sensitivities to rhTRAIL alone. Also, we confirmed that treatment with a c-Met inhibitor upregulated DR5 levels in sarcoma cell lines and DDLPS PDCs. In both TRAIL-susceptible and TRAIL-resistant cells subjected to combination treatment, promotion of apoptosis was dependent on DR5 upregulation. CONCLUSION: From these results, our findings validated that DR5 up-regulation caused by combination therapy with a c-Met inhibitor and rhTRAIL enhanced TRAIL sensitization and promoted apoptosis. We propose the use of this approach to overcome TRAIL resistance and serve as a novel treatment strategy for clinical trials.

Synthesis, Evaluation, and Mechanism Study of New Tepotinib Derivatives as Antiproliferative Agents.

Inspired by the potent inhibition activity of the c-Met (mesenchymal-epithelial transition factor) inhibitor Tepotinib, a series of new Tepotinib derivatives were synthesized and evaluated for their ability to act as antiproliferative agents to find the leading compounds with good activity and limited side effects. Among them, compound 31e exhibited potent antiproliferative activity (IC50 (50% inhibitory concentration) = 0.026 µΜ) against hepatic carcinoma 97H (human liver cancer cell) cells and, importantly, had very low inhibitory activity against normal cells. A mechanism study demonstrated that 31e induced G1 phase (First growth phase or G indicating gap) arrest, inhibited the phosphorylation of c-Met and its downstream signaling component, Akt (Protein Kinase B), and also inhibited the migration of hepatic carcinoma 97H cells.

First-in-human phase I dose escalation study of MK-8033 in patients with advanced solid tumors.

Background C-Met, which is frequently activated in multiple cancers, has been implicated in tumor formation, progression, metastasis, angiogenesis, and resistance to multiple therapies. MK-8033 is a small-molecule inhibitor of c-Met that binds preferentially to the activated conformation, and has demonstrated anti-tumor activity in preclinical models. This first-in-human trial was performed to establish the safety and maximum tolerated dose (MTD), as well as preliminary pharmacokinetics (PK) and clinical activity. Methods Forty-seven patients were enrolled in three parts. The primary objective of Parts A and B was safety, whereas Part C evaluated the effect of proton-pump inhibitors on MK-8033 absorption. Dose escalation used an accelerated continual reassessment method, and dose-limiting toxicities (DLTs) were any treatment-related, first course non-hematologic grade ≥ 3 toxicity (except alopecia or inadequately treated nausea/vomiting/diarrhea), grade 4 hematologic toxicity (except grade 3 neutropenic fever and thrombocytopenia), or toxicity where treatment is held >3 weeks. Results Forty-six patients were treated across nine dose levels, and the MTD was 750 mg twice daily. DLTs were fatigue, nausea, vomiting, transaminitis, and hypokalemia. Most frequent toxicities were fatigue (28.3%), nausea (21.7%), and alopecia (19.6%), predominately grade ≤ 2. One patient with endometriod adenocarcinoma achieved a partial response and eight had stable disease. Median progression-free survival (PFS) was 57 days. Strikingly, the PFS for the one responder was 846 days. PK results showed that proton-pump inhibitors have no effect on MK-8033 absorption. Conclusion MK-8033 was well tolerated with no significant toxicity issues, albeit with limited clinical activity. Unfortunately, the company decided to discontinue further clinical development of MK-8033.

A phase-I study of lapatinib in combination with foretinib, a c-MET, AXL and vascular endothelial growth factor receptor inhibitor, in human epidermal growth factor receptor 2 (HER-2)-positive metastatic breast cancer.

BACKGROUND: The mechanisms of resistance to anti-human epidermal growth factor receptor 2 (HER 2) therapies are unclear but may include the tyrosine-protein kinase Met (c-Met), vascular endothelial growth factor (VEGF) and AXL pathways. Foretinib is an inhibitor of c-Met, VEGF receptor 2 (VEGFR-2), platelet-derived growth factor receptor beta (PDGFRB), AXL, Fms-like tyrosine kinase 3 (FLT3), angiopoiten receptor (TIE-2), RET and RON kinases. This phase Ib study sought to establish the associated toxicities, pharmacokinetics (PK) and recommended phase II doses (RP2D) of foretinib and lapatinib in a cohort of HER-2-positive patients with metastatic breast cancer (MBC). METHODS: Women with HER-2 positive MBC, Performance status (PS 0-2), and no limit on number of prior chemotherapies or lines of anti-HER-2 therapies were enrolled. A 3 + 3 dose escalation design was utilized. Four dose levels were intended with starting doses of foretinib 30 mg and lapatinib 750 mg orally once a day (OD) on a 4-weekly cycle. Assessment of c-MET status from the primary archival tissue was performed. RESULTS: We enrolled 19 patients, all evaluable for toxicity assessment and for response evaluation. Median age was 60 years (34-86 years), 95% were PS 0-1, 53% were estrogen receptor-positive and 95% had at least one prior anti-HER-2-based regimen. The fourth dose level was reached (foretinib 45 mg/lapatinib 1250 mg) with dose-limiting toxicities of grade-3 diarrhea and fatigue. There was only one grade-4 non-hematological toxicity across all dose levels. There were no PK interactions between the agents. A median of two cycles was delivered across the dose levels (range 1-20) with associated progression-free survival of 3.2 months (95% CI 1.61-4.34 months). By immunohistochemical assessment with a specified cutoff, none of the 17 samples tested were classified as positive for c-Met. CONCLUSIONS: The RP2D of the combined foretinib and lapatinib is 45 mg and 1000 mg PO OD, respectively. Limited activity was seen with this combination in a predominantly unselected cohort of HER-2-positive patients with MBC.

Design, synthesis and biological evaluation of 1H-pyrrolo[2,3-b]pyridine and 1H-pyrazolo[3,4-b]pyridine derivatives as c-Met inhibitors.

Five novel 1H-pyrrolo[2,3-b]pyridine or 1H-pyrazolo[3,4-b]pyridine derivatives, with a methylene, sulfur, sulfoxide or cyclopropyl group as a linker, were designed, synthesized and biologically evaluated against c-Met and ALK. The development of these methods of compound synthesis may provide an important reference for the construction of novel 7-azaindole and 7-azaindazole derivatives with a single atom linker. The enzyme assay and cell assay in vitro showed that compound 9 displayed strong c-Met kinase inhibition with IC50 of 22.8nM, moderate ALK kinase inhibition, and strong cell inhibition with MKN-45 IC50 of 329nM and EBC-1 IC50 of 479nM. In order to find the better candidate compounds, compounds 8, 9 and 10 have been selected as tool compounds for further optimization.

Stereoselective hydroxylation by CYP2C19 and oxidation by ADH4 in the in vitro metabolism of tivantinib.

1. In prior studies, it has been shown that tivantinib is extensively metabolized in humans to many oxidative metabolites and glucuronides. In order to identify the responsible enzymes, we investigated the in vitro metabolism of tivantinib and its four major circulating metabolites. 2. The primary isoforms involved in the elimination of tivantinib were CYP2C19 and CYP3A4/5. CYP2C19 showed catalytic activity for the formation of M5 (hydroxylated metabolite), but not for M4 (a stereoisomer of M5), whereas CYP3A4/5 catalyzed the formation of both metabolites. For the elimination of M4, M5 and M8 (keto-metabolite), CYP3A4/5 was the major cytochrome P450 isoform and UGT1A9 was mainly involved in the glucuronidation of M4 and M5. 3. ADH4 was identified as one of the major alcohol dehydrogenase isoforms contributing to the formation of M6 (sequential keto-metabolite of M4 and M5) and M8. The substrate preference of ADH for M4, and not M5, was observed in the formation of M6. 4. In conclusion, CYP2C19, CYP3A4/5, UGT1A9 and ADH4 were the primary drug metabolizing enzymes involved in the in vitro metabolism of tivantinib and its metabolites. The stereoselective hydroxylation by CYP2C19 and substrate stereoselectivity of ADH4-catalyzed oxidation in the in vitro metabolism of tivantinib was discovered.

Sustained inhibition of cMET-VEGFR2 signaling using liposome-mediated delivery increases efficacy and reduces toxicity in kidney cancer.

c-Met pathway is implicated in the resistance to anti-VEGF therapy in renal cell carcinoma (RCC). However, clinical translation of therapies targeting these pathways has been limited due to dose-limiting toxicities, feedback signaling, and low intratumoral drug accumulation. Here, we developed liposomes encapsulating a multi-receptor tyrosine kinase inhibitor (XL184) to explore the possibility of improving intratumoral concentration, enhancing antitumor efficacy and reducing toxicities. The liposomes showed increased cytotoxicity than XL184, and resulted in a sustained inhibition of phosphorylation of Met, AKT and MAPK pathways in RCC cells. In a RCC tumor xenograft model, the liposomes induced sustained inhibition of tumor growth as compared to XL184, consistent with higher inhibition of kinase signaling pathways. Biodistribution studies revealed higher accumulation of the liposomes in tumor, which translated into lower toxicities. This study shows the use of liposomes for effective inhibition of multi-kinase pathways, which can potentially emerge as a new treatment for RCC.

Phase I study of tivantinib in Japanese patients with advanced hepatocellular carcinoma: Distinctive pharmacokinetic profiles from other solid tumors.

A c-Met inhibitor tivantinib is a candidate anticancer agent for patients with hepatocellular carcinoma (HCC), and CYP2C19 is the key metabolic enzyme for tivantinib. Previous Japanese phase I studies in patients with solid tumors (except HCC) recommend 360 mg twice daily (BID) and 240 mg BID for CYP2C19 extensive metabolizers (EM) and poor metabolizers (PM), respectively. In this study, Japanese patients with HCC in whom sorafenib treatment has failed were enrolled to evaluate the safety, tolerability and pharmacokinetics of oral tivantinib as a single agent. The dose was escalated separately in EM and PM, from 120 mg BID to 240 mg BID, in both capsule and tablet formulations. A total of 28 patients (EM: 21, PM: 7) received tivantinib. At a dose of 120 mg BID, dose-limiting toxicities (DLT) did not develop in 12 EM (capsule: 6, tablet: 6) and 7 PM (capsule: 4, tablet: 3) during the DLT-observation period (for 29 days after first dosing). At this dose, the pharmacokinetic profiles of tivantinib (AUC0-12 and Cmax ) did not remarkably differ between EM and PM. When treated with 240 mg BID, 5 of 9 EM (capsule: 4 of 6, tablet: 1 of 3) developed neutropenia-related DLT accompanying plasma tivantinib concentration higher than expected from the previous studies. Consequently, PM did not receive 240 mg BID. In conclusion, 120 mg BID of tivantinib is recommended among Japanese patients with HCC regardless of CYP2C19 phenotype.

A randomized, double-blind, placebo-controlled, phase III trial of erlotinib with or without a c-Met inhibitor tivantinib (ARQ 197) in Asian patients with previously treated stage IIIB/IV nonsquamous nonsmall-cell lung cancer harboring wild-type epidermal growth factor receptor (ATTENTION study).

BACKGROUND: A previous randomized phase II study demonstrated that the addition of a c-Met inhibitor tivantinib to an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor erlotinib might prolong progression-free survival (PFS) in patients with previously treated, nonsquamous nonsmall-cell lung cancer (NSCLC). On a subset analysis, the survival benefit was greater in patients with wild-type EGFR (WT-EGFR) than in those with activating EGFR mutations. Herein, this phase III study compared overall survival (OS) between Asian nonsquamous NSCLC patients with WT-EGFR who received erlotinib plus tivantinib (tivantinib group) or erlotinib plus placebo (placebo group). METHODS: A total of 460 NSCLC patients were planned to be randomized to the tivantinib or placebo group. Primary end point was OS. Secondary end points were PFS, tumor response, and safety. Tissue was collected for biomarker analysis, including c-Met and HGF expression. RESULTS: Enrollment was stopped when 307 patients were randomized, following the Safety Review Committee's recommendation based on an imbalance in the interstitial lung disease (ILD) incidence between the groups. ILD developed in 14 patients (3 deaths) and 6 patients (0 deaths) in the tivantinib and the placebo groups, respectively. In the enrolled patients, median OS was 12.7 and 11.1 months in the tivantinib and the placebo groups, respectively [hazard ratio (HR) = 0.891, P = 0.427]. Median PFS was 2.9 and 2.0 months in the tivantinib and the placebo groups, respectively (HR = 0.719, P = 0.019). The commonly observed grade ≥ 3 adverse events in the tivantinib group were neutropenia (24.3%), leukopenia (18.4%), febrile neutropenia (13.8%), and anemia (13.2%). CONCLUSIONS: This study was prematurely terminated due to the increased ILD incidence in the tivantinib group. Although this study lacked statistical power because of the premature termination and did not demonstrate an improvement in OS, our results suggest that tivantinib plus erlotinib might improve PFS than erlotinib alone in nonsquamous NSCLC patients with WT-EGFR. TRIAL REGISTRATION NUMBER: NCT01377376.

Significance of c-MET overexpression in cytotoxic anticancer drug-resistant small-cell lung cancer cells.

The c-MET receptor tyrosine kinase is the receptor for hepatocyte growth factor. Recently, activation of the c-MET/hepatocyte growth factor signaling pathway was associated with poor prognosis in various solid tumors and was one of the mechanisms of acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitor, gefitinib. But the link between c-MET activation and the cytotoxic anticancer drug has not been fully examined. Here, we found that the enhanced expression and activation of c-MET in cytotoxic anticancer agent-resistant small-cell lung cancer cells. Downregulation of c-MET expression by siRNA against the c-MET gene or inhibition of c-MET activation by SU11274, a c-MET inhibitor, in the resistant cells altered resistance to the cytotoxic anticancer agent. These results indicated that c-MET overexpression might play an important role in acquired resistance to cytotoxic anticancer drugs. Furthermore, the number of c-MET gene loci was increased in the resistant cells compared to the parental cells. In conclusion, increased c-Met expression through an increase in the number of c-MET gene loci is one of the mechanisms of acquired resistance to cytotoxic anticancer drugs. Our results add a new strategy, the targeting of c-MET, for overcoming resistance to cytotoxic agents in small-cell lung cancer.

Discovery of substituted 6-pheny-3H-pyridazin-3-one derivatives as novel c-Met kinase inhibitors.

We report a series of phenyl substituted pyridazin-3-ones substituted with morpholino-pyrimidines. The SAR of the phenyl was explored and their c-Met kinase and cell-based inhibitory activity toward c-Met driven cell lines were evaluated. Described herein is a potent c-Met inhibitor by structural modification of the parent morpholino-pyridazinone scaffold, with particular focus on the phenyl and pyrimidine substituents.

Pharmacological mechanisms underlying the interaction of the nucleoside analogue gemcitabine with the c-MET inhibitor tivantinib in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is a deadly malignancy with limited treatment options, highlighting the urgent need for innovative approaches. A promising target for new anticancer therapies across various tumor types is the receptor tyrosine kinase c-MET. Here, we examined the impact of the c-MET inhibitor tivantinib in combination with gemcitabine on both primary and immortalized PDAC cells, and we investigated the mechanism underlying this combined treatment's effects. Our findings demonstrate that tivantinib is synergistic with gemcitabine, which is not related to cytidine deaminase but to inhibition of the polymerization of tubulin. Moreover, these drugs affected the expression of microRNAs miR-21 and miR-34, which regulate key oncogenic pathways. These findings might have an impact on the selection of patients for future trials.

Discovery of potent and selective c-Met inhibitors for MET-amplified hepatocellular carcinoma treatment.

Hepatocellular carcinoma (HCC) is a prevalent and lethal malignancy worldwide. The MET gene, which encodes receptor tyrosine kinase c-Met, is aberrantly activated in various solid tumors, including non-small cell lung cancer and HCC. In this study, we identified a novel c-Met inhibitor 54 by virtual screening and structural optimization. Compound 54 showed potent c-Met inhibition with an IC50 value of 0.45 ± 0.06 nM. It also exhibited high selectivity among 370 kinases and potent anti-proliferative activity against MET-amplified HCC cells. Moreover, compound 54 displayed significant anti-tumor efficacy in vivo, making it a potential candidate for HCC treatment in future studies.