Phase II study of Erlotinib (OSI-774) in patients with advanced hepatocellular cancer

Phase I study of sorafenib in Japanese patients with hepatocellular carcinoma

Sorafenib is an orally active multikinase inhibitor that targets serine and threonine, and tyrosine kinases that are involved in tumor-cell signal transduction and tumor angiogenesis. This phase I trial was conducted to evaluate the pharmacokinetics (PK), safety, and preliminary efficacy of sorafenib in Japanese patients with hepatocellular carcinoma (HCC) with underlying liver dysfunction. Patients with unresectable HCC, Child-Pugh status A or B, and adequate organ functions were treated. A single dose of sorafenib was administered, followed by a 7-day wash-out period, after which patients received either sorafenib 200 mg (cohort 1) or 400 mg (cohort 2) twice daily. The PK were investigated after a single dose and during steady state. The efficacy was evaluated using the Response Evaluation Criteria in Solid Tumors. A total of 27 patients were evaluated for PK, safety, and efficacy. Although both area under the concentration-time curve for 0-12 h and maximal concentration at steady state were slightly lower in Child-Pugh B patients than in Child-Pugh A patients, the difference was not considered to be clinically relevant. Common adverse drug events included elevated lipase, amylase, rash or desquamation, diarrhea, and hand-foot skin reaction. A dose-limiting toxicity of hand-foot skin reaction was observed in one patient (cohort 2). Among the 24 patients evaluable for tumor response, one patient (4%) achieved a partial response, 20 (83%) had stable disease, and three (13%) had progressive disease. Sorafenib demonstrated a favorable tolerability and safety profile in Japanese HCC patients. Moreover, promising preliminary antitumor activity has been observed. Finally, there were no clinically relevant differences in PK between Child-Pugh A and B patients.

From molecular biology to targeted therapies for hepatocellular carcinoma: the future is now

Hepatocellular carcinoma (HCC) is characterized as a highly chemoresistant cancer with no effective systemic therapy. Despite surgical or locoregional therapies, prognosis remains poor because of high tumor recurrence or tumor progression, and currently there are no well-established effective adjuvant therapies. The molecular biology of carcinogenesis and tumor progression of HCC has been increasingly understood with intense research in recent years. Several important intracellular signaling pathways such as the Ras/Raf/Mek/Erk pathway and PI3k/Akt/mTOR pathway have been recognized, and the role of several growth factors and angiogenic factors such as EGF and VEGF has been confirmed. Effective agents targeting these molecular abnormalities have been developed and widely tested in preclinical studies of HCC cell lines or xenograft models. Several agents have entered clinical trials in HCC patients, and recent data indicated that a multikinase inhibitor targeting Ras kinase and VEGFR-2, sorafenib, is effective in prolonging survival of patients with advanced HCC. The management of advanced HCC is entering the era of molecular targeting therapy, which is of particular significance for HCC in view of the lack of existing effective systemic therapy for this cancer.

Phase 2 study of cetuximab in patients with advanced hepatocellular carcinoma

BACKGROUND

Epidermal growth factor receptor (EGFR) and ligand expression is frequently seen in hepatocellular carcinoma (HCC). A phase 2 study was performed with cetuximab, a chimeric monoclonal antibody that binds specifically to EGFR, in patients with advanced HCC.

METHODS

Eligibility criteria included unresectable or metastatic measurable HCC, an Eastern Cooperative Oncology Group performance status <or=2, Cancer of the Liver Italian Program (CLIP) score <or=3, and adequate organ functions. The initial dose of cetuximab was 400 mg/m(2) given intravenously followed by weekly intravenous infusions at 250 mg/m(2). Each cycle was defined as 6 consecutive weekly treatments. EGFR expression was assayed by immunohistochemistry and trough serum concentrations of cetuximab were determined during the first cycle.

RESULTS

Thirty patients were enrolled and assessable for efficacy and toxicity. No responses were seen. Five patients had stable disease (median time, 4.2 months; range, 2.8-4.2 months). The median overall survival was 9.6 months (95% confidence interval [CI], 4.3-12.1 months) and the median progression-free survival (PFS) was 1.4 months (95% CI, 1.2-2.6 months). The treatment was generally well tolerated. No treatment-related grade 4-5 toxicities occurred. Grade 3 (according to the National Cancer Institute's Common Terminology Criteria for Adverse Events [version 3.0]) aspartate aminotransferase, hypomagnesemia, and fever without neutropenia were noted in 1 patient (3.3%) each. On Week 6 of Cycle 1, arithmetic mean serum cetuximab concentrations for patients with Child-Turcotte-Pugh (CTP) A and CTP B disease were 47.6 mcg/mL and 66.9 mcg/mL, respectively.

CONCLUSIONS

Although cetuximab could be safely administered with tolerable toxicity profiles, it demonstrated no antitumor activity in HCC in this phase 2 study. Cetuximab trough concentrations were not notably altered in patients with mild to moderate hepatic dysfunction.

Laminin-5 stimulates hepatocellular carcinoma growth through a different function of alpha6beta4 and alpha3beta1 integrins

Hepatocellular carcinoma (HCC) growth severely affects prognosis. Ki-67, a known marker of cell proliferation, is a negative prognostic factor in HCC. Growth factors such as the epidermal growth factor (EGF) induce HCC cell proliferation but do not explain the great heterogeneity of HCC growth. Laminin-5 (Ln-5) is an extracellular matrix protein (ECM) present in the tissue microenvironment of HCC. The two main receptors for Ln-5, integrins alpha3beta1 and alpha6beta4, are expressed on the cell surface of HCC cells. The aim of this study is to investigate an alternative mechanism of HCC growth whereby Ln-5 promotes HCC cell proliferation through alpha3beta1 and alpha6beta4. HCC tissues containing Ln-5 display a larger diameter and higher number of positive cells for Ki-67, a well known proliferative index, as determined by double immunofluorescence staining and real-time PCR on microdissected tissues. In vitro, Ln-5, but not collagen I, collagen IV or fibronectin, induces proliferation as much as EGF does, via Erk phosphorylation as a consequence of beta4 integrin phosphorylation. However, the two HCC cell lines do not proliferate in presence of Ln-5 despite beta4 integrin and Erk1/2 activation. After transfection with alpha3 integrin, in the presence of Ln-5 one of these HCC cell lines acquires a proliferative activity whereas one of the proliferative HCC cell lines, knocked-down for alpha3 integrin, loses its proliferative activity.

CONCLUSIONS

Our study suggests a new mechanism of HCC growth whereby Ln-5 stimulates proliferation via a different function of alpha6beta4 and alpha3beta1.

Phase 2 study of erlotinib in patients with unresectable hepatocellular carcinoma

BACKGROUND

Growth factor overexpression, including epidermal growth factor receptor (EGFR) expression, is common in hepatocellular cancers. Erlotinib is a receptor tyrosine kinase inhibitor with specificity for EGFR. The primary objective of this study was to determine the proportion of hepatocellular carcinoma (HCC) patients treated with erlotinib who were alive and progression-free (PFS) at 16 weeks of continuous treatment.

METHODS

Patients with unresectable HCC, no prior systemic therapy, performance status (PS) of 0, 1, or 2, and Childs-Pugh (CP) cirrhosis A or B received oral erlotinib 150 mg daily for 28-day cycles. Tumor response was assessed every 2 cycles by using Response Evaluation Criteria in Solid Tumors (RECIST; National Cancer Institute Cancer Therapy Evaluation Program, Bethesda, Md) criteria. Patients accrued to either "low" or "high" EGFR expression cohorts; each cohort had stopping rules applied when there was a lack of efficacy.

RESULTS

Forty HCC patients were enrolled. Median age was 64 years (range, 33-83 years), sex distribution was 32 males and 8 females, performance scores were 40% PS 0, 55% PS 1, Childs-Pugh distribution was 75% A and 20% B. There were no complete or partial responses; however, 17 of 40 patients achieved stable disease at 16 weeks of continuous therapy. The PFS at 16 weeks was 43%, and the median overall survival (OS) was 43 weeks (10.75 months). No patients required dose reductions of erlotinib. No correlation between EGFR expression and outcome was found.

CONCLUSIONS

Results of this study indicated that single-agent erlotinib is well tolerated and has modest disease-control benefit in HCC, manifested as modestly prolonged PFS and OS when compared with historical controls.

Multicentre phase II trial of capecitabine plus oxaliplatin (XELOX) in patients with advanced hepatocellular carcinoma: FFCD 03-03 trial

Evaluation of new drug combinations is needed to improve patients' prognosis in advanced hepatocellular carcinoma (HCC). The purpose of this study was to evaluate the safety and efficacy of the capecitabine–oxaliplatine combination (XELOX) in HCC patients. First-line chemotherapy with XELOX regimen consisting of a 3-week cycle of intravenous oxaliplatin (130 mg m⁻²) on Day 1, and oral capecitabine twice daily from Days 1–14 (1000 mg m⁻²) was administered in patients with measurable, unresectable HCC. Fifty patients (male, 88%; median age, 68 years) received a total of 295 cycles (median, 6) of treatment. Disease control (three partial responses, 29 stable diseases) rate was 72% (95% CI 57–83%). Median overall and median progression-free (PFS) survival was 9.3 months and 4.1 months, respectively. Progression-free survival rates at 6 and 12 months were 38% (95% CI 26–52%) and 14% (95% CI 7–26%), respectively. Main grade 3–4 drug-related toxicities included diarrhoea (16%), elevation of aminotransferases and/or bilirubin (16%), thrombocytopenia (12%), and neurotoxicity (6%). Capecitabine plus oxaliplatin regimen showed modest anti-tumour activity with tolerable toxicities in patients with advanced HCC. However, the manageable toxicity profile and the encouraging disease control rate deserve further attention for this convenient, outpatient-based chemotherapy regimen.

Strategies for the management of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) generally develops as a consequence of underlying liver disease, most commonly viral hepatitis. The development of HCC follows an orderly progression from cirrhosis to dysplastic nodules to early cancer development, which can be reliably cured if discovered before the development of vascular invasion (typically occurring at a tumor diameter of approximately 2 cm). The identifiable population at risk makes screening a realistic possibility, and liver imaging is recommended every 6 months for patients with cirrhosis. For patients with preserved liver function and no portal hypertension who develop HCC that is confined to one region of the liver, resection is the preferred treatment. If resection is not possible because of poor liver function, and the HCC is within the Milan criteria (1 nodule > or =5 cm, 2-3 nodules > or =3 cm), liver transplantation is the treatment of choice. To prevent tumor progression while waiting, nonsurgical treatments including percutaneous ethanol injection, radiofrequency ablation, and transarterial chemoembolization are employed, but drop-out from the waiting list remains a problem. Living donor transplantation is an alternative that can eliminate drop-out and enable liver transplantation for patients with HCC whose disease does not fall within the Milan criteria. There is a need for more effective adjuvant therapies after resection and liver transplantation; newer antiangiogenic agents offer hope for improved outcomes in the future.

Oncolytic HSV and erlotinib inhibit tumor growth and angiogenesis in a novel malignant peripheral nerve sheath tumor xenograft model

Malignant peripheral nerve sheath tumors (MPNSTs), driven in part by hyperactive Ras and epidermal growth factor receptor (EGFR) signaling, are often incurable. Testing of therapeutics for MPNST has been hampered by lack of adequate xenograft models. We previously documented that human MPNST cells are permissive for lytic infection by oncolytic herpes simplex viruses (oHSV). Herein we developed and characterized a xenograft model of human MPNST and evaluated the antitumor effects of oHSV mutants (G207 and hrR3) and the EGFR inhibitor, erlotinib. Additive cytotoxicity of these agents was found in human MPNST cell lines, suggesting that EGFR signaling is not critical for virus replication. Mice bearing human MPNST tumors treated with G207 or hrR3 by intraperitoneal or intratumoral injection showed tumor-selective virus biodistribution, virus replication, and reduced tumor burden. oHSV injection demonstrated more dramatic antitumor activity than erlotinib. Combination therapies showed a trend toward an increased antiproliferative effect. Both oHSV and erlotinib were antiangiogenic as measured by proangiogenic gene expression, effect on endothelial cells and xenograft vessel density. Overall, oHSVs showed highly potent antitumor effects against MPNST xenografts, an effect not diminished by EGFR inhibition. Our data suggest that inclusion of MPNSTs in clinical trials of oHSV is warranted.

Erlotinib-associated acute pneumonitis: report of two cases

Two cases of erlotinib-associated acute pneumonitis are described. The first patient was started on erlotinib treatment for metastatic non-small cell lung cancer. The second patient was treated with erlotinib for metastatic adenocarcinoma of unknown origin. Both patients developed dyspnea and hypoxemia five to six days after initiation of erlotinib treatment. In both cases, computed tomography scan of the chest showed extensive bilateral ground-glass infiltrates consistent with pneumonitis. In both patients, acute pneumonitis resulted in respiratory failure requiring intubation and mechanical ventilation. Diffuse alveolar hemorrhage was excluded by bronchoscopy in both cases. Bronchoalveolar lavage cultures were negative. Erlotinib treatment was stopped and both patients were treated with corticosteroids. The first patient improved gradually and finally was discharged to a rehabilitation centre, but unfortunately the second patient died of Klebsiella sepsis. Naranjo causality scale in both cases suggested a probable association between erlotinib and pneumonitis. Literature on erlotinib-associated pneumonitis is sparse. The clinical presentation and radiographic findings of erlotinib-associated acute pneumonitis are described.

Hepatocellular carcinoma: molecular biology and therapy

Advanced and metastatic hepatocellular carcinomas (HCC) are challenging to treat, and no cytotoxic agents have impacted survival. The underlying liver cirrhosis that commonly accompanies HCC provides an additional challenge; indeed, functional scoring of cirrhosis and HCC is a critical component of patient evaluation. Currently, the molecular biology and pathogenesis of HCC are being increasingly investigated, which may lead to better understanding of the evolution of the disease, especially differing etiologies and identification of survival genes that may affect outcome. Early studies of targeted therapies in HCC have shown disease stabilization, and an increased understanding of the mechanism(s) of these novel agents combined with correlative studies may lead to the identification of an active agent or combination of agents that impacts the natural history of HCC.

Gemcitabine plus oxaliplatin (GEMOX) in patients with advanced hepatocellular carcinoma (HCC)

BACKGROUND

New systemic therapies are needed to improve the prognosis of patients with advanced-stage hepatocellular carcinoma (HCC). In a Phase II trial involving previously untreated patients with advanced HCC, the more favorable schedule from a previous pilot study was evaluated.

METHODS

Thirty-four patients with previously untreated advanced-stage HCC were prospectively enrolled. The GEMOX regimen consisted of gemcitabine 1000 mg/m(2) on Day 1 and oxaliplatin 100 mg/m(2) on Day 2. The treatment was repeated every 2 weeks until disease progression or limiting toxicity.

RESULTS

Thirty-two patients were assessable for efficacy and 33 for toxicity. In all, 323 treatment cycles were administered. No toxic deaths occurred. Hematological grade 3-4 toxicity consisted of thrombocytopenia (27% of patients) and neutropenia (24%), including 2 febrile neutropenia and anemia (9%). Grade 3 oxaliplatin-induced neurotoxicity was observed in 3 (9%) patients. The overall response rate was 18% (95% confidence interval [CI]: 8-34) and disease stabilization was observed in 58% of patients (including 5 minor responses), giving a disease control rate of 76%. Median progression-free and overall survival times were, respectively, 6.3 months (95% CI: 4.3-10.1 months) and 11.5 months (95% CI: 8.5-14.3 months). Treatment was significantly more effective in patients with nonalcoholic cirrhosis than in those with alcoholic cirrhosis.

CONCLUSIONS

The GEMOX regimen seems to be well tolerated and active in advanced HCC, especially in patients with underlying nonalcoholic liver disease. A Phase II study of the GEMOX regimen plus cetuximab is ongoing.

New molecular targets for hepatocellular carcinoma: the ErbB1 signaling system

Hepatocellular carcinoma (HCC) is a major cause of cancer-related deaths. This malignancy is often diagnosed at an advanced state, when most potentially curative therapies are of limited efficacy. In addition, HCC is a type of tumor highly resistant to available chemotherapeutic agents, which leaves HCC patients with no effective therapeutic options and a poor prognosis. From a molecular perspective, HCC is a heterogeneous type of tumor. However, in most cases, HCC emerges on a background of persistent liver injury, inflammation and hepatocellular proliferation, which is characteristic of chronic hepatitis and cirrhosis. Recent studies have revealed that dysregulation of a limited number of growth and survival-related pathways can play a key role in HCC development. The epidermal growth factor receptor (ErbB1) can be bound and activated by a broad family of ligands, and can also engage in extensive cross talk with other signaling pathways. This system is considered as an important defense mechanism for the liver during acute tissue injury; however, accumulating evidences suggest that its chronic stimulation can participate in the neoplastic conversion of the liver. Agents that target the ErbB1 receptor have shown antineoplastic activity in other types of tumors, but their efficacy either alone or in combination with other compounds has just started to be tested in experimental and human HCC. Here, we review the evidences that support the involvement of the ErbB1 in HCC development and that provide a rationale for ErbB1 targeting in HCC prevention and treatment.

Plasma and Cerebrospinal Fluid Pharmacokinetics of Erlotinib and Its Active Metabolite OSI-420

PURPOSE

To report cerebrospinal fluid (CSF) penetration of erlotinib and its metabolite OSI-420.

EXPERIMENTAL DESIGN

Pharmacokinetic measurements were done in plasma (days 1, 2, 3, and 8 of therapy) and, concurrently, in plasma and CSF (before and at 1, 2, 4, 8, and 24 h after dose on day 34 of therapy) in an 8-year-old patient diagnosed with glioblastoma who received local irradiation and oral erlotinib in a phase I protocol. CSF samples were collected from a ventriculoperitoneal shunt, which was externalized because of infection. Erlotinib concentrations were determined by liquid chromatography/mass spectrometry. CSF penetration of erlotinib and OSI-420 were estimated by a compartmental model and by calculating the ratio of CSF to plasma 24-h area under concentration-time curve (AUC(0-24)).

RESULTS

This patient was assigned to receive erlotinib at a dose level of 70 mg/m(2), but the actual daily dose was 75 mg (78 mg/m(2)). Erlotinib and OSI-420 plasma pharmacokinetic variables on days 8 and 34 overlapped to suggest that steady state had been reached. Whereas erlotinib and OSI-420 AUC(0-24) in plasma on day 34 were 30,365 and 2,527 ng h/mL, respectively, the correspondent AUC(0-24) in the CSF were 2,129 and 240 ng h/mL, respectively. Erlotinib and OSI-420 CSF penetration were 7% and approximately 9%, respectively, using both estimate methods. The maximum steady-state CSF concentration of erlotinib was approximately 130 ng/mL (325 nmol/L).

CONCLUSIONS

The plasma pharmacokinetics of erlotinib in this child overlapped with results described in adults. Oral administration of erlotinib achieves CSF concentrations comparable with those active against several cancer cell lines in preclinical models.

Treatment Approaches for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide, and it is responsible for up to one million deaths annually. Although multiple risk factors for HCC have been identified, and despite preventive measures, the incidence of HCC continues to rise to epidemiologic proportions in the United States. In general, tumor resection and orthotopic liver transplantation are the treatment with the best outcome; however, HCC is generally diagnosed late in its course when patients are not eligible for curative treatment options. HCC is a relatively Chemo-refractory tumor secondary to heterogeneity of the tumor and the high rate of multidrug resistant gene expression. There are no standard treatments for HCC, multiple palliative treatment modalities have been used for patients with unresectable disease. None of these modalities have shown any superiority; and the retrospective nature of these available data has confounded any reasonable conclusions. Different institutions use different treatment schema dependent on the center expertise. Sorafenib, a tyrosine kinase inhibitor, has recently demonstrated a survival advantage in metastatic HCC, and if approved by the FDA, might become the standard of care. In this article we will review the rationale behind the currently available treatment options for HCC.

Systemische Therapie von Leber- und Gallenwegstumoren

Hepatocellular carcinoma (HCC) is generally difficult to treat. This is primarily due to the reduced liver function of most patients and the low sensitivity of liver cancer cells to chemotherapy. This has been demonstrated in many clinical trials. Molecular therapies might represent an improvement in the systemic treatment of patients with HCC. In addition to anti-angiogenic drugs, compounds which interfere with specific signal transduction cascades have shown promising results in smaller trials. There are only limited numbers of studies about the systemic treatment options for biliary cancers. To date, the best response rates have been achieved with combination chemotherapies containing platinum analogues and gemcitabine. In the absence of larger clinical phase III trials, no standard chemotherapy for biliary cancers exists today.

Epidermal Growth Factor Receptor Activation: How Exon 19 and 21 Mutations Changed Our Understanding of the Pathway

The discovery of epidermal growth factor receptor (EGFR) mutations in never-smokers has been the most relevant finding ever in non–small cell lung cancer. When patients whose tumors bear the sensitizing mutations are treated with the tyrosine kinase inhibitors gefitinib or erlotinib, we witness response rates and durations never before reported, including complete responses. At the same time, the presence of EGFR mutations has raised numerous new questions, tantalizing data, and new challenges for treatment. This is particularly true as we try to generalize the findings in lung cancer to other malignancies. The indiscriminate use of gefitinib or erlotinib in the general lung cancer population results in meager survival benefit for patients. Similarly, the tyrosine kinase inhibitors have limited activity in a variety of tumor types with EGFR overexpression. This has led to the question of whether EGFR remains a viable target in patients other than those whose tumors contain mutations, and whether the modest activity of cetuximab in colorectal cancer and head and neck cancer represents all that we can expect from inhibition of this pathway in the absence of mutation. Mechanisms of pathway activation other than mutation have been discovered in recent years, and include overexpression mediated by gene amplification or by amplification of a dinucleotide repeat in the EGFR promoter, mutation of an extracellular region on EGFR generating a mutant protein termed EGFRvIII, and enhanced signaling due to heterodimerization with other members of the EGFR family, particularly overexpression of HER2/HER3. The extent to which these paths to EGFR activation will confer sensitivity to the tyrosine kinase inhibitors or to EGFR monoclonal antibodies is being explored. Thus far, published clinical data suggest that there is little room for the administration of gefitinib or erlotinib in the absence of EGFR mutations. The five articles in this edition of CCR Focus will address the various mechanisms of EGFR pathway activation and provide insight into the potential for translation into clinical relevance.

A novel mutation in the tyrosine kinase domain of ERBB2 in hepatocellular carcinoma

Background

Several studies showed that gain-of-function somatic mutations affecting the catalytic domain of EGFR in non-small cell lung carcinomas were associated with response to gefitinib and erlotinib, both EGFR-tyrosine kinase inhibitors. In addition, 4% of non-small cell lung carcinomas were shown to have ERBB2 mutations in the kinase domain. In our study, we sought to determine if similar respective gain-of-function EGFR and ERBB2 mutations were present in hepatoma and/or biliary cancers.

Methods

We extracted genomic DNA from 40 hepatoma (18) and biliary cancers (22) samples, and 44 adenocarcinomas of the lung, this latter as a positive control for mutation detection. We subjected those samples to PCR-based semi-automated double stranded nucleotide sequencing targeting exons 18–21 of EGFR and ERBB2. All samples were tested against matched normal DNA.

Results

We found 11% of hepatoma, but no biliary cancers, harbored a novel ERBB2 H878Y mutation in the activating domain.

Conclusion

These newly described mutations may play a role in predicting response to EGFR-targeted therapy in hepatoma and their role should be explored in prospective studies.

Hepatocellular carcinoma: molecular biology and therapy

Advanced and metastatic hepatocellular carcinomas (HCC) are challenging to treat, and no cytotoxic agents have impacted survival. The underlying liver cirrhosis that commonly accompanies HCC provides an additional challenge; indeed, functional scoring of cirrhosis and HCC is a critical component of patient evaluation. Currently, the molecular biology and pathogenesis of HCC are being increasingly investigated, which may lead to better understanding of the evolution of the disease, especially differing etiologies and identification of survival genes that may affect outcome. Early studies of targeted therapies in HCC have shown disease stabilization, and an increased understanding of the mechanism(s) of these novel agents combined with correlative studies may lead to the identification of an active agent or combination of agents that impacts the natural history of HCC.

Small molecule tyrosine kinase inhibitors in the treatment of solid tumors: an update of recent developments

Small molecule tyrosine kinase inhibitors (TKIs) are developed to block intracellular signaling pathways in tumor cells, leading to deregulation of key cell functions such as proliferation and differentiation. Over 25 years ago, tyrosine kinases were found to function as oncogenes in animal carcinogenesis; however, only recently TKIs were introduced as anti cancer drugs in human cancer treatment. Tyrosine kinase inhibitors have numerous good qualities. First, in many tumor types they tend to stabilize tumor progression and may create a chronic disease state which is no longer immediately life threatening. Second, side effects are minimal when compared to conventional chemotherapeutic agents. Third, synergistic effects are seen in vitro when TKIs are combined with radiotherapy and/or conventional chemotherapeutic agents. In this article, we will give an update of the tyrosine kinase inhibitors that are currently registered for use or in an advanced stage of development, and we will discuss the future role of TKIs in the treatment of solid tumors. The following TKIs are reviewed: Imatinib (Gleevec/Glivec), Gefitinib (Iressa), Erlotinib (OSI-774, Tarceva), Lapatinib (GW-572016, Tykerb), Canertinib (CI-1033), Sunitinib (SU 11248, Sutent), Zactima (ZD6474), Vatalanib (PTK787/ZK 222584), Sorafenib (Bay 43-9006, Nexavar), and Leflunomide (SU101, Arava).

Phase II trial of erlotinib in gastroesophageal junction and gastric adenocarcinomas: SWOG 0127

PURPOSE

A phase II trial of the oral epidermal growth factor receptor (EGFR) inhibitor erlotinib in patients with gastroesophageal adenocarcinomas stratified according to primary tumor location into two groups: gastroesophageal junction (GEJ)/cardia and distal gastric adenocarcinomas.

PATIENTS AND METHODS

Patients with a histologically proven diagnosis of adenocarcinoma of the GEJ or stomach (ST) that was unresectable or metastatic; presence of measurable disease; no prior chemotherapy for advanced or metastatic cancer; Zubrod performance status (PS) of 0 to 1; and adequate renal, hepatic, and hematologic function were treated with erlotinib 150 mg/d orally. Patient characteristics were median age, GEJ-63 years, ST-64 years; sex, GEJ-84% male and 16% female, ST-60 male and 40 female; Zubrod PS, GEJ-25 had a PS of 0 and 18 had a PS 1, ST-13 had a PS of 0 and 12 had a PS of 1.

RESULTS

Percentage of common toxicities were skin rash, 86% and 72%; fatigue, 51% and 44%; and AST/ALT elevation, 28% and 28%, respectively for GEJ and ST. There has been one confirmed complete response, three confirmed partial responses (PRs) and one unconfirmed PR for an overall response probability of 9% confirmed (95% CI, 3% to 22%), all occurring in GEJ stratum. No responses were observed in ST stratum. The median survival was 6.7 months in GEJ and 3.5 months in ST stratum. Neither intratumoral EGFR, transforming growth factor-alpha or phosphorylated Akt kinase expression nor plasma proteomic analyses were predictive of clinical outcome. No somatic mutations of the EGFR exons 18, 19, or 21 were detected and there was no gross amplification of EGFR by fluorescence in situ hybridization.

CONCLUSION

Erlotinib is active in patients with GEJ adenocarcinomas, but appears inactive in gastric cancers. The molecular correlates examined were not predictive of the patient therapeutic response.

EGFR is phosphorylated at Ty845 in hepatocellular carcinoma

Epidermal growth factor receptor (EGFR) is overexpressed in a significant proportion of hepatocellular carcinomas. Recent studies of EGFR inhibitors to treat hepatocellular carcinoma have been encouraging and better understanding of EGFR signaling may lead to more effective strategies for inhibiting this key pathway. The EGFR can be phosphorylated at different tyrosine sites, leading to subsequent activation of different pathways. Cell line and animal studies have shown that MAPK and STAT-3 are important mediators of the EGFR signal in liver cells. However, little is known about EGFR phosphorylation and subsequent signaling in primary hepatocellular carcinoma. We investigated the site of EGFR phosphorylation by Western blot in 18 hepatocellular carcinomas. Fourteen of 18 hepatocellular carcinomas had detectable EGFR by Western blotting and 13 of 14 showed phosphorylation at tyrosine 845. In contrast, no EGFR phosphorylation was detected at tyrosine 998, tyrosine 1045, or tyrosine 1068, which signal through other pathways including STAT-3 and MAPK. These findings were further explored by examination of EGFR expression and signaling pathway activation in tissue arrays comprised of 73 hepatocellular carcinomas using antibodies that recognize phosphorylated (or activated) proteins. Tissue array studies also found no correlation between EGFR expression (29% of cases) and STAT-3 nuclear positivity (16%), AKT (4%), MAPK (3%), or STAT-5 (3%) positivity, all P>0.05. EGFR expression was correlated with hepatitis B infection, but not with tumor size, nuclear grade, or proliferative rate. We conclude that EGFR is phosphorylated at tyrosine 845 in most hepatocellular carcinomas and that EGFR expression by immunohistochemistry does not correlate well with STAT-3, STAT-5, MAPK, or AKT immunostaining.

Recurrence after liver resection for hepatocellular carcinoma: risk factors, treatment, and outcomes

BACKGROUND

Tumor recurrence remains the major cause of death after curative resection for hepatocellular carcinoma (HCC). The purpose of this study was to identify risk factors for the recurrence of HCC and to examine long-term outcomes after resection.

METHODS

From July 1992 to July 2004, 193 consecutive patients who underwent hepatic resection as primary therapy with curative intent for HCC were included in this single-center analysis. The perioperative mortality rate was 5%. Time to recurrence (disease-free survival) and overall survival were determined by Kaplan-Meier analysis. Demographic, tumor, and treatment characteristics were tested for their prognostic significance by univariate and multivariate analysis with the log-rank test and the Cox proportional hazards model, respectively.

RESULTS

Median overall survival for the entire cohort was 71 +/- 11 months; disease-free survival was 34 months (range, 1-149 months). After a median follow-up time of 34 months, 98 patients (51%) experienced recurrent cancer; initial tumor recurrence was confined to the liver in 86 patients (88%). With the use of multivariate analysis, preoperative vascular invasion detected on radiologic imaging studies; postoperative vascular invasion found on pathologic assessment, and intermediate and poor tumor differentiation and tumor size and number were significant predictors of disease-free survival. Of the 98 patients who had tumor recurrence, 53 patients (54%) underwent additional therapy (ablation, 31 patients; re-resection, 11 patients; transarterial chemoembolization, 8 patients; liver transplantation, 3 patients) with improvement in survival.

CONCLUSION

Despite recurrences in >50% of patients, long-term survival can be achieved after resection of HCC. Identification of risk factors, close follow-up evaluation, and early detection are mandatory because recurrences that are confined to the liver may be amenable to treatment with an additional survival benefit.

Molecular pathogenesis of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common life-threatening malignancies in the world. This cancer generally arises within the boundaries of well-defined causal factors, of which viral hepatitis infection, aflatoxin exposure, chronic alcohol abuse, and nonalcoholic steatohepatitis are the major risk factors. Despite the identification of these etiological agents, hepatocarcinogenesis remains poorly understood. The molecular mechanisms leading to the development of HCC appear extremely complex and only recently have begun to be elucidated. Currently, surgical resection or liver transplantation offer the best chance of cure for the patient with HCC; however, these therapies are hindered by inability of many of these patients to undergo liver resection, by tumor recurrence and by donor shortages. A lack of suitable therapeutic strategies has led to a greater focus on prevention of HCC using antiviral agents and vaccination. Overall, the current outlook for patients with HCC is bleak; however, a better understanding of the molecular and genetic basis of this cancer should lead to the development of more efficacious therapies.

Suppression of Mcl-1 via RNA interference sensitizes human hepatocellular carcinoma cells towards apoptosis induction

Background

Hepatocelluar carcinoma (HCC) is one of the most common cancers worldwide and a major cause of cancer-related mortality. HCC is highly resistant to currently available chemotherapeutic drugs. Defects in apoptosis signaling contribute to this resistance. Myeloid cell leukemia-1 (Mcl-1) is an anti-apoptotic member of the Bcl-2 protein family which interferes with mitochondrial activation. In a previous study we have shown that Mcl-1 is highly expressed in tissues of human HCC. In this study, we manipulated expression of the Mcl-1 protein in HCC cells by RNA interference and analyzed its impact on apoptosis sensitivity of HCC cells in vitro.

Methods

RNA interference was performed by transfecting siRNA to specifically knock down Mcl-1 expression in HCC cells. Mcl-1 expression was measured by quantitative real-time PCR and Western blot. Induction of apoptosis and caspase activity after treatment with chemotherapeutic drugs and different targeted therapies were measured by flow cytometry and fluorometric analysis, respectively.

Results

Here we demonstrate that Mcl-1 expressing HCC cell lines show low sensitivity towards treatment with a panel of chemotherapeutic drugs. However, treatment with the anthracycline derivative epirubicin resulted in comparatively high apoptosis rates in HCC cells. Inhibition of the kinase PI3K significantly increased apoptosis induction by chemotherapy. RNA interference efficiently downregulated Mcl-1 expression in HCC cells. Mcl-1 downregulation sensitized HCC cells to different chemotherapeutic agents. Sensitization was accompanied by profound activation of caspase-3 and -9. In addition, Mcl-1 downregulation also increased apoptosis rates after treatment with PI3K inhibitors and, to a lower extent, after treatment with mTOR, Raf I and VEGF/PDGF kinase inhibitors. TRAIL-induced apoptosis did not markedly respond to Mcl-1 knockdown. Additionally, knockdown of Mcl-1 efficiently enhanced apoptosis sensitivity towards combined treatment modalities: Mcl-1 knockdown significantly augmented apoptosis sensitivity of HCC cells towards chemotherapy combined with PI3K inhibition.

Conclusion

Our data suggest that specific downregulation of Mcl-1 by RNA interference is a promising approach to sensitize HCC cells towards chemotherapy and molecularly targeted therapies.

Novel concepts in hepatocellular carcinoma: from molecular research to clinical practice

Hepatocellular carcinoma (HCC) is one of the most common malignancies in the world, burdened by a constantly increasing frequency. Therapy is currently restricted to invasive techniques but prognosis and survival are still unsatisfactory, mainly because of HCC recurrence and metastasis diffusion. This review will focus on the problem of tumor recurrence and/or metastasis, pointing out the role of the tissue microenvironment in affecting HCC behavior; new experimental findings will also be discussed in the light of their implications in medical care. Finally, new therapeutic approaches will be considered, paying particular attention to the tissue microenvironment as a potential target. In conclusion, this review will attempt to stimulate debate on translational research into HCC biology, in the field of clinical applications.

Hepatocellular carcinoma pathogenesis: from genes to environment

Hepatocellular carcinoma is among the most lethal and prevalent cancers in the human population. Despite its significance, there is only an elemental understanding of the molecular, cellular and environmental mechanisms that drive disease pathogenesis, and there are only limited therapeutic options, many with negligible clinical benefit. This Review summarizes the current state of knowledge of this, the most common and dreaded liver neoplasm, and highlights the principal challenges and scientific opportunities that are relevant to controlling this accelerating global health crisis.

Signaling pathways involved in the inhibition of epidermal growth factor receptor by erlotinib in hepatocellular cancer

AIM: To examine the underlying mechanisms of erlotinib-induced growth inhibition in hepatocellular carcinoma (HCC).

METHODS: Erlotinib-induced alterations in gene expression were evaluated using cDNA array technology; changes in protein expression and/or protein activation due to erlotinib treatment as well as IGF-1-induced EGFR transactivation were investigated using Western blotting.

RESULTS: Erlotinib treatment inhibited the mitogen activated protein (MAP)-kinase pathway and signal transducer of activation and transcription (STAT)-mediated signaling which led to an altered expression of apoptosis and cell cycle regulating genes as demonstrated by cDNA array technology. Overexpression of proapoptotic factors like caspases and gadds associated with a down-regulation of antiapoptotic factors like Bcl-2, Bcl-X_L or jun D accounted for erlotinib's potency to induce apoptosis. Downregulation of cell cycle regulators promoting the G₁/S-transition and overexpression of cyclin-dependent kinase inhibitors and gadds contributed to the induction of a G₁/G₀-arrest in response to erlotinib. Furthermore, we displayed the transactivation of EGFR-mediated signaling by the IGF-1-receptor and showed erlotinib’s inhibitory effects on the receptor-receptor cross talk.

CONCLUSION: Our study sheds light on the under-standing of the mechanisms of action of EGFR-TK-inhibition in HCC-cells and thus might facilitate the design of combination therapies that act additively or synergistically. Moreover, our data on the pathways responding to erlotinib treatment could be helpful in predicting the responsiveness of tumors to EGFR-TKIs in the future.

New therapies for hepatocellular carcinoma

Hepatocellular carcinoma (HCC), one of the most common cancers worldwide, is often diagnosed at an advanced stage when most potentially curative therapies such as resection, transplantation or percutaneous and transarterial interventions are of limited efficacy. The fact that HCC is resistant to conventional chemotherapy, and is rarely amenable to radiotherapy, leaves this disease with no effective therapeutic options and a very poor prognosis. Therefore, the development of more effective therapeutic tools and strategies is much needed. HCCs are phenotypically and genetically heterogeneous tumors that commonly emerge on a background of chronic liver disease. However, in spite of this heterogeneity recent insights into the biology of HCC suggest that certain signaling pathways and molecular alterations are likely to play essential roles in HCC development by promoting cell growth and survival. The identification of such mechanisms may open new avenues for the prevention and treatment of HCC through the development of targeted therapies. In this review we will describe the new potential therapeutic targets and clinical developments that have emerged from progress in the knowledge of HCC biology, In addition, recent advances in gene therapy and combined cell and gene therapy, together with new radiotherapy techniques and immunotherapy in patients with HCC will be discussed.

Phase II study of erlotinib in patients with advanced biliary cancer

PURPOSE

Epidermal growth factor receptor/human epidermal growth factor receptor 1 and ligand expression is common in biliary cancers (BILI) and may be associated with worse outcome. The primary objective of this study was to determine the proportion of patients with advanced BILI who were progression-free at 6 months.

METHODS

Patients with either unresectable or metastatic disease were studied. Only one prior systemic or locoregional therapy was allowed. Erlotinib was administered continuously at a dose of 150 mg per day orally.

RESULTS

Forty-two patients with BILI were enrolled. The median age was 67 years (range, 33 to 82 years). Fifty-two percent of patients had Eastern Cooperative Oncology Group performance status of 1. Fifty-seven percent of patients had received prior chemotherapy for advanced BILI. HER1/EGFR expression by immunohistochemistry in tumor cells was detected in 29 (81%) of the 36 assessable patients. Seven of the patients (17%; 95% CI, 7% to 31%) were progression free at 6 months. Three patients had partial response by Response Evaluation Criteria in Solid Tumors Group classification of duration 4, 4, and 14 months, respectively. All responding patients had mild (grade 1/2) skin rash and two patients had positive tumoral HER1/EGFR expression. Three patients (7%) had toxicity-related dose reductions of erlotinib due to grade 2/3 skin rash.

CONCLUSION

Results suggest a therapeutic benefit for EGFR blockade with erlotinib in patients with biliary cancer. Additional studies with erlotinib as a single agent and in combination with other targeted agents are warranted in this disease.

Systemic Therapy of Advanced Hepatocellular Carcinoma: How Hopeful Should We Be?

Worldwide, hepatocellular carcinoma (HCC) is the fifth most common cancer and the third most common cause of cancer-related death. In the U.S., 18,510 new cancers of the liver and intrahepatic bile duct are expected in 2006, with an estimated 16,200 deaths. The incidence rates for HCC in the U.S. continued to rise steadily through 1998 and doubled during the period 1975-1995. Unresectable or metastatic HCC carries a poor prognosis, and systemic therapy with cytotoxic agents provides marginal benefit. A majority of HCC patients (>80%) presents with advanced or unresectable disease. Even for those with resected disease, the recurrence rate can be as high as 50% at 2 years. Because of the poor track record of systemic therapy in HCC, there has been a sense of nihilism for this disease in the oncology community for decades. However, with the arrival of newly developed molecularly targeted agents and the success of some of these agents in other traditionally challenging cancers, like renal cell carcinoma, there has recently been renewed interest in developing systemic therapy for HCC. This review attempts to concisely summarize the historical perspective and the current status of systemic therapy development in HCC.

Dysregulation of growth factor signaling in human hepatocellular carcinoma

Dysregulation of pleiotropic growth factors, receptors and their downstream signaling pathway components represent a central protumorigenic principle in human hepatocarcinogenesis. Especially the Insulin-like Growth Factor/IGF-1 receptor (IGF/IGF-1R), Hepatocyte Growth Factor (HGF/MET), Wingless (Wnt/beta-catenin/FZD), Transforming Growth Factor alpha/Epidermal Growth Factor receptor (TGFalpha/EGFR) and Transforming Growth Factor beta (TGFbeta/TbetaR) pathways contribute to proliferation, antiapoptosis and invasive behavior of tumor cells. This review focuses on the relevant alterations in these pathways identified in human human hepatocellular carcinomas (HCCs). Resultant functional effects are modulated by multiple cross-talks between the different signaling pathways and additional tumor-relevant factors, such as cyclooxygenase-2 and p53. Several specific strategies are currently under development such as receptor kinase inhibitors, neutralizing antibodies and antagonistic proteins, which may improve the systemic treatment of human HCCs.

Amphiregulin Contributes to the Transformed Phenotype of Human Hepatocellular Carcinoma Cells

Hepatocellular carcinoma is a major cause of cancer-related deaths. Current treatments are not effective, and the identification of relevant pathways and novel therapeutic targets are much needed. Increasing evidences point to the activation of the epidermal growth factor receptor (EGFR) as an important mechanism in the development of hepatocarcinoma. We previously described that amphiregulin (AR), a ligand of the EGFR, is not expressed in healthy liver but is up-regulated during chronic liver injury, the background on which most liver tumors develop. Now, we have studied the expression and role of AR in human hepatocarcinoma. AR expression and function was studied in human liver tumors and cell lines. AR is expressed in human hepatocellular carcinoma tissues and cell lines and behaves as a mitogenic and antiapoptotic growth factor for hepatocarcinoma cells. We provide several lines of evidence, including AR silencing by small interfering RNAs and inhibition of amphiregulin by neutralizing antibodies, showing the existence of an AR-mediated autocrine loop that contributes to the transformed phenotype. Indeed, interference with endogenous AR production resulted in reduced constitutive EGFR signaling, inhibition of cell proliferation, anchorage-independent growth, and enhanced apoptosis. Moreover, knockdown of AR potentiated transforming growth factor-beta and doxorubicin-induced apoptosis. Conversely, overexpression of AR in SK-Hep1 cells enhanced their proliferation rate, anchorage-independent growth, drug resistance, and in vivo tumorigenic potential. These observations suggest that AR is involved in the acquisition of neoplastic traits in the liver and thus constitutes a novel therapeutic target in human hepatocarcinoma.

Phase II study of gemcitabine and oxaliplatin in combination with bevacizumab in patients with advanced hepatocellular carcinoma

PURPOSE

Hepatocellular carcinoma (HCC) is a vascular tumor with poor prognosis. Given the reported activity of gemcitabine and oxaliplatin (GEMOX) in HCC and the potential benefits of targeting the vascular endothelial growth factor pathway with bevacizumab (B), a phase II study of GEMOX-B was undertaken to define efficacy and toxicity profiles in HCC patients.

PATIENTS AND METHODS

Eligible patients had pathologically proven measurable unresectable or metastatic HCC. For cycle 1 (14 days), bevacizumab 10 mg/kg was administered alone intravenously on day 1. For cycle 2 and beyond (28 days/cycle), bevacizumab 10 mg/kg was administered on days 1 and 15, gemcitabine 1,000 mg/m2 was administered as a dose rate infusion at 10 mg/m2/min followed by oxaliplatin at 85 mg/m2 on days 2 and 16.

RESULTS

Thirty-three patients were enrolled and 30 patients were assessable for efficacy. The objective response rate was 20%, and 27% of patients had stable disease. Median overall survival was 9.6 months (95% CI, 8.0 months to not available) and median progression-free survival (PFS) was 5.3 months (95% CI, 3.7 to 8.7 months); the PFS rate at 3 and 6 months was 70% (95% CI, 54% to 85%) and 48% (95% CI, 31% to 65%), respectively. The most common treatment-related grade 3 to 4 toxicities included leukopenia/neutropenia, transient elevation of aminotransferases, hypertension, and fatigue.

CONCLUSION

GEMOX-B could be safely administered with close monitoring and had moderate antitumor activity for patients with advanced HCC. The high 6-month PFS rate is encouraging, and this regimen is worthy of further investigation.

Expression of tyrosine kinase receptors in malignant midgut carcinoid tumors

BACKGROUND

The expression of certain tyrosine kinase receptors (TKR) has been shown to have a prognostic value in many tumor entities. In recent years, inhibitors and monoclonal antibodies directed towards these receptors have been developed. Several have shown antitumoral effects and have been tested in clinical trials. We wanted to investigate whether midgut carcinoid tumors express TKR and therefore would be suitable for clinical trials with TKR inhibitors (TKRI) or monoclonal antibodies.

MATERIAL AND METHODS

Tumor tissue from 36 patients (24 women and 12 men) with a malignant midgut carcinoid tumor was obtained. The tissues were examined with immunohistochemistry, using polyclonal antibodies against platelet-derived growth factor receptor-alpha (PDGFRalpha), platelet-derived growth factor receptor-beta (PDGFRbeta), epidermal growth factor receptor (EGFR) and c-kit. Human BON1 cells were cultivated and stimulated with PDGF-BB. We also present a case report of a patient with a malignant midgut carcinoid tumor who had stabilization of tumor growth during treatment with imatinib.

RESULTS

Immunohistochemical staining for PDGFRalpha in tumor cells showed immunoreaction for the receptor in 13/34 (38%) for PDGFRbeta in 29/33 (88%), and 24/33 (73%) were immunoreactive for EGFR. No tumor tissue showed immunoreaction for c-kit. In tumor stroma PDGFRalpha was expressed in 35%, PDGFRbeta in 94% and EGFR in 9%. We show that human neuroendocrine tumor cells respond to PDGF, indicating that these tumors express functional PDGF receptors.

CONCLUSION

Malignant midgut carcinoid tumors may express three of the four TKR tested in this investigation. Therefore, these tumors might be susceptible for treatment with TKRI or monoclonal antibodies and this should be further explored in clinical trials.

EGFR blockade by cetuximab alone or as combination therapy for growth control of hepatocellular cancer

Hepatocellular carcinoma (HCC) is one of the most common cancer-related causes of death worldwide. In light of the very poor 5 year survival new therapeutic approaches are mandatory. Several reports indicate that the epidermal growth factor receptor (EGFR) is expressed frequently in HCC, most likely contributing to the aggressive growth characteristics of these tumors. Cetuximab, a chimeric monoclonal IgG1 antibody directed against the EGFR, potently suppresses the growth of various cancers but its effect on HCC remains to be explored. We therefore studied the antineoplastic potency of cetuximab in human HCC cells alone and in combination with growth factor tyrosine-kinase inhibition (TKI) or HMG-CoA-reductase inhibiton or conventional cytostatics. Cetuximab inhibited growth of p53 wild-type HepG2 hepatocellular cancer cells in a time- and dose-dependent manner. Cetuximab treatment resulted in arresting the cell cycle in the G(1)/G(0)-phase due to an increase of expression of the cyclin-dependent kinase inhibitors p21(Waf1/CIP1) and p27(Kip1) and a decrease in cyclin D1 expression. Additionally, we observed a moderate increase in apoptosis as demonstrated by caspase-3 activation. Combining cetuximab with TKIs (erlotinib or AG1024) or the HMG-CoA-reductase inhibitor fluvastatin or doxorubicin resulted in synergistic antiproliferative effects. In contrast, p53 mutated Huh-7 hepatocellular cancer cells proved to be less sensitive towards cetuximab, but when combined with TKIs or fluvastatin or doxorubicin a pronounced reduction of cell growth was observed. To conclude, our study may provide a rationale for future clinical investigations of cetuximab combination therapy for growth control of hepatocellular cancer.