A phase I study of sorafenib in combination with S-1 plus cisplatin in patients with advanced gastric cancer

Background

Sorafenib inhibits several receptor tyrosine kinases involved in tumor progression and angiogenesis. S-1, an oral fluorouracil antitumor drug, plus cisplatin (CDDP) is the standard regimen for advanced gastric adenocarcinoma (AGC) in Japan. The purpose of this phase I study was to evaluate the safety, pharmacokinetics, and preliminary efficacy of sorafenib in combination with S-1 plus CDDP.

Methods

Patients with histologically confirmed previously untreated AGC were evaluated for eligibility and treated with sorafenib (400 mg bid, days 1–35), S-1 (40 mg/m² bid, days 1–21), and CDDP (60 mg/m², day 8). Treatment was continued until disease progression or unacceptable toxicity. Pharmacokinetics for sorafenib, 5-FU, and CDDP were investigated in cycle 1.

Results

Thirteen patients were enrolled and received at least one dose of the study treatment. No specific or serious adverse event was newly reported in this study. Five patients had partial response and 8 had stable disease as the best response. Pharmacokinetic analysis showed no significant differences in the exposures of sorafenib when administered alone or in combination with S-1 and CDDP.

Conclusions

The present phase I study demonstrates the acceptable toxicity and preliminary efficacy of combined treatment with S-1, CDDP, and sorafenib.     

UGT1A1 polymorphism and hyperbilirubinemia in a patient who received sorafenib

Purpose

To report a single case of uridine glucuronosyltransferase 1A1 (UGT1A1) polymorphism and hyperbilirubinemia in a patient who received sorafenib.

Methods

A 63-year-old man with cirrhosis was diagnosed with hepatocellular carcinoma. His cirrhosis was categorized as Child-Pugh A, total bilirubin concentration was 24 μmol/L (normal range <20 μmol/L). The patient was enrolled in a phase I trial combination study of cyclophosphamide and doxorubicin combined with sorafenib.

Results

After a single infusion of doxorubicin and cyclophosphamide and 7 days of sorafenib, he presented with an elevated bilirubin concentration (48 μmol/L). Unconjugated bilirubin was 38 μmol/L and conjugated was 10 μmol/L. The patient was found to have one mutant allele (UGT1A1*28).

Conclusions

The isolated increase in serum bilirubin levels in our patient was probably due to sorafenib-induced UGT1A1 inhibition that manifested itself due both to the patient having one UGT1A1*28 allele and the presence of underlying liver disease. Bilirubin elevations in patients treated with sorafenib could indicate progression or drug toxicity; hence, these possibilities need to be ruled out. We would suggest that when patients develop hyperbilirubinemia while taking sorafenib for any indication, consideration be given to obtaining a fractionation of bilirubin and consideration of UGT1A1 genotyping in order to exclude a Gilbert’s syndrome as possible reason for the hyperbilrubinemia. Further studies are warranted to analyze the impact of sorafenib treatment on unconjugated bilirubin blood levels in patients with Gilbert’s syndrome.     

Pharmacokinetic interaction between sorafenib and prednisolone in a patient with hepatocellular carcinoma

Purpose

Sorafenib is primarily metabolized in the liver, by CYP3A4-mediated oxidation and UGT1A9-mediated glucuronidation. However, there is little information about the pharmacokinetic interaction of sorafenib. Here, we report a pharmacokinetic interaction between sorafenib and the CYP3A4 inducer prednisolone in a patient with hepatocellular carcinoma (HCC).

Patients and methods

The patient was a 72-year-old woman diagnosed with HCC. She was treated with sorafenib at 400 mg daily. On day 9, sorafenib was discontinued due to drug eruption. Nine months later, she was rechallenged with sorafenib at 400 mg daily concurrently with oral prednisolone. Prednisolone was started at 20 mg daily and was tapered by 5 mg every 14 days. We assessed the pharmacokinetics of sorafenib and its major metabolite M-2.

Results

The concentration of sorafenib was gradually increased following tapering of prednisolone. On day 56 after rechallenge, she developed G3 oral mucositis. At this time, serum trough concentrations of sorafenib and M-2 were at 5.9 and 1.1 μg/ml, respectively. Consequently, sorafenib dosage was reduced to 200 mg daily, and the oral mucositis was attenuated. The subsequent concentrations of sorafenib and M-2 obtained with a dose of 200 mg daily ranged from 1 to 3 μg/ml and from 0.1 to 0.4 μg/ml, respectively. Computed tomography scan showed a complete response of the liver tumor with no further recurrence of the rash.

Conclusions

We have demonstrated for the first time that prednisolone stimulates the sorafenib metabolism and that therapeutic drug monitoring could be useful during sorafenib therapy.     

Radiologic Complete Response with Sirolimus and Sorafenib in a Hepatocellular Carcinoma Patient who Relapsed After Orthotopic Liver Transplantation

Background

No standard therapies have been established for the treatment of recurrent hepatocellular carcinoma (HCC) after liver transplantation.

Discussion

Sirolimus is a mTOR inhibitor which has been used as an immunosuppressive medication in patients who are at high risk of tumor reoccurrence after liver transplantation. Sorafenib is a multikinase inhibitor approved for the treatment of advanced HCC. However the role of sorafenib in patients with HCC reoccurrence after liver transplantation is unclear.

Results

Combination of sirolimus and sorafenib appears to have synergistic effect when treating HCC in preclinical settings. We report a case of a post-liver transplant patient treated with sorafenib and sirolimus for hepatic HCC recurrence who exhibited complete radiologic response after 5 months of therapy.     

Strong enhancement by IGF1-R antagonists of hepatocellular carcinoma cell migration inhibition by Sorafenib and/or vitamin K1

Purpose

Emerging evidence indicates that combining Sorafenib with vitamin K1 (VK1) may result in a synergistic inhibition of hepatocellular carcinoma (HCC) cell migration and proliferation. Despite this synergy, its benefits may be limited due to drug resistance resulting from cross-talk with the tumor microenvironment. Insulin-like growth factor-1 (IGF1) signaling acts as an important modulator of HCC cell growth, motility and drug resistance. Therefore, we aimed to explore the effects of Sorafenib in combination with VK1 and/or IGF1-R antagonists on HCC cells.

Methods

Scratch wound migration assays were performed to assess the motility of HCC-derived PLC/PRF/5, HLF and Hep3B cells. The synergistic, additive or antagonistic effects of Sorafenib, VK1 and IGF1-R antagonists on HCC cell motility were assessed using CompuSyn software. The effects mediated by these various compounds on HCC cytoskeleton organization were evaluated using DyLight 554 Phalloidin staining. Proliferation and migration-associated signaling pathways were analyzed in PLC/PRF/5 cells using Erk1/2 and Akt activation kits and Western blotting (Mek, JNK, Akt, Paxillin and p38), respectively.

Results

The effects of the IGF1-R antagonists GSK1838705A and OSI-906 on HCC cell migration inhibition after Sorafenib and/or VK1 administration, individually or in combination, were evaluated. We found a synergistic effect in PLC/PRF/5, HLF and Hep3B cells for combinations of fixed doses of GSK1838705A or OSI-906 together with different doses of Sorafenib and/or VK1. The levels of synergy were found to be stronger at higher Sorafenib and/or VK1 concentrations and lower or absent at lower concentrations, with some variation among the different cell lines tested. In addition, we found that in PLC/PRF/5 and HLF cells IGF1-R blockage strongly enhanced the reduction and redistribution of F-actin induced by Sorafenib and/or VK1 through alterations in the phosphorylation levels of some of the principal proteins involved in the MAPK signaling cascade, which is essential for cell migration.

Conclusions

Our results indicate that modulation of the efficacy of Sorafenib through combinations with VK1 and/or IGF1-R antagonists results in synergistic inhibition of HCC cell migration.

     

Sorafenib plus octreotide is an effective and safe treatment in advanced hepatocellular carcinoma: multicenter phase II So.LAR. study

Purpose

Advanced hepatocellular carcinoma (HCC) not eligible for local therapies has limited chances of cure. Sorafenib is a multikinase inhibitor with proven activity in advanced HCC. Octreotide is used in this setting with conflicting results. Treatment with sorafenib and long-acting octreotide was tested in advanced HCC to evaluate safety and activity.

Methods

Fifty patients with advanced HCC, Child-Pugh A or B, received sorafenib at a dosage of 800 mg/day for 28 days with a following week of rest and long-acting octreotide at a dose of 40 mg, administered every 28 days.

Results

All patients were assessable for safety and efficacy. Sixteen patients out of 50 (34%) were naïve from other therapies, while all the others were previously treated with local and/or systemic treatments. We achieved 5 partial responses (10%), 33 stable diseases (66%) and 12 progressions of disease (24%). Median time to progression was 7.0 months (95% CI, 3.0–10.9 months), and median overall survival was 12 months (95% CI, 6.3–17.4 months). Treatment was well tolerated. Diarrhoea (6%) and hypertension (4%) were the most frequent grade 3 toxicities.

Conclusions

Our data suggest that the combination between sorafenib and long-acting octreotide is active and well tolerated in patients with advanced HCC and could represent another efficacious chance for the management of this population.     

Benchmarking effects of mTOR, PI3K, and dual PI3K/mTOR inhibitors in hepatocellular and renal cell carcinoma models developing resistance to sunitinib and sorafenib

Purpose

To evaluate first-generation rapamycin analogs (everolimus, temsirolimus, and rapamycin) and second-generation drugs inhibiting mTOR kinase (AZD-8055), PI3K (BKM-120) or both (BEZ-235 and GDC-0980) in hepatocellular carcinoma (HCC) and renal cell carcinoma (RCC) cells characterized for acquired resistance to sorafenib or sunitinib.

Methods

Anti-proliferative (MTT assay) and cell signaling (Western blot) effects of rapamycin analogs (1–20 μM) and second-generation drugs (0.03–20.0 μM) were assessed in human HCC SK-HEP1, RCC 786-0, and sorafenib- (SK-Sora) or sunitinib-resistant (786-Suni) cells.

Results

In SK-HEP1 cells displaying high PTEN and Bcl2 expression, rapamycin analogs had poor anti-proliferative effects. However, SK-Sora cells were more sensitive to rapamycin analogs (≥1 μM) than SK-HEP1 cells. In 786-0 cells, lacking PTEN and Bcl2 expression, ≥1 μM rapamycin analogs blocked mTORC1 signaling, transiently activated Akt, and inhibited cell proliferation. Protracted sunitinib exposure in 786-Suni cells yielded an increase in p27 expression and a decreased sensitivity to rapamycin analogs, although mTORC1 function could be inhibited with rapamycin analogs. Second-generation drugs induced more potent growth inhibition than rapamycin analogs at concentrations >0.03 μM in parental cells, SK-Sora, and 786-Suni cells. Growth inhibitory concentrations of these new drugs also blocked mTORC1 downstream targets.

Conclusions

Rapamycin analogs inhibited mTORC1 downstream targets and yielded anti-proliferative effects in HCC and RCC cells. Second-generation drugs also appeared to be potent inhibitors of mTORC1 signaling; however, they appeared to be far more potent in inhibiting cellular proliferation in parental HCC and RCC cells and in cells developing resistance to sorafenib or sunitinib.     

Safety, efficacy and pharmacokinetics of S-1 in a hemodialysis patient with advanced gastric cancer

Purpose

The safety and efficacy of S-1 in hemodialysis patients have not been established. We evaluated the safety and efficacy and pharmacokinetics of S-1 in a hemodialysis patient with advanced gastric cancer.

Patient

A 66-year-old Japanese man with chronic renal failure, who had undergone hemodialysis three times a week for 3 years. Based on the diagnosis of stage IV gastric cancer, S-1 therapy was started. S-1 was administered 11 times at a daily dose of 23.5 mg/m² (40 mg/body) after hemodialysis, followed by a rest. One course was a period of 28 days. Blood samples were obtained after the first administration of S-1 and before beginning the fourth course. The concentration of 5-FU was determined by high-performance liquid chromatography.

Results

Area under the concentration–time curve (AUC) of 5-FU was 2647.2 ng h/mL after administration of S-1 of 23.5 mg/m² (40 mg/body). During the S-1 treatment, serious adverse events such as neutropenia were not observed; however, decreases in hemoglobin level were observed (grade 3). The treatment was well tolerated. After the second course of chemotherapy, the primary lesion showed a partial response and lymph node metastases and liver metastases showed stable disease.

Conclusions

Our results suggest that S-1 is an important treatment option for patients with hemodialysis with advanced gastric cancer.     

Orally administered S-1 suppresses circulating endothelial cell counts in metastatic breast cancer patients

Background

S-1 is an oral cytotoxic preparation that contains tegafur. Gamma-butyrolactone (GBL) is a metabolite of tegafur that is known to suppress vascular endothelial growth factor (VEGF)-mediated angiogenic activity. The aim of this study was to determine the change in circulating endothelial cell (CEC) counts, GBL levels, and angiogenesis-related factors during S-1 administration in metastatic breast cancer (MBC) patients.

Methods

Patients with HER2-negative MBC were eligible. S-1 was administered orally twice daily in a 4 week on/2 week off cycle until disease progression or unacceptable toxicity occurred. Blood was collected on the following: days 1, 43, 85 (before each cycle of S-1 administration), days 15, 57 (1 h after S-1 administration), and day 29. The CellSearch^® system was used to count the CECs. The gas chromatographic–mass spectrometric method was used to measure plasma GBL and 5-FU levels. Levels of VEGF were assayed by enzyme-linked immunosorbent assay.

Results

A total of 18 patients were enrolled. The plasma GBL levels on days 15 and 57 were 41.3 ± 15.8 and 41.0 ± 11.2 ng/mL, respectively. The CEC levels decreased on day 15, and significantly low levels were maintained until day 85 (P = 0.002 vs day 1). The plasma VEGF levels significantly decreased on day 15 (P = 0.012 vs day 1) and had a tendency to decrease until day 57.

Conclusions

This exploratory study showed that GBL levels increased, VEGF levels decreased, and CEC levels were suppressed during S-1 administration. S-1 appears to have anti-angiogenic activity.     

Safety and pharmacokinetics of S-1 in a recurrent colon cancer patient with chronic myeloid leukemia treated with dasatinib: a case report

Purpose

The safety of S-1 in recurrent colorectal cancer patients with chronic myeloid leukemia (CML) treated with dasatinib has not been established. We evaluated the safety and pharmacokinetics of S-1 in a recurrent colon cancer patient with CML treated with dasatinib.

Patient

A 70-year-old man had undergone surgery three times for sigmoid colon cancer and recurrence. Systemic chemotherapy with S-1 plus oxaliplatin plus bevacizumab as a clinical trial had already been administered because of metastatic colon cancer. The patient’s medical history was CML, and he had been receiving dasatinib treatment (100 mg once daily). Based on the diagnosis of unresectable and multiple metastases, S-1 monotherapy was started. S-1 (120 mg/day) was taken for 28 consecutive days, followed by a 14-day rest. Blood samples were obtained before and after the first administration of S-1. The plasma pharmacokinetics of S-1 were comparable to a pharmacokinetics study of S-1.

Results

The area under the plasma concentration–time curve (AUC_0–8) of tegafur (FT), 5-chloro-2, 4-dihydroxypyridine (CDHP), oxonate (Oxo), and 5-fluorouracil (5-FU) was 4,309.2, 716.3, 86.8, and 492.75 ng h/mL, respectively, after S-1 administration. The pharmacokinetics of FT, CDHP, Oxo, and 5-FU after treatment with S-1 were not significantly different from a phase I pharmacokinetics study of S-1. During treatment with S-1 and dasatinib, CML relapse and serious myelosuppression were not observed.

Conclusions

Our report suggests that S-1 is an important treatment option for recurrent colorectal cancer in patients with CML treated with dasatinib.     

Sorafenib blocks the RAF/MEK/ERK pathway, inhibits tumor angiogenesis, and induces tumor cell apoptosis in hepatocellular carcinoma model PLC/PRF/5

Angiogenesis and signaling through the RAF/mitogen-activated protein/extracellular signal-regulated kinase (ERK) kinase (MEK)/ERK cascade have been reported to play important roles in the development of hepatocellular carcinomas (HCC). Sorafenib (BAY 43-9006, Nexavar) is a multikinase inhibitor with activity against Raf kinase and several receptor tyrosine kinases, including vascular endothelial growth factor receptor 2 (VEGFR2), platelet-derived growth factor receptor (PDGFR), FLT3, Ret, and c-Kit. In this study, we investigated the in vitro effects of sorafenib on PLC/PRF/5 and HepG2 HCC cells and the in vivo antitumor efficacy and mechanism of action on PLC/PRF/5 human tumor xenografts in severe combined immunodeficient mice. Sorafenib inhibited the phosphorylation of MEK and ERK and down-regulated cyclin D1 levels in these two cell lines. Sorafenib also reduced the phosphorylation level of eIF4E and down-regulated the antiapoptotic protein Mcl-1 in a MEK/ERK-independent manner. Consistent with the effects on both MEK/ERK-dependent and MEK/ERK-independent signaling pathways, sorafenib inhibited proliferation and induced apoptosis in both HCC cell lines. In the PLC/PRF/5 xenograft model, sorafenib tosylate dosed at 10 mg/kg inhibited tumor growth by 49%. At 30 mg/kg, sorafenib tosylate produced complete tumor growth inhibition. A dose of 100 mg/kg produced partial tumor regressions in 50% of the mice. In mechanism of action studies, sorafenib inhibited the phosphorylation of both ERK and eIF4E, reduced the microvessel area (assessed by CD34 immunohistochemistry), and induced tumor cell apoptosis (assessed by terminal deoxynucleotidyl transferase-mediated nick end labeling) in PLC/PRF/5 tumor xenografts. These results suggest that the antitumor activity of sorafenib in HCC models may be attributed to inhibition of tumor angiogenesis (VEGFR and PDGFR) and direct effects on tumor cell proliferation/survival (Raf kinase signaling-dependent and signaling-independent mechanisms).     

Safety and anti-tumor activity of sorafenib (Nexavar®) in combination with other anti-cancer agents: a review of clinical trials

Purpose

Sorafenib (Nexavar^®) is an oral multi-kinase inhibitor that inhibits Raf serine/threonine kinases and receptor tyrosine kinases involved in tumor growth and angiogenesis. Sorafenib has demonstrated preclinical and clinical activity against several tumor types, as a monotherapy and in combination with other anti-cancer agents.

Methods

This review summarizes the safety, pharmacokinetics, and anti-tumor activity of sorafenib combined with other targeted agents or cytotoxics from a series of Phase I/II trials in approximately 600 patients with advanced solid tumors.

Results

Sorafenib in combination with other agents was generally well tolerated, and most adverse events were mild to moderate in severity. Frequent drug-related toxicities were dermatologic, gastrointestinal, or constitutional. Most trials supported sorafenib 400 mg bid as the recommended dose for combination. Sorafenib generally had little effect on the pharmacokinetics of coadministered agents and vice versa. Preliminary anti-tumor activity was observed; overall disease control rates (partial response plus stable disease) ranged from 33 to 92%. Particularly promising activity was observed in patients with melanoma, hepatocellular carcinoma, and non-small-cell lung cancer receiving sorafenib plus paclitaxel/carboplatin, doxorubicin, and gefitinib, respectively.

Conclusions

Sorafenib demonstrated a good safety profile and encouraging anti-tumor effects when coadministered with other agents in patients with advanced solid tumors.     

Enhanced 5-fluorouracil cytotoxicity in high cyclooxygenase-2 expressing colorectal cancer cells and xenografts induced by non-steroidal anti-inflammatory drugs via downregulation of dihydropyrimidine dehydrogenase

Purpose

To prove that 5-FU cytotoxicity could be increased by combination with low-dose non-steroidal anti-inflammatory drugs (NSAIDs) (indomethacin or NS-398) in high cyclooxygenase-2- (COX-2) expressing cells and xenografts through the modulation of dihydropyrimidine dehydrogenase (DPD) mRNA expression and/or enzyme activity.

Methods

HT-29 cells were grown on collagen IV coated plates (HT-29-C). The antiproliferative effect of 5-fluorouracil (5-FU) ± NSAIDs was examined on non-COX-2 expressing HT-29 and COX-2-expressing HT-29-C cells by sulphorhodamine B assay. The COX-2 and DPD expressions were visualized by immunofluorescent staining, and prostaglandin E₂ levels were measured by ELISA kit. The HT-29 xenograft was established in SCID mice and treated with 5-FU ± NSAIDs for 5 days. The tumor volume, enzyme activity, and DPD mRNA expression were investigated by caliper, radioenzymatic method, and real-time RT-PCR, respectively. The drug interaction was calculated for both combinations (5-FU + indomethacin and 5-FU + NS-398).

Results

Collagen IV up-regulated significantly the COX-2 and DPD mRNA, and protein expressions, and also their enzyme activities in HT-29 cells. NSAIDs enhanced in a synergistic manner the cytotoxic effect of 5-FU treatment both in vitro and in vivo. Downregulation of DPD was observed after 5-FU monotherapy, but the combined effect of NSAIDs and 5-FU on DPD mRNA expression, and enzyme activity was superior to the effect of 5-FU alone.

Conclusions

Since 5-FU + NSAID treatment can alter the DPD enzyme activity resulting in an enhanced cytotoxic effect, further studies in clinical practice are warranted.     

Phase I study of sorafenib in combination with everolimus (RAD001) in patients with advanced neuroendocrine tumors

Purpose

Sorafenib and everolimus are both active against neuroendocrine tumors (NET). Because of potential synergy between VEGF pathway and mTOR inhibitors, we performed a phase I study to evaluate the safety and feasibility of combining sorafenib and everolimus in patients with advanced NET.

Methods

Patients were treated with everolimus 10 mg daily in combination with sorafenib (dose level 1: 200 mg twice daily; dose level 2: 200 mg per morning, 400 mg per evening) using standard phase I dose escalation design. Dose-limiting toxicity (DLT) was defined within the first cycle (28 days) of therapy. Treatment was continued until tumor progression, unacceptable toxicity, or withdrawal of consent. Twelve additional patients were treated at the maximum tolerated dose (MTD) level to further characterize safety and a preliminary assessment of activity.

Results

One patient in Cohort 1 experienced DLT (grade 3 skin rash); the cohort was expanded to 6 patients with no further DLTs. All 3 patients in Cohort 2 experienced DLT, consisting of thrombocytopenia, hand–foot skin reaction, and rash/allergic reaction. Sorafenib 200 mg twice daily in combination with everolimus 10 mg daily was established as the MTD. Independently reviewed best objective responses revealed that 62 % of patients had some degree of tumor shrinkage. By RECIST, we observed partial response in 1 patient, stable disease in 13 patients, and progressive disease in 3 patients.

Conclusion

Sorafenib 200 mg twice daily with everolimus 10 mg daily represents the MTD of this combination in patients with advanced NET. While the combination is active, toxicity concerns may preclude more widespread use.     

Sorafenib for non-selected patient population with advanced hepatocellular carcinoma: efficacy and safety data according to liver function

Objective

Sorafenib is the standard treatment of patients with advanced hepatocellular carcinoma, regardless of the liver functional reserve. We present a single institutional series of Child–Pugh A and Child–Pugh B patients treated with sorafenib with the aim to establish the efficacy and safety of sorafenib in patients of daily clinical conditions and to compare these results between Child–Pugh A and Child–Pugh B patients.

Materials and methods

A total of 51 patients were treated with sorafenib 400 mg/12 h until disease progression or unacceptable toxicity.

Results

The median progression-free survival and overall survival for the overall population were 3.5 and 8.2 months, respectively, with a 1-year survival rate of 27 %. Overall survival was significantly longer for patients Child–Pugh A compared with those with Child–Pugh B liver function (8.7 vs. 4.7 months, respectively). The most common adverse events were fatigue (62.7 %), diarrhea (58 %), hypertension (31.3 %), and hand–foot syndrome (31.3 %), and in most cases grade 1 or 2 according to the NCI-CTC 3.0. Grade 4 liver-related events occurred mainly in Child–Pugh B patients with decompensated cirrhosis at the time of sorafenib initiation (54.5 % of that group).

Discussion

The benefit of sorafenib in Child–Pugh B patients, if exist, may be limited by frequent liver-related events, especially in decompensated patients, and then, toxicity and impact in quality of life should be carefully monitored.     

Effects of sorafenib combined with low-dose interferon therapy for advanced hepatocellular carcinoma: a pilot study

Background

Sorafenib is a standard of care for advanced hepatocellular carcinoma (HCC). An in vitro study showed the synergistic effects of sorafenib and interferon for HCC. To clarify the efficacy, combination therapy with sorafenib and interferon was performed for patients with advanced HCC.

Methods

Pegylated interferon α-2a was administered every 2 weeks for the initial 4 weeks. Subsequently, it was combined with sorafenib. We evaluated the anti-tumor effect and biomarkers during treatment period.

Results

The subjects were 13 patients with advanced HCC complicated by hepatitis C virus (HCV)-related liver cirrhosis. A partial response, stable disease and progressive disease were noted in 4, 6, and 3 patients, respectively. The response rate, the disease control rate, the mean time to progression and the median survival time (MST) were 30.8 % (4/13), 76.9 % (10/13), 12.2 months, and 17.5 months, respectively. In 8 Child-Pugh class A and 5 Child-Pugh class B patients, the MST was 22.0 and 11.0 months, respectively (p = 0.001). In plasma vascular endothelial growth factor (VEGF), serum alpha-fetoprotein (AFP), AFP-L3, a protein induced by vitamin K absence or antagonist-II (PIVKA II), and hepatocyte growth factor (HGF), there was no pretreatment factor and no biomarker during the combination therapy to predict therapeutic effect in the present study.

Conclusions

The results of this study suggest that combination therapy with sorafenib and interferon could be effective and safe in advanced HCC patients with HCV-related liver cirrhosis.

     

Sorafenib (BAY 43-9006) inhibits tumor growth and vascularization and induces tumor apoptosis and hypoxia in RCC xenograft models

Purpose

New research findings have revealed a key role for vascular endothelial growth factor (VEGF) in the stimulation of angiogenesis in clear cell renal carcinoma (RCC) which is a highly vascularized and treatment-resistant tumor. Sorafenib (BAY 43-9006, Nexavar^®) is a multi-kinase inhibitor which targets receptor tyrosine and serine/threonine kinases involved in tumor progression and tumor angiogenesis. The effect of sorafenib on tumor growth and tumor histology was assessed in both ectopic and orthotopic mouse models of RCC.

Methods

Sorafenib was administered orally to mice bearing subcutaneous (SC, ectopic) or sub-renal capsule (SRC, orthotopic) tumors of murine (Renca) or human (786-O) RCC. Treatment efficacy was determined by measurements of tumor volume and tumor growth delay. In mechanism of action studies, using the 786-O and Renca RCC tumor models, the effect of sorafenib was assessed after dosing for 3 or 5 days in the SC models and 21 days in the SRC models. Inhibition of tumor angiogenesis was assessed by measuring level of CD31 and α-smooth muscle actin (αSMA) staining by immunohistochemistry (IHC). The effect of sorafenib on MAPK signaling, cell cycle progression and cell proliferation was also assessed by IHC by measuring levels of phospho-ERK, phospho-histone H3 and Ki-67 staining, respectively. The extent of tumor apoptosis was measured by terminal deoxynucleotidyl transferase-mediated nick-end labeling (TUNEL) assays. Finally, the effects of sorafenib on tumor hypoxia was assessed in 786-O SC model by injecting mice intravenously with pimonidazole hydrochloride 1 h before tumor collection and tumor sections were stained with a FITC-conjugated Hypoxyprobe antibody.

Results

Sorafenib produced significant tumor growth inhibition (TGI) and a reduction in tumor vasculature of both ectopic and orthotopic Renca and 786-O tumors, at a dose as low as 15 mg/kg when administered daily. Inhibition of tumor vasculature was observed as early as 3 days post-treatment, and this inhibition of angiogenesis correlated with increased level of tumor apoptosis (TUNEL-positive) and central necrosis. Consistent with these results, a significant increase in tumor hypoxia was also observed 3 days post-treatment in 786-O SC model. However, no significant effect of sorafenib on phospho-ERK, phospho-histone H3 or Ki-67 levels in either RCC tumor model was observed.

Conclusion

Our results show the ability of sorafenib to potently inhibit the growth of both ectopically- and orthotopically-implanted Renca and 786-O tumors. The observed tumor growth inhibition and tumor stasis or stabilization correlated strongly with decreased tumor angiogenesis, which was due, at least in part, to inhibition of VEGF and PDGF-mediated endothelial cell and pericyte survival. Finally, sorafenib-mediated inhibition of tumor growth and angiogenesis occurred at concentrations equivalent to those achieved in patients in the clinic.     

Synergistic effect of 5-fluorouracil and the flavanoid oroxylin A on HepG2 human hepatocellular carcinoma and on H22 transplanted mice

Aim

To investigate the synergistic inhibitory effects of the combination of 5-fluorouracil (5-FU) with the natural flavanoid oroxylin A on human hepatocellular carcinoma cells HepG2 in vitro and on transplanted murine hepatoma 22 (H₂₂) tumors in vivo and the preliminary mechanisms.

Methods

The inhibitory effects of 5-FU combined with the natural flavanoid oroxylin A in vitro were detected by MTT assay and the effects in vivo were investigated by transplanted H₂₂ mice model. DAPI staining and Annexin V/propidium iodide (PI) double staining were used to detect the cell morphological changes and apoptosis. The mRNA levels of thymidine synthetase (TS) and dihydropyrimidine dehydrogenase (DPD) in HepG2 cells after oroxylin A and 5-FU combination treatment were observed by quantitative real-time PCR. Western blotting assay was used to reveal the expressions of apoptotic-inducing proteins P53, cleaved PARP, COX-2, Bcl-2, and pro-caspase3.

Results

Oroxylin A in combination with 5-FU presented synergistic effect (CI < 1) on HepG2 cells in vitro when the inhibitory rate was higher than 7.5%. The inhibitory rate on H₂₂ murine solid tumor in vivo in the combination group was higher than monotherapy. 5-FU combined with oroxylin A exerted stronger apoptotic induction in HepG2 cells than either single drug treatment. Quantitative real-time PCR discovered the downregulation of TS mRNA and DPD mRNA in HepG2 cells after combination treatment. Western blotting assay revealed oroxylin A enhanced 5-FU-induced apoptosis in HepG2 cells by elevating the expressions of apoptotic-inducing proteins P53 and cleaved PARP and decreasing the expression of apoptotic-inhibitory proteins COX-2, Bcl-2, and pro-caspase3.

Conclusion

The anti-hepatocellular carcinoma effects in vitro and in vivo of 5-FU and oroxylin A combinations were synergistic and oroxylin A increased the sensitivity of HepG2 cells to 5-FU by modulating the metabolic enzymes of 5-FU and apoptotic-related proteins.     

Comparison of safety and efficacy of S-1 monotherapy and S-1 plus cisplatin therapy in elderly patients with advanced gastric cancer

Background

Although S-1 plus cisplatin (SP) therapy is recognized as the standard treatment for advanced gastric cancer (AGC) in Japan, its safety and efficacy in elderly patients have not been investigated sufficiently.

Methods

We retrospectively reviewed the data of 58 patients with AGC selected from 82 consecutive patients who were ≥70 years old and were treated with SP or S-1 monotherapy as the first-line therapy. In SP, S-1 (40 mg/m², bid) was administered for 3 weeks and cisplatin (60 mg/m²) on day 8, every 5 weeks. In S-1 monotherapy, S-1 (40 mg/m², bid) was administered for 4 weeks, every 6 weeks.

Results

SP and S-1 was administered in 21 and 37 patients, respectively. There were some differences in patient characteristics between the treatment groups, such as histological type (P = 0.16); the presence of liver metastasis (P = 0.07); and the presence of peritoneal metastasis (P = 0.02). The incidences of grade 3/4 hematological toxicities were 57% (12/21) in the SP and 35% (13/37) in the S-1 group (P = 0.17). Those of non-hematological toxicities were 14% (3/21) and 14% (5/37) for anorexia, 10% (2/21) and 14% (5/37) for fatigue, and 5% (1/21) and 5% (2/37) for nausea in the SP and S-1 groups, respectively. Median progression-free survival and median overall survival in the SP and S-1 groups were 5.0 and 5.2 months, and 14.4 and 10.9 months, respectively.

Conclusion

SP and S-1 therapy were both feasible in elderly patients, though there is the risk of a high incidence of hematological toxicities.