pazopanib and trametinib

Advanced melanoma treatments often rely on immunotherapy or targeting mutations, with few treatment options for wild-type BRAF (BRAF-wt) melanoma. However, the mitogen-activated protein kinase pathway is activated in most melanoma, including BRAF-wt. We assessed whether inhibiting this pathway by adding kinase inhibitors trametinib or pazopanib to paclitaxel chemotherapy improved outcomes in patients with advanced BRAF-wt melanoma in a phase II, randomised and open-label trial.. Patients were randomised (1 : 1 : 1) to paclitaxel alone or with trametinib or pazopanib. Paclitaxel was given for a maximum of six cycles, while 2 mg trametinib and 800 mg pazopanib were administered orally once daily until disease progression or unacceptable toxicity. Participants and investigators were unblinded. The primary end point was progression-free survival (PFS). Key secondary end points included overall survival (OS) and objective response rate (ORR).. Participants were randomised to paclitaxel alone (n = 38), paclitaxel and trametinib (n = 36), or paclitaxel and pazopanib (n = 37). Adding trametinib significantly improved 6-month PFS [time ratio (TR), 1.47; 90% confidence interval (CI) 1.08-2.01, P = 0.04] and ORR (42% versus 13%; P = 0.01) but had no effect on OS (P = 0.25). Adding pazopanib did not benefit 6-month PFS; (TR 1.36; 90% CI 0.96-1.93; P = 0.14), ORR, or OS. Toxicity increased in both combination arms.. In this phase II trial, adding trametinib to paclitaxel chemotherapy for BRAF-wt melanoma improved PFS and substantially increased ORR but did not impact OS.This study was registered with the EU Clinical Trials Register, EudraCT number 2011-002545-35, and with the ISRCTN registry, number 43327231.

Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Combined Chemotherapy Protocols; Female; Follow-Up Studies; Humans; Indazoles; Male; Melanoma; Middle Aged; Mutation; Paclitaxel; Prognosis; Proto-Oncogene Proteins B-raf; Pyridones; Pyrimidines; Pyrimidinones; Sulfonamides; Survival Rate

Differentiated thyroid cancer (DTC) responds to VEGF receptor inhibitors. VEGF signals through RAS/RAF/MEK signaling. We evaluated the safety and efficacy of the VEGF receptor inhibitor pazopanib and MEK inhibitor trametinib in advanced solid tumors and DTC.. Patients with advanced solid tumors were enrolled in a phase I, multicenter trial with a DTC expansion cohort. Patients received pazopanib 400-800 mg and trametinib 1-2 mg daily. Efficacy in the expansion cohort was assessed with objective response (OR) at 6 months of treatment.. Twenty-six patients were enrolled in five dose levels. MTD was not reached; the recommended phase II dose was pazopanib 800 mg orally and trametinib 2 mg orally every day. There was one dose-limiting toxicity on dose level 1 with grade 3 fatigue and muscle weakness. Common grade 3 adverse events were elevated transaminases (19%), diarrhea (15%), hypertension (12%), and fatigue (8%). Thirteen patients were enrolled in the DTC cohort; OR was 33% (95% confidence interval, 9.9, 65.1%) and median progression-free survival was 10.7 months. The cohort was terminated after planned interim analysis suggested insufficiently increased activity against the historical control of pazopanib alone. Reduction in tumor diameter negatively correlated with p-ERK change in tumor (Spearman ρ = -0.71;. Pazopanib + trametinib was tolerable at full single-agent doses with clinical activity in DTC but did not achieve the prespecified response rate target.

Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Combined Chemotherapy Protocols; Biomarkers, Tumor; Female; Humans; Indazoles; Kaplan-Meier Estimate; Male; Middle Aged; Mutation; Protein Kinase Inhibitors; Pyridones; Pyrimidines; Pyrimidinones; Receptors, Vascular Endothelial Growth Factor; Sulfonamides; Thyroid Neoplasms; Treatment Outcome

Topics: Humans; Indazoles; Melanoma; Paclitaxel; Proto-Oncogene Proteins B-raf; Pyridones; Pyrimidines; Pyrimidinones; Sulfonamides

A sensitive and selective method of high performance liquid chromatography (HPLC) coupled to tandem mass spectrometry (MS/MS) has been developed for the simultaneous quantification of six anticancer protein kinase inhibitors (PKIs), dabrafenib, trametinib, vemurafenib, cobimetinib, pazopanib, regorafenib, and two active metabolites (regorafenib-M2 and regorafenib-M5) in human plasma. Plasma protein precipitation with methanol enables the sample extraction of 100 μL aliquot of plasma. Analytes are detected by electrospray triple-stage quadrupole mass spectrometry and quantified using the calibration curves with stable isotope-labeled internal standards. The method was validated based on FDA recommendations, including assessment of extraction yield (74-104%), matrix effects, analytical recovery (94-104%) with low variability (<15%). The method is sensitive (lower limits of quantification within 1 to 200 ng/mL), accurate (intra- and inter-assay bias: -0.3% to +12.7%, and -3.2% to +6.3%, respectively) and precise (intra- and inter-assay CVs within 0.7-7.3% and 2.5-8.0%, respectively) over the clinically relevant concentration range (upper limits of quantification 500 to 100,000 ng/mL). This method is applied in our laboratory for both clinical research programs and routine therapeutic drug monitoring service of PKIs.

Topics: Administration, Oral; Antineoplastic Agents; Azetidines; Child; Chromatography, High Pressure Liquid; Humans; Imidazoles; Indazoles; Indoles; Limit of Detection; Linear Models; Oximes; Phenylurea Compounds; Piperidines; Pyridines; Pyridones; Pyrimidines; Pyrimidinones; Reproducibility of Results; Sulfonamides; Tandem Mass Spectrometry; Vemurafenib

Synovial sarcoma (SS) is a rare high-grade malignant mesenchymal tumour with a relatively poor prognosis despite intensive multimodal therapy. Although pazopanib, a multi-kinase inhibitor, is often used for advanced SS, most cases eventually become resistant to pazopanib. In the present study, we investigated the mechanisms of acquired pazopanib resistance in SS. To examine acquired pazopanib resistance, two SS cell lines, SYO-1 and HS-SY-II, were isolated after multiple selection steps with increasing concentrations of pazopanib. SYO-1 was also used in vivo. Then, pazopanib-resistant clones were investigated to assess potential mechanisms of acquired pazopanib resistance. Stable pazopanib-resistant clones were established and exhibited enhanced cell cycle progression, cell growth with increased ERK1/2 phosphorylation, and higher sensitivity than parental cells to a MEK-inhibitor, trametinib, both in vitro and in vivo. Furthermore, addition of low-dose trametinib partially reversed the pazopanib resistance. In the pazopanib-resistant clones, dual specificity phosphatase 6 (DUSP6) was downregulated. Inhibition of DUSP6 expression in parental HS-SY-II cells partially recapitulated acquired pazopanib resistance. Acquired pazopanib resistance in SS was associated with activation of ERK1/2 through downregulation of DUSP6 expression. Simultaneous treatment with pazopanib and a MEK inhibitor could be a promising strategy to overcome pazopanib resistance in SS.

Topics: Animals; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Down-Regulation; Drug Resistance, Neoplasm; Dual Specificity Phosphatase 6; Female; Humans; Indazoles; Mice; Mice, Inbred BALB C; Mice, Nude; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-raf; Pyridones; Pyrimidines; Pyrimidinones; ras Proteins; Sarcoma, Synovial; Sulfonamides

Cholangiocarcinoma is an aggressive malignancy with limited therapeutic options. MEK inhibition and antiangiogenic therapies have individually shown modest activity in advanced cholangiocarcinoma, whereas dual inhibition of these pathways has not been previously evaluated. We evaluated the safety and efficacy of combination therapy with the oral VEGF receptor tyrosine kinase inhibitor pazopanib plus the MEK inhibitor trametinib in patients with advanced cholangiocarcinoma.. In this open-label, multicentre, single-arm trial, adults with advanced unresectable cholangiocarcinoma received pazopanib 800 mg daily and trametinib 2 mg daily until disease progression or unacceptable toxicity. The primary end point was progression-free survival (PFS) with secondary end points including overall survival (OS), response rate, and disease control rate (DCR).. A total of 25 patients were enrolled and had received a median of 2 prior systemic therapies (range 1-7). Median PFS was 3.6 months (95% CI: 2.7-5.1) and the 4-month PFS was 40% (95% CI: 24.7-64.6%). There was a trend towards increased 4-month PFS as compared with the prespecified null hypothesised 4-month PFS of 25%, but this difference did not reach statistical significance (P=0.063). The median survival was 6.4 months (95% CI: 4.3-10.2). The objective response rate was 5% (95% CI: 0.13-24.9%) and the DCR was 75% (95% CI: 51%, 91%). Grade 3/4 adverse events attributable to study drugs were observed in 14 (56%) and included thrombocytopenia, abnormal liver enzymes, rash, and hypertension.. Although the combination of pazopanib plus trametinib had acceptable toxicity with evidence of clinical activity, it did not achieve a statistically significant improvement in 4-month PFS over the prespecified null hypothesised 4-month PFS.

Topics: Administration, Oral; Adult; Aged; Aged, 80 and over; Antineoplastic Combined Chemotherapy Protocols; Bile Duct Neoplasms; Cholangiocarcinoma; Disease Progression; Disease-Free Survival; Drug Eruptions; Exanthema; Female; Humans; Hypertension; Indazoles; Male; MAP Kinase Kinase Kinases; Middle Aged; Protein Kinase Inhibitors; Pyridones; Pyrimidines; Pyrimidinones; Receptors, Vascular Endothelial Growth Factor; Sulfonamides; Survival Rate; Thrombocytopenia

Studies focused on the killing of activated B-RAF melanoma cells by the histone deacetylase (HDAC) inhibitor AR42. Compared to other tumor cell lines, PDX melanoma isolates were significantly more sensitive to AR42-induced killing. AR42 and the multi-kinase inhibitor pazopanib interacted to activate: an eIF2α-Beclin1 pathway causing autophagosome formation; an eIF2α-DR4/DR5/CD95 pathway; and an eIF2α-dependent reduction in the expression of c-FLIP-s, MCL-1 and BCL-XL. AR42 did not alter basal chaperone activity but increased the ability of pazopanib to inhibit HSP90, HSP70 and GRP78. AR42 and pazopanib caused HSP90/HSP70 dissociation from RAF-1 and B-RAF that resulted in reduced 'RAF' expression. The drug combination activated a DNA-damage-ATM-AMPK pathway that was associated with: NFκB activation; reduced mTOR S2448 and ULK-1 S757 phosphorylation; and increased ULK-1 S317 and ATG13 S318 phosphorylation. Knock down of PERK, eIF2α, Beclin1, ATG5 or AMPKα, or expression of IκB S32A S36A, ca-mTOR or TRX, reduced cell killing. AR42, via lysosomal degradation, reduced the protein expression of HDACs 2/5/6/10/11. In vivo, a 3-day exposure of dabrafenib/trametinib resistant melanoma cells to the AR42 pazopanib combination reduced tumor growth and enhanced survival from ~25 to ~40 days. Tumor cells that had adapted through therapy exhibited elevated HGF expression and the c-MET inhibitor crizotinib enhanced AR42 pazopanib lethality in this evolved drug-resistant population.

Topics: Angiogenesis Inhibitors; Animals; Antineoplastic Combined Chemotherapy Protocols; Autophagosomes; Blotting, Western; Cell Line, Tumor; Cell Survival; Drug Resistance, Neoplasm; Drug Synergism; Endoplasmic Reticulum Chaperone BiP; Eukaryotic Initiation Factor-2; Histone Deacetylase 6; Histone Deacetylase Inhibitors; Histone Deacetylases; Humans; Imidazoles; Indazoles; Kaplan-Meier Estimate; Male; Melanoma; Mice, Nude; Microscopy, Fluorescence; Oximes; Phenylbutyrates; Pyridones; Pyrimidines; Pyrimidinones; RNA Interference; Signal Transduction; Sulfonamides; Xenograft Model Antitumor Assays

Multikinase inhibitors (MKIs) targeting VEGF receptors and other receptor tyrosine kinases have shown considerable activity in clinical trials of thyroid cancer. Thyroid cancer frequently exhibits activation of the RAS/RAF/MEK/ERK pathway. In other types of cancer, paradoxical ERK activation has emerged as a potential resistance mechanism to RAF-inhibiting drugs including MKIs such as sorafenib and pazopanib. We therefore queried whether the MEK inhibitor trametinib, could augment the activity of pazopanib in thyroid cancer cell lines. Trametinib potently inhibited growth in vitro (GI50 1.1-4.8 nM), whereas pazopanib had more limited in vitro activity, as anticipated (GI50 1.4-7.1 µM). We observed progressive upregulation of ERK activity with pazopanib treatment, an effect abrogated by trametinib. For xenografts (bearing either KRASG12R or BRAFV600E mutations), the combination of trametinib and pazopanib led to sustained shrinkage in tumor volume by 50% or more, compared to pre-treatment baseline. Trametinib also was highly effective as a single agent, compared to pazopanib alone. These preclinical findings support the evaluation of trametinib, alone or in combination with pazopanib or other kinase inhibitors, in thyroid cancer clinical trials. We highlight the importance of pharmacodynamic assessment of the ERK pathway for patients enrolled in trials involving MKIs.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Cell Line, Tumor; Cell Proliferation; Extracellular Signal-Regulated MAP Kinases; Female; Humans; Indazoles; MAP Kinase Signaling System; Mice, Nude; Pyridones; Pyrimidines; Pyrimidinones; Sulfonamides; Thyroid Neoplasms; Tumor Burden; Xenograft Model Antitumor Assays