cabozantinib and Stomach-Neoplasms

This is the phase Ib part of the phase I/II CAMILLA trial evaluating cabozantinib plus durvalumab in advanced chemo-refractory proficient mismatch repair or microsatellite stable (pMMR/MSS) gastrointestinal malignancies including gastric/gastroesophageal junction/esophageal (G/GEJ/E) adenocarcinoma, colorectal cancer (CRC), and hepatocellular carcinoma (HCC). Thirty-five patients are enrolled. There are no observed dose-limiting toxicities during dose escalation. The overall grade 3/4 treatment-related adverse event rate is 34%. Among evaluable patients (n = 30), the objective response rate (ORR) is 30%, disease control rate (DCR) 83.3%, 6-month progression-free survival (PFS) 36.7%, median PFS 4.5 months, and median overall survival (OS) 8.7 months. Responses are seen in 4 of 17, 3 of 10, and 2 of 3 patients with CRC, G/GEJ/E adenocarcinoma, and HCC, respectively. Participants with a PD-L1 combined positive score (CPS) ≥5 have numerically higher ORR, PFS, and OS. Cabozantinib plus durvalumab demonstrates a tolerable safety profile and potential efficacy in previously treated advanced pMMR/MSS gastrointestinal malignancies.

Topics: Adenocarcinoma; Antibodies, Monoclonal, Humanized; Carcinoma, Hepatocellular; Humans; Liver Neoplasms; Stomach Neoplasms

Scirrhous gastric cancer frequently develops into peritoneal carcinomatosis with malignant ascites, leading to an extremely poor prognosis. We had demonstrated that paracrine hepatocyte growth factor (HGF)-induced MET activation promotes peritoneal carcinomatosis with ascites formation. The vascular endothelial growth factor (VEGF) receptor (VEGFR)/VEGF axis facilitates tumor progression and formation of malignant ascites. This study investigated the role of MET and VEGFR2 in the development of peritoneal carcinomatosis with malignant ascites. Cabozantinib is a dual inhibitor of MET and VEGFR2. We examined the effects of cabozantinib on MET- and VEGFR2-mediated progression of peritoneal carcinomatosis in human scirrhous gastric cancer in vitro and in vivo. Cabozantinib inhibited HGF-stimulated proliferation of scirrhous cancer cell lines NUGC4 and GCIY, with a high potential to generate peritoneal carcinomatosis with ascites fluid, as well as the constitutive proliferation of MKN45 cells with MET amplification. Cabozantinib also inhibited the phosphorylation of both MET and VEGFR2 in scirrhous cancer cells and HGF- or VEGF-stimulated HUVECs. It effectively reduced ascitic fluid and prolonged the survival of NUGC4-inoculated nude mice. In clinical specimens, malignant ascites fluid from patients with peritoneal carcinomatosis contained high levels of HGF and VEGF. Our results strongly suggest that MET- and VEGFR2-mediated signaling pathways play pivotal roles in the pathogenesis of peritoneal carcinomatosis in scirrhous gastric cancer. Thus, the dual blockade of MET and VEGFR2 signaling may be a potential therapeutic maneuver for peritoneal carcinomatosis in scirrhous gastric cancer.

Topics: Anilides; Animals; Ascites; Cell Line, Tumor; Humans; Mice; Mice, Nude; Peritoneal Neoplasms; Proto-Oncogene Proteins c-met; Pyridines; Signal Transduction; Stomach Neoplasms; Vascular Endothelial Growth Factor Receptor-2

The c-Met D1228V/H/N mutation clinically causes acquired resistance to type I tyrosine kinase inhibitors (TKIs), while maintaining sensitivity to type II TKIs in targeted gastric cancer therapy. The mutation is located in the activation loop (A-loop) region of the c-Met kinase domain, which substitutes the negatively charged residue Asp1228 with electroneutral amino acid Val, His, or Asn, thus electrostatically destabilizing the DFG-in conformation of A-loop and inducing its transition to DFG-out state. The transition is spontaneous in a dynamics point of view and the A-loop exhibits a large intrinsic disorder during the transitional dynamics course. In DFG-in conformation, the wild-type Asp1228 is surrounded by a number of positively charged residues within its first and second shells, which can also form a hydrogen-bonding network with its vicinal residues Phe1089, Lys1110, Asp1222, and Met1229 in the first shell. Type I and type II TKIs respond oppositely to the mutation; the former shows a generic resistance to the mutation, whereas the latter is generally sensitized by the mutation. Both types of TKIs do not directly interact with the mutation. Instead, the mutation-induced conformational change in A-loop reshapes kinase active site and then influences the site interactions with inhibitor ligands, thus conferring different selectivity to the type I and type II TKIs. Graphical abstract The molecular mechanism of D1228V/H/N mutation-induced inhibitor resistance and sensitivity in c-Met kinase is investigated. The mutation electrostatically destabilizes the DFG-in conformation of kinase A-loop and induces its spontaneous transition to DFG-out state, which reshapes kinase active site and influences the site interactions with inhibitor ligands.

Topics: Anilides; Binding Sites; Drug Resistance, Neoplasm; Humans; Molecular Dynamics Simulation; Molecular Structure; Molecular Targeted Therapy; Mutation; Protein Binding; Protein Conformation; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-met; Pyrazines; Pyridines; Static Electricity; Stomach Neoplasms; Triazines

Cancer treatment, especially that for breast and lung cancer, has entered a new era and continues to evolve, with the development of genome analysis technology and the advent of molecular targeted drugs including tyrosine kinase inhibitors. Nevertheless, acquired drug resistance to molecular targeted drugs is unavoidable, creating a clinically challenging problem. We recently reported the antitumor effect of a pan-HER inhibitor, afatinib, against human epidermal growth factor receptor 2 (HER2)-amplified gastric cancer cells. The purpose of the present study was to identify the mechanisms of acquired afatinib resistance and to investigate the treatment strategies for HER2-amplified gastric cancer cells. Two afatinib-resistant gastric cancer cell lines were established from 2 HER2-amplified cell lines, N87 and SNU216. Subsequently, we investigated the molecular profiles of resistant cells. The activation of the HER2 pathway was downregulated in N87-derived resistant cells, whereas it was upregulated in SNU216-derived resistant cells. In the N87-derived cell line, both MET and AXL were activated, and combination treatment with afatinib and cabozantinib, a multikinase inhibitor that inhibits MET and AXL, suppressed the cell growth of cells with acquired resistance both in vitro and in vivo. In the SNU216-derived cell line, YES1, which is a member of the Src family, was remarkably activated, and dasatinib, a Src inhibitor, exerted a strong antitumor effect in these cells. In conclusion, we identified MET and AXL activation in addition to YES1 activation as novel mechanisms of afatinib resistance in HER2-driven gastric cancer. Our results also indicated that treatment strategies targeting individual mechanisms of resistance are key to overcoming such resistance.

Topics: Afatinib; Anilides; Animals; Antineoplastic Agents; Cell Line, Tumor; Cell Proliferation; Down-Regulation; Drug Resistance, Neoplasm; Mice; Proto-Oncogene Proteins c-yes; Pyridines; Receptor, ErbB-2; Signal Transduction; src-Family Kinases; Stomach Neoplasms; Up-Regulation; Xenograft Model Antitumor Assays

The use of clinical MRI scanners to conduct pre-clinical research facilitates comparisons with clinical studies. Here the utility and sensitivity of anatomical and functional MRI data/biomarkers acquired from transgenic mouse models of neuroblastoma using a dedicated radiofrequency (RF) coil on a clinical 3T scanner was evaluated.. Multiparametric MRI of transgenic mice bearing abdominal neuroblastomas was performed at 3T, and data cross-referenced to that acquired from the same mice on a pre-clinical 7T MRI system. T. Excellent T. Simultaneous multiparametric MRI of multiple tumour-bearing animals using this coil arrangement at 3T can provide high efficiency/throughput for both phenotypic characterisation and evaluation of novel therapeutics, and facilitate the introduction of functional MRI biomarkers into aligned imaging-embedded clinical trials.

Topics: Anaplastic Lymphoma Kinase; Anilides; Animals; Antineoplastic Agents; Contrast Media; Cyclophosphamide; Disease Models, Animal; Female; Magnetic Resonance Imaging; Magnets; Male; Mice; Mice, Transgenic; Mutation; N-Myc Proto-Oncogene Protein; Neuroblastoma; Phantoms, Imaging; Phenotype; Pyridines; Receptor Protein-Tyrosine Kinases; Signal-To-Noise Ratio; Stomach Neoplasms; Tumor Burden