sirolimus and trametinib

This phase Ib trial investigated the safety, tolerability, and recommended phase II dose and schedule of the MEK inhibitor trametinib in combination with the mammalian target of rapamycin (mTOR) inhibitor everolimus. Secondary objectives included pharmacokinetic (PK) characterization and evaluation of clinical activity.. A total of 67 patients with advanced solid tumors were enrolled in this open-label, single-arm, dose-escalation study. Dose escalation followed a 3 + 3 design. Patients were assigned to one of 10 different cohorts, involving either daily dosing with both agents or daily dosing with trametinib and intermittent everolimus dosing. This included an expansion cohort comprising patients with pancreatic tumors. PKs samples were collected predose, as well as 1, 2, 4, and 6 h post-dose on day 15 of the first treatment cycle.. Concurrent treatment with trametinib and everolimus resulted in frequent treatment-related adverse events, including mucosal inflammation (40%), stomatitis (25%), fatigue (54%), and diarrhea (42%). PK assessment did not suggest drug-drug interactions between these two agents. Of the 67 enrolled patients, 5 (7%) achieved partial response (PR) to treatment and 21 (31%) displayed stable disease (SD). Among the 21 patients with pancreatic cancer, PR was observed in 1 patient (5%) and SD in 6 patients (29%).. This study was unable to identify a recommended phase II dose and schedule of trametinib in combination with everolimus that provided an acceptable tolerability and adequate drug exposure.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Antineoplastic Combined Chemotherapy Protocols; Drug Administration Schedule; Everolimus; Female; Humans; Male; MAP Kinase Kinase 1; MAP Kinase Kinase 2; Middle Aged; Neoplasms; Protein Kinase Inhibitors; Pyridones; Pyrimidinones; Sirolimus; TOR Serine-Threonine Kinases; Treatment Outcome; Young Adult

We investigated why three patient-derived xenograft (PDX) childhood BRAFV600E-mutant brain tumor models are highly sensitive to trametinib. Mechanisms of acquired resistance selected in situ, and approaches to prevent resistance were also examined, which may translate to both low-grade glioma (LGG) molecular subtypes.. Sensitivity to trametinib [MEK inhibitor (MEKi)] alone or in combination with rapamycin (TORC1 inhibitor), was evaluated in pediatric PDX models. The effect of combined treatment of trametinib with rapamycin on development of trametinib resistance in vivo was examined. PDX tissue and tumor cells from trametinib-resistant xenografts were characterized.. In pediatric models TORC1 is activated through ERK-mediated inactivation of the tuberous sclerosis complex (TSC): consequently inhibition of MEK also suppressed TORC1 signaling. Trametinib-induced tumor regression correlated with dual inhibition of MAPK/TORC1 signaling, and decoupling TORC1 regulation from BRAF/MAPK control conferred trametinib resistance. In mice, acquired resistance to trametinib developed within three cycles of therapy in all three PDX models. Resistance to trametinib developed in situ is tumor-cell-intrinsic and the mechanism was tumor line specific. Rapamycin retarded or blocked development of resistance.. In these three pediatric BRAF-mutant brain tumors, TORC1 signaling is controlled by the MAPK cascade. Trametinib suppressed both MAPK/TORC1 pathways leading to tumor regression. While low-dose intermittent rapamycin to enhance inhibition of TORC1 only modestly enhanced the antitumor activity of trametinib, it prevented or retarded development of trametinib resistance, suggesting future therapeutic approaches using rapamycin analogs in combination with MEKis that may be therapeutically beneficial in both KIAA1549::BRAF- and BRAFV600E-driven gliomas.

Topics: Animals; Brain Neoplasms; Cell Line, Tumor; Disease Models, Animal; Glioma; Humans; Mechanistic Target of Rapamycin Complex 1; Mice; Mitogen-Activated Protein Kinase Kinases; Mutation; Protein Kinase Inhibitors; Proto-Oncogene Proteins B-raf; Pyridones; Pyrimidinones; Sirolimus

We evaluated the radiosensitizing effect of the combination treatment of trametinib, a MEK inhibitor, and temsirolimus, an mTOR inhibitor, on non-small-cell lung carcinoma (NSCLC) cells.. The effects of combining trametinib and temsirolimus with radiation in NSCLC cell lines were evaluated using clonogenic survival and apoptosis assays. DNA double-strand breaks and cell cycle distribution were analyzed using flow cytometry. Tumor volume was measured to determine the radiosensitivity in lung cancer xenograft models.. The combination of trametinib and temsirolimus can enhance lung cancer radiosensitivity in vitro and in vivo.

Topics: Apoptosis; Carcinoma, Non-Small-Cell Lung; Cell Cycle; Cell Line, Tumor; DNA Damage; Drug Therapy, Combination; Humans; Lung Neoplasms; MAP Kinase Kinase Kinases; Pyridones; Pyrimidinones; Radiation Tolerance; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Tumor Cells, Cultured

Detection of KRAS mutation in skin biopsy in a patient with melorheostosis, lymphantiomatosis and vascular stenosis. She was successfully treated with trametinib.

Topics: Antineoplastic Combined Chemotherapy Protocols; Biopsy; Child, Preschool; Disease Management; DNA-Binding Proteins; Female; Genetic Association Studies; Genetic Predisposition to Disease; Germ-Line Mutation; Humans; Lymphangioleiomyomatosis; Melorheostosis; Membrane Proteins; Mutation; Proto-Oncogene Proteins p21(ras); Pyridones; Pyrimidinones; Sirolimus; Tomography, X-Ray Computed; Treatment Outcome

Mammalian target of rapamycin (mTOR) is one of the most commonly activated pathways in human cancers, including lung cancer. Targeting mTOR with molecule inhibitors is considered as a useful therapeutic strategy. However, the results obtained from the clinical trials with the inhibitors so far have not met the original expectations, largely because of the drug resistance. Thus, combined or multiple drug therapy can bring about more favorable clinical outcomes. Here, we found that activation of ERK pathway was responsible for rapamycin drug resistance in non-small-cell lung cancer (NSCLC) cells. Accordingly, rapamycin-resistant NSCLC cells were more sensitive to ERK inhibitor (ERKi), trametinib, and in turn, trametinib-resistant NSCLC cells were also susceptible to rapamycin. Combining rapamycin with trametinib led to a potent synergistic antitumor efficacy, which induced G1-phase cycle arrest and apoptosis. In addition, rapamycin synergized with another ERKi, MEK162, and in turn, trametinib synergized with other mTORi, Torin1 and OSI-027. Mechanistically, rapamycin in combination with trametinib resulted in a greater decrease of phosphorylation of AKT, ERK, mTOR and 4EBP1. In xenograft mouse model, co-administration of rapamycin and trametinib caused a substantial suppression in tumor growth without obvious drug toxicity. Overall, our study identifies a reasonable combined strategy for treatment of NSCLC.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Blotting, Western; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Drug Synergism; Extracellular Signal-Regulated MAP Kinases; Female; Humans; Immunohistochemistry; Lung Neoplasms; Mice, Inbred BALB C; Phosphorylation; Proto-Oncogene Proteins c-akt; Pyridones; Pyrimidinones; Sirolimus; Xenograft Model Antitumor Assays

Increasing life expectancy is causing the prevalence of age-related diseases to rise, and there is an urgent need for new strategies to improve health at older ages. Reduced activity of insulin/insulin-like growth factor signaling (IIS) and mechanistic target of rapamycin (mTOR) nutrient-sensing signaling network can extend lifespan and improve health during aging in diverse organisms. However, the extensive feedback in this network and adverse side effects of inhibition imply that simultaneous targeting of specific effectors in the network may most effectively combat the effects of aging. We show that the mitogen-activated protein kinase kinase (MEK) inhibitor trametinib, the mTOR complex 1 (mTORC1) inhibitor rapamycin, and the glycogen synthase kinase-3 (GSK-3) inhibitor lithium act additively to increase longevity in

Topics: Aged; Aging; Animals; Drosophila; Drosophila Proteins; Drug Combinations; Female; Glycogen Synthase Kinase 3; Humans; Lithium; Longevity; Mechanistic Target of Rapamycin Complex 1; Middle Aged; Nutrients; Pyridones; Pyrimidinones; Signal Transduction; Sirolimus

Topics: Animals; Computational Biology; CRISPR-Cas Systems; Drosophila; Drug Interactions; Gene Expression Regulation; Gene Knockout Techniques; Gene Library; Genes, Essential; Genetic Fitness; Genome-Wide Association Study; Pharmacogenetics; Phenotype; Protein Kinase Inhibitors; Pyridones; Pyrimidinones; Sirolimus

mTOR inhibition has emerged as a promising strategy for head and neck squamous cell carcinomas (HNSCC) treatment. However, most targeted therapies ultimately develop resistance due to the activation of adaptive survival signaling mechanisms limiting the activity of targeted agents. Thus, co-targeting key adaptive mechanisms may enable more effective cancer cell killing. Here, we performed a synthetic lethality screen using shRNA libraries to identify druggable candidates for combinatorial signal inhibition. We found that the ERK pathway was the most highly represented. Combination of rapamycin with trametinib, a MEK1/2 inhibitor, demonstrated strong synergism in HNSCC-derived cells in vitro and in vivo, including HNSCC cells expressing the HRAS and PIK3CA oncogenes. Interestingly, cleaved caspase-3 was potently induced by the combination therapy in PIK3CA+ cells in vitro and tumor xenografts. Moreover, ectopic expression of PIK3CA mutations into PIK3CA- HNSCC cells sensitized them to the pro-apoptotic activity of the combination therapy. These findings indicate that co-targeting the mTOR/ERK pathways may provide a suitable precision strategy for HNSCC treatment. Moreover, PIK3CA+ HNSCC are particularly prone to undergo apoptosis after mTOR and ERK inhibition, thereby providing a potential biomarker of predictive value for the selection of patients that may benefit from this combination therapy.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Cell Line, Tumor; Class I Phosphatidylinositol 3-Kinases; Drug Synergism; Female; Heterografts; Humans; MAP Kinase Signaling System; Mice; Mice, Nude; Molecular Targeted Therapy; Mouth Neoplasms; Pyridones; Pyrimidinones; RNA Interference; Sirolimus; TOR Serine-Threonine Kinases

Rapamycin analogues have antitumor efficacy in several tumor types, however few patients demonstrate tumor regression. Thus, there is a pressing need for markers of intrinsic response/resistance and rational combination therapies. We hypothesized that epithelial-to-mesenchymal transition (EMT) confers rapamycin resistance. We found that the epithelial marker E-cadherin protein is higher in rapamycin sensitive (RS) cells and mesenchymal breast cancer cell lines selected by transcriptional EMT signatures are less sensitive to rapamycin. MCF7 cells, transfected with constitutively active mutant Snail, had increased rapamycin resistance (RR) compared to cells transfected with wild-type Snail. Conversely, we transfected two RR mesenchymal cell lines-ACHN and MDA-MB-231-with miR-200b/c or ZEB1 siRNA to promote mesenchymal-to-epithelial transition. This induced E-cadherin expression in both cell lines, and ACHN demonstrated a significant increase in RS. Treatment of ACHN and MDA-MB-231 with trametinib modulated EMT in ACHN cells in vitro. Treatment of MDA-MB-231 and ACHN xenografts with trametinib in combination with rapamycin resulted in significant growth inhibition in both but without an apparent effect on EMT. Future studies are needed to determine whether EMT status is predictive of sensitivity to rapalogs and to determine whether combination therapy with EMT modulating agents can enhance antitumor effects of PI3K/mTOR inhibitors.

Topics: Animals; Antigens, CD; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Cadherins; Cell Proliferation; Dose-Response Relationship, Drug; Drug Resistance, Neoplasm; Epithelial-Mesenchymal Transition; Extracellular Signal-Regulated MAP Kinases; Female; Gene Expression Regulation, Neoplastic; Histone Deacetylase Inhibitors; Homeodomain Proteins; Humans; MCF-7 Cells; Mice, Nude; MicroRNAs; Mitogen-Activated Protein Kinase Kinases; Mutation; Phosphorylation; Protein Kinase Inhibitors; Pyridones; Pyrimidinones; RNA Interference; Sirolimus; Snail Family Transcription Factors; Time Factors; TOR Serine-Threonine Kinases; Transcription Factors; Transfection; Tumor Burden; Xenograft Model Antitumor Assays; Zinc Finger E-box-Binding Homeobox 1

Cellular signaling pathways involving mTOR, PI3K and ERK have dominated recent studies of breast cancer biology, and inhibitors of these pathways have formed a focus of numerous clinical trials. We have chosen trametinib, a drug targeting MEK in the ERK pathway, to address two questions. Firstly, does inhibition of a signaling pathway, as measured by protein phosphorylation, predict the antiproliferative activity of trametinib? Secondly, do inhibitors of the mTOR and PI3K pathways synergize with trametinib in their effects on cell proliferation? A panel of 30 human breast cancer cell lines was chosen to include lines that could be classified according to whether they were ER and PR positive, HER2 over-expressing, and "triple negative". Everolimus (targeting mTOR), NVP-BEZ235 and GSK2126458 (both targeting PI3K/mTOR) were chosen for combination experiments. Inhibition of cell proliferation was measured by IC50 values and pathway utilization was measured by phosphorylation of signaling kinases. Overall, no correlation was found between trametinib IC50 values and inhibition of ERK signaling. Inhibition of ERK phosphorylation was observed at trametinib concentrations not affecting proliferation, and sensitivity of cell proliferation to trametinib was found in cell lines with low ERK phosphorylation. Evidence was found for synergy between trametinib and either everolimus, NVP-BEZ235 or GSK2126458, but this was cell line specific. The results have implications for the clinical application of PI3K/mTOR and MEK inhibitors.

Topics: Antineoplastic Agents; Blotting, Western; Breast Neoplasms; Cell Line, Tumor; Cell Proliferation; Drug Synergism; Everolimus; Extracellular Signal-Regulated MAP Kinases; Female; Humans; Imidazoles; Inhibitory Concentration 50; MAP Kinase Signaling System; MCF-7 Cells; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Phosphorylation; Proto-Oncogene Proteins c-akt; Pyridazines; Pyridones; Pyrimidinones; Quinolines; Signal Transduction; Sirolimus; Sulfonamides; TOR Serine-Threonine Kinases