pazopanib and Melanoma

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

This phase II study evaluated the safety and clinical activity of pazopanib, a potent and mutlitargeted tyrosine kinase inhibitor (TKI) of vascular endothelial growth factor receptors (VEGFRs)-1, -2 and -3, platelet-derived growth factor receptor (PDGFR)-α and β, and cKit, in combination with metronomic paclitaxel in patients with metastatic melanoma.. Sixty chemotherapy-naive patients received pazopanib at a starting dose of 800 mg daily in combination with metronomic dosing of paclitaxel 80 mg/m. The 6-month PFS rate was 68%, with a 1-year OS rate of 48%. Objective response rate was 37% comprising one complete and 20 partial responses. Stable disease at 8 weeks was noted in 32 patients (55%) with an overall clinical benefit rate of 93%. Six-month median progression-free survival was 8 months and median OS was 12.7 months. The most frequently (> 15%) reported non-hematologic, treatment-related adverse events were fatigue, diarrhea, hypertension, transaminitis and peripheral neuropathy. Treatment-related non-fatal bowel perforation, a known class effect, occurred in one patient. No significant association was noted between plasma levels of pazopanib and response.. The combination of pazopanib and metronomic paclitaxel was well-tolerated, demonstrating significant activity in metastatic melanoma. Further evaluation of this combination is warranted.

Topics: Administration, Metronomic; Adult; Aged; Aged, 80 and over; Antineoplastic Combined Chemotherapy Protocols; Female; Humans; Indazoles; Kaplan-Meier Estimate; Male; Melanoma; Middle Aged; Neoplasm Staging; Paclitaxel; Progression-Free Survival; Pyrimidines; Sulfonamides

There is a medical need for new drugs in patients with BRAF wild-type metastatic melanoma. Pazopanib is a multitarget tyrosine kinase inhibitor with antitumour and antiangiogenic activity.. The primary aim was to investigate the metabolic response to pazopanib monotherapy and pazopanib plus paclitaxel in patients with BRAF wild-type melanoma. Secondary end points were the early cytokine and chemokine profiles and histological findings.. Pazopanib (400 mg twice daily) was administered orally from days 1 to 10 and from days 14 to 70. An intravenous infusion with paclitaxel (150 mg m. Two patients failed screening and 17 were dosed. Of 67 adverse events, nine (13%) were grade 3 or 4. Five of 14 evaluable patients had a partial metabolic response at day 10 under pazopanib monotherapy. The response rate at day 70 under combined pazopanib-paclitaxel treatment was 0%. Immunohistochemistry revealed an increase of M2-like macrophages in nonresponders compared with responders. We observed a significant upregulation of five cytokines (CXCL1, CXCL2, CXCL13, CCL22 and SPP1) in responding vs. nonresponding lesions. Overall, the median progression-free survival was 70 days (range 5-331), which did not differ significantly between responders (148 days) and nonresponders (70 days, P = 0·17).. In this patient population pazopanib efficacy was limited. Response is associated with low M2-like macrophage density and increased expression of several chemokines.

Topics: Administration, Oral; Antineoplastic Combined Chemotherapy Protocols; Cytokines; Drug Administration Schedule; Female; Humans; Indazoles; Infusions, Intravenous; Male; Melanoma; Paclitaxel; Pyrimidines; Skin Neoplasms; Sulfonamides; Treatment Outcome; Up-Regulation

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

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

Metastatic melanoma has a median length of survival after diagnosis of 6-9 months. Unfortunately, the National Comprehensive Cancer Network clinical practice guidelines for treating stage IV, unresectable, metastatic melanoma are limited with regard to treatment options. Pazopanib (Votrient™) is FDA-approved for advanced soft tissue sarcoma and advanced renal cell carcinoma. Limited research exists for using pazopanib in the treatment of metastatic melanoma. We present five cases in which pazopanib was used in combination with paclitaxel ± carboplatin for treatment of unresectable, metastatic melanoma.

Topics: Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Carboplatin; Female; Humans; Indazoles; Male; Melanoma; Middle Aged; Pyrimidines; Sulfonamides

Pazopanib is an FDA approved Vascular Endothelial Growth Factor Receptor inhibitor. We previously reported that it also inhibits tumor cell B-Raf activity in an experimental brain metastatic setting. Here, we determine the effects of different B-Raf genotypes on pazopanib efficacy, in terms of primary tumor growth and anti-angiogenesis. A panel of seven human breast cancer and melanoma cell lines harboring different mutations in the Ras-Raf pathway was implanted orthotopically in mice, and tumor growth, ERK1/2, MEK1/2 and AKT activation, and blood vessel density and permeability were analyzed. Pazopanib was significantly inhibitory to xenografts expressing either exon 11 mutations of B-Raf, or HER2 activated wild type B-Raf; no significant inhibition of a xenograft expressing the common V600E B-Raf mutation was observed. Decreased pMEK staining in the responsive tumors confirmed that B-Raf was targeted by pazopanib. Interestingly, pazopanib inhibition of tumor cell B-Raf also correlated with its anti-angiogenic activity, as quantified by vessel density and area. In conclusion, using pazopanib, tumor B-Raf status was identified as a significant determinant of both tumor growth and angiogenesis.

Topics: Angiogenesis Inhibitors; Animals; Antineoplastic Agents; Breast Neoplasms; Cell Line, Tumor; Cell Proliferation; Female; Humans; Indazoles; MAP Kinase Signaling System; Melanoma; Mice; Neovascularization, Pathologic; Proto-Oncogene Proteins B-raf; Pyrimidines; Sulfonamides; Xenograft Model Antitumor Assays