Tivantinib for second-line treatment of advanced hepatocellular carcinoma: a randomised, placebo-controlled phase 2 study

Nanoparticle-formulated siRNA targeting integrins inhibits hepatocellular carcinoma progression in mice

Integrins play an important role during development, regulating cell differentiation, proliferation and survival. Here we show that knockdown of integrin subunits slows down the progression of hepatocellular carcinoma (HCC). Using nanoparticulate delivery of short interfering RNAs targeting β1 and αv integrin subunits we downregulate all integrin receptors in hepatocytes. Short-term integrin knockdown (two weeks) does not cause apparent structural or functional perturbations of normal liver tissue. Alterations in liver morphology accumulate upon sustained integrin downregulation (seven weeks). The integrin knockdown leads to significant retardation of HCC progression, reducing proliferation and increasing tumour cell death. This tumour retardation is accompanied by reduced activation of MET oncogene as well as expression of its mature form on the cell surface. Our data suggest that transformed proliferating cells from HCC are more sensitive to knockdown of integrins than normal quiescent hepatocytes, highlighting the potential of siRNA-mediated inhibition of integrins as an anti-cancer therapeutic approach.

Emerging trends in hepatocellular carcinoma: focus on diagnosis and therapeutics

Hepatocellular carcinoma (HCC) is one of the most common tumors worldwide and one of the deadliest. Patients with chronic liver disease are at the highest risk for developing this tumor. This link provides an opportunity for developing preventive strategies and surveillance that aims at early detection of this tumor and possibly improving outcomes. In this review, we will discuss the latest developments in surveillance strategies, diagnosis, and treatment of this tumor. HCC is the sixth most common cancer in the world, with 782,000 new cases occurring in 2012 worldwide. In 2012, there were 746,000 deaths from liver cancer.1 HCC is the third most fatal cancer in the world.2 The distribution of HCC, which varies geographically, is related to the prevalence of hepatotropic virus. The burden of the disease is the highest in Eastern Asia, sub-Saharan Africa, and Melanesia where hepatitis B (HBV) infection is endemic. Meanwhile, in Japan, United States, and Europe, hepatitis C (HCV) infection is prevalent, and subsequently, is the major risk factor for acquiring HCC in these regions.1,3 It is estimated that the incidence of HCC in Europe and United States will peak at 2020-there will be 78,000 new HCC cases in Europe and 27,000 in the United States-and decline thereafter.1 Indeed, in Japan, the incidence of HCC had already plateaued and started to slowly fall.4 Cirrhosis is the most important risk factor for HCC regardless of etiology and may be caused by chronic viral hepatitis (mainly HBV and HCV), alcoholic liver disease, autoimmune disease, Stage 4 primary biliary cirrhosis, and metabolic diseases such as hereditary hemochromatosis, alpha-1 antitrypsin deficiency, and non-alcoholic fatty liver disease. In the Western hemisphere, HCC occurs in a background of cirrhosis in 90% of the cases.5 Before concentrating on diagnosis and therapeutics, it is important to discuss surveillance for this tumor.

Decoding hepatocellular carcinoma: the promise of microRNAs

MicroRNAs (miRNAs) may play an important role in the development and progression of hepatocellular carcinoma (HCC). Understanding the mechanism of specific miRNAs may provide opportunity for development of biomarkers and novel therapeutics in hepatocellular carcinoma which are desperately needed.

Advances in managing hepatocellular carcinoma

Multiple modalities for treatment of hepatocellular carcinoma are available, depending on tumor size and number. Surgical resection remains the gold standard, so long as the residual liver function reserve is sufficient. In patients with advanced cirrhosis, liver transplantation is the preferred option, as these patients may not have adequate hepatic reserve after resection. Salvage liver transplantation has also become an option for a select few patients who recur after surgical resection. Ablative techniques have been used for palliation as well as to either completely destroy the tumor, act as an adjunct to resection, or downstage the tumor to meet Milan criteria such that a patient may be a candidate for liver transplantation. Radiofrequency ablation, microwave ablation, chemoembolization, radioembolization, and irreversible electroporation have all been used in this capacity. Currently, sorafenib is the only US Food and Drug Administration-approved chemotherapeutic for hepatocellular carcinoma. The efficacy of sorafenib, in combination with other agents, transarterial chemoembolization, and surgical resection is currently being investigated. Sunitinib and brivanib, tyrosine kinase inhibitors, have failed as potential first- or second-line options for chemotherapy. Bevacizumab in combination with erlotinib is also currently being studied. Final analysis for ramucirumab and axitinib are pending. Tivantinib, a selective mesenchymal-epithelial transition factor (MET) inhibitor, is also undergoing clinical trials for efficacy in MET-high tumors. This review serves to emphasize the current and new technologies emerging in the treatment of hepatocellular carcinoma.

Systemic therapies in hepatocellular carcinoma: present and future

Hepatocellular carcinoma (HCC) is now the third leading cause of cancer deathsworldwide and is generally presented at an advanced stage, limiting patients' quality of life. The conventional cytotoxic systemic therapy has proved to be ineffective in HCC, since its induction several decades ago. Today it is possible to use our knowledge of molecular hepatocarcinogenesis to provide a targeted therapy. Sorafenib has demonstrated large improvements in overall survival in HCC. This review describes the molecular mechanisms and potential therapeutic targets, focusing on sorafenib, sunitinib, tivantinib, antiangiogenic agents, and current and future immunotherapies. Thus, it will be necessary in the future to classify HCCs into subgroups according to their genomic and proteomic profiling. The identification of key molecules/receptors/signaling pathways and the assessment of their relevance as potential targets will be the main future challenge potentially influencing response to therapy. Defining molecular targeted agents that are effective for a specific HCC subgroup will hopefully lead to personalized therapy.

Drug therapy for advanced-stage liver cancer

Liver cancer was traditionally treated by surgery or interventional ablative treatments, or, if these options were not feasible, by best supportive care. Since 2008, systemic therapy with the multikinase inhibitor sorafenib has become available worldwide and has become the standard of care for unresectable/non-ablatable or advanced-stage hepatocellular carcinoma (HCC). Sorafenib is able to improve the median overall survival by approximately 3 months. Despite this significant advance in the non-surgical/non-interventional management of liver cancer, this improvement in overall survival is only a first step toward more potent, more targeted, and better tolerated oral antitumor treatments. Since the introduction of sorafenib into clinical practice, several attempts have been made to develop even more effective first-line treatments as well as an effective second-line treatment for HCC. None of these endeavors has been successful so far. The development of drug treatments for HCC has been particularly hampered by the unfortunate push to establish the diagnosis of liver cancer by non-invasive imaging alone, without requiring a liver biopsy for histologic confirmation: this precluded the very necessary search for informative biomarkers and the search for molecular targets for drug development in HCC. This important drawback is being increasingly recognized and corrected. Despite several obstacles remaining to be overcome, it seems reasonable to assume that using a rational, data-driven approach, we will be able to develop better drug treatments for liver cancer in the coming years.

Latin American Association for the Study of the Liver (LAASL) clinical practice guidelines: management of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer in the world and the third most common cause of cancer death, and accounts for 5.6% of all cancers. Nearly 82% of the approximately 550,000 liver cancer deaths each year occur in Asia. In some regions, cancer-related death from HCC is second only to lung cancer. The incidence and mortality of HCC are increasing in America countries as a result of an ageing cohort infected with chronic hepatitis C, and are expected to continue to rise as a consequence of the obesity epidemic. Clinical care and survival for patients with HCC has advanced considerably during the last two decades, thanks to improvements in patient stratification, an enhanced understanding of the pathophysiology of the disease, and because of developments in diagnostic procedures and the introduction of novel therapies and strategies in prevention. Nevertheless, HCC remains the third most common cause of cancer-related deaths worldwide. These LAASL recommendations on treatment of hepatocellular carcinoma are intended to assist physicians and other healthcare providers, as well as patients and other interested individuals, in the clinical decision-making process by describing the optimal management of patients with liver cancer.

Hepatocellular Cancer: New Kids on the Block

BACKGROUND

With over 600,000 newly diagnosed hepatocellular cancer (HCC) patients worldwide every year and ongoing clinical research, it is surprising that many of the new molecular entities have not yet resulted in significant prolongation of progression-free or overall survival. Nevertheless, there are a number of promising agents currently under investigation. Given the unique tumor biology and heterogeneous clinical manifestations of HCC, the application of molecular and cellular markers could also benefit patient selection, disease prognosis and trial design.

SUMMARY

This paper provides an overview of the current therapeutic strategies for HCC in the curative and palliative settings. Furthermore, we introduce some of the promising small molecules and antibodies that may find their way into clinical practice, with a focus on substances that are currently in phase III testing. Finally, we summarize the role of promising biomarkers, such as circulating tumor or cancer stem cells.

KEY MESSAGE

Despite the rising prevalence of HCC and active clinical research, few therapeutic options besides sorafenib have been established. This review discusses the new therapeutic agents in the pipeline.

PRACTICAL IMPLICATIONS

Although many promising preclinical studies have resulted in phase I-II trials on HCC, so far only the tyrosine and Raf kinase inhibitor sorafenib has made its way into the hands of physicians. This multikinase inhibitor is the only approved option for systemic treatment of advanced HCC. Currently, the development of promising approaches for disease management is guided by biomarkers such as molecular markers or cellular characteristics. The use of biomarkers may facilitate early diagnosis in high-risk groups and therefore enhance outcomes by detecting patients whose disease is still curable.

Hepatocellular carcinoma: clinical frontiers and perspectives

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death and is currently the main event leading to death in patients with cirrhosis. Evolving information suggests that the metabolic syndrome with non-alcoholic liver disease may be an important cause of HCC in addition to viral hepatitis and alcohol-induced liver disease. The molecular pathogenesis is extremely complex and heterogeneous. To date the molecular information has not impacted on treatment decisions. Periodic surveillance imaging of patients with cirrhosis is widely practiced, especially because diagnostic, radiographic criteria for early-stage HCC have been defined (including nodules between 1 and 2 cm) and effective treatment is available for tumours detected at an early stage. Worldwide the approach to resection versus transplantation varies depending upon local resources, expertise and donor availability. The criteria for transplantation are discussed, and the controversial areas highlighted with evidence-based recommendations provided. Several approaches are available for intermediate stage disease, including radiofrequency ablation, transarterial chemoembolisation and radioembolisation; the rationale for these therapies is buttressed by appropriate outcome-based studies. For advanced disease, systemic therapy with sorafenib remains the option best supported by current data. Thus, while several trials have failed to improve the benefits of established therapies, studies assessing the sequential or combined application of those already known to be beneficial are needed. Also, new concepts are provided in regards to selecting and stratifying patients for second-line studies, which may help explain the failure of prior studies.

Upregulation of HIF-2α induced by sorafenib contributes to the resistance by activating the TGF-α/EGFR pathway in hepatocellular carcinoma cells

Sorafenib, the first-line systemic drug for advanced hepatocellular carcinoma (HCC), has demonstrated limited benefits with very low response rates. Thus it is essential to investigate the underlying mechanisms for the resistance to sorafenib and seek potential strategy to enhance its efficacy. Hypoxic cells inside solid tumors are extremely resistant to therapies as their survival ability is increased due to the cellular adaptive response to hypoxia, which is controlled by hypoxia-inducible factor (HIF)-1 and HIF-2. Sorafenib inhibits HIF-1α synthesis, making the hypoxic response switch from HIF-1α- to HIF-2α-dependent pathways and providing a mechanism for more aggressive growth of tumors. The present study has demonstrated that upregulation of HIF-2α induced by sorafenib contributes to the resistance of hypoxic HCC cells by activating the transforming growth factor (TGF)-α/epidermal growth factor receptor (EGFR) pathway. Blocking the TGF-α/EGFR pathway by gefitinib, a specific EGFR inhibitor, reduced the activation of STAT (signal transducer and activator of transcription) 3, AKT and ERK (extracellular signal-regulated kinase), and synergized with sorafenib to inhibit proliferation and induce apoptosis of hypoxic HCC cells. Transfection of HIF-2α siRNA into HCC cells downregulated the expression of VEGF (vascular endothelial growth factor), cyclin D1, HIF-2α and TGF-α, and inhibited the activation of EGFR. HIF-2α siRNA inhibited the proliferation and promoted the apoptosis of HCC cells in vitro, and synergized with sorafenib to suppress the growth of HCC tumors in vivo. The results indicate that targeting HIF-2α-mediated activation of the TGF-α/EGFR pathway warrants further investigation as a potential strategy to enhance the efficacy of sorafenib for treating HCC.

Chemotherapy for advanced hepatocellular carcinoma in the sorafenib age

The kinase inhibitor sorafenib is the only systemic therapy proven to have a positive effect on survival of patients with advanced hepatocellular carcinoma (HCC). After development of sorafenib and its introduction as a therapeutic agent used in the clinic, several critical questions have been raised. Clinical parameters and biomarkers predicting sorafenib efficacy are the most important issues that need to be elucidated. Although it is difficult to know the responders in advance using conventional characteristics of patients, there are specific serum cytokines and/or gene amplification in tumor tissues that have been reported to predict efficacy of sorafenib. Risk and benefits of continuation of sorafenib beyond radiological progression is another issue to consider because no other standard therapy for advanced HCC as yet exists. In addition, effectiveness of the expanded application of sorafenib is still controversial, although a few studies have shed some light on combinational treatment with sorafenib for intermediate-stage HCC. Recently, over 50 relevant drugs have been developed and are currently under investigation. The efficacy of some of these drugs has been extensively examined, but none have demonstrated any superiority over sorafenib, so far. However, there are several drugs that have shown efficacy for treatment after sorafenib failure, and these are proceeding to further studies. To address these issues and questions, we have done extensive literature review and summarize the most current status of therapeutic application of sorafenib.

Hepatocellular carcinoma review: current treatment, and evidence-based medicine

Hepatocellular carcinoma (HCC) is the fifth most common tumor worldwide. Multiple treatment options are available for HCC including curative resection, liver transplantation, radiofrequency ablation, trans-arterial chemoembolization, radioembolization and systemic targeted agent like sorafenib. The treatment of HCC depends on the tumor stage, patient performance status and liver function reserve and requires a multidisciplinary approach. In the past few years with significant advances in surgical treatments and locoregional therapies, the short-term survival of HCC has improved but the recurrent disease remains a big problem. The pathogenesis of HCC is a multistep and complex process, wherein angiogenesis plays an important role. For patients with advanced disease, sorafenib is the only approved therapy, but novel systemic molecular targeted agents and their combinations are emerging. This article provides an overview of treatment of early and advanced stage HCC based on our extensive review of relevant literature.

Cabozantinib suppresses tumor growth and metastasis in hepatocellular carcinoma by a dual blockade of VEGFR2 and MET

PURPOSE

MET signaling has been suggested a potential role in hepatocellular carcinoma (HCC) and associated with prometastasis during antiangiogenesis therapy. We investigated the potential association between MET expression and therapeutic response to sorafenib in patients with HCC. Antitumor effects of cabozantinib, a dual inhibitor of MET and VEGFR2, were examined in cultured HCC cells as well as in vivo models.

EXPERIMENTAL DESIGN

Total MET and phosphorylated MET (p-MET) were measured in 29 resected HCC specimens, and correlated with response to sorafenib as postoperative adjuvant therapy. In the second set of experiments using cultured HCC cells, and mouse xenograft and metastatic models, effects of cabozantinib were examined.

RESULTS

High level of p-MET in resected HCC specimens was associated with resistance to adjuvant sorafenib therapy. In cultured HCC cells that expressed p-MET, cabozantinib inhibited the activity of MET and its downstream effectors, leading to G1-phase arrest. Cabozantinib inhibited tumor growth in p-MET-positive and p-MET-negative HCC by decreasing angiogenesis, inhibiting proliferation, and promoting apoptosis, but it exhibited more profound efficacy in p-MET-positive HCC xenografts. Cabozantinib blocked the hepatocyte growth factor (HGF)-stimulated MET pathway and inhibited the migration and invasion of the HCC cells. Notably, cabozantinib reduced the number of metastatic lesions in the lung and liver in the experimental metastatic mouse model.

CONCLUSIONS

Patients with HCC with high level of p-MET are associated with resistance to adjuvant sorafenib treatment. The dual blockade of VEGFR2 and MET by cabozantinib has significant antitumor activities in HCC, and the activation of MET in HCC may be a promising efficacy-predicting biomarker. Clin Cancer Res; 20(11); 2959-70. ©2014 AACR.

Sorafenib for the treatment of hepatocellular carcinoma

The multikinase inhibitor sorafenib, which inhibits targets related to tumor cell proliferation and angiogenesis, was the first systemic agent to demonstrate a significant improvement in the overall survival for patients with advanced hepatocellular carcinoma (HCC) in two large randomized controlled Phase III trials. Together with its manageable safety profile (mainly diarrhea, hand-foot skin reaction and fatigue), sorafenib was approved for the treatment of patients with (unresectable) HCC in 2007. Since then, sorafenib has been established as the standard of care in Child-Pugh A patients with advanced HCC or in those ineligible for or after failure of locoregional therapies in the intermediate stage of the disease. This article summarizes current knowledge and future perspectives regarding the use of sorafenib in patients with HCC.

Tivantinib in MET-high hepatocellular carcinoma patients and the ongoing Phase III clinical trial

There is no available effective systemic treatment for patients with advanced hepatocellular carcinoma (HCC) who are intolerant of sorafenib or who have disease that has progressed on sorafenib. In Phase I and II studies, tivantinib (ARQ 197), an oral inhibitor of MET, demonstrated promising antitumor activity in patients with HCC, both as monotherapy and in combination with sorafenib. A randomized Phase II trial in second-line HCC showed improved overall survival (hazard ratio: 0.38; p = 0.01) in patients with MET-high tumors, as demonstrated by immunohistochemistry, treated with tivantinib versus placebo. Here we present the treatment rationale and study design of the METIV-HCC Phase III study. This randomized, double-blind study will investigate tivantinib monotherapy as second-line treatment in patients with advanced, pretreated, MET-high HCC. Approximately 303 patients will be randomized 2:1 to tivantinib or placebo for the purpose of analyzing the primary end point. Tivantinib will be dosed at 120 mg twice daily, and treatment will continue until disease progression, unacceptable toxicity, patient or physician decision to discontinue, or death. The primary end point of this study is overall survival, while secondary end points include progression-free survival and safety. All patients will be tested for biomarkers. If the primary objective is achieved, this study will provide the first effective therapy for a biologically selected patient population in HCC.

Development of systemic therapy for hepatocellular carcinoma at 2013: updates and insights

A growing number of multi-targeted tyrosine kinase inhibitor (TKI) has undergone testing for hepatocellular carcinoma (HCC). Unfortunately, this enthusiasm has recently been discouraged by a number of negative phase III studies on several anti-angiogenic TKIs in HCC. Several postulations have been made to account for this phenomenon, namely the plateau effects of anti-angiogenesis approach, the heterogeneity of HCC in terms of background hepatitis/cirrhosis and tumor biology, as well as the way how clinical trials are designed. Regardless of the underlying reasons, these results suggested that alternative strategies are necessary to further develop systemic therapy for HCC. Several new strategies are currently evaluated: for examples, molecular agents with activities against targets other than vascular endothelial growth factor receptor are being evaluated in on-going clinical trials. In addition, different approaches of targeted agents in combination with various treatment modalities, such as concurrently with another molecular agent, cytotoxic chemotherapy or transarterial chemoembolization, are being developed. This review aims to give a summary on the results of recently released clinical trials on TKIs, followed by discussion on some of the potential novel agents and combinational approaches. Future directions for testing innovative systemic agents for HCC will also be discussed.

Systemic therapy of hepatocellular carcinoma: Current status and future perspectives

The management of hepatocellular carcinoma (HCC) has substantially changed in the past few decades, the introduction of novel therapies (such as sorafenib) have improved patient survival. Nevertheless, HCC remains the third most common cause of cancer-related deaths worldwide. Decision-making largely relies on evidence-based criteria, as showed in the US and European clinical practice guidelines, which endorse five therapeutic recommendations:resection; transplantation; radiofrequency ablation; chemoembolization; and sorafenib. Many molecularly targeted agents that inhibit angiogenesis, epidermal growth factor receptor, and mammalian target of rapamycin are at different stages of clinical development in advanced HCC. Future research should continue to unravel the mechanism of hepatocarcinogenesis and to identify key relevant molecular targets for therapeutic intervention. Identification and validation of potential surrogate and predictive biomarkers hold promise to individualize patient’s treatment to maximize clinical benefit and minimize the toxicity and cost of targeted agents.

[New drugs in oncology]

BACKGROUND

Drug development in oncology has seen major innovations in recent years. Based on the molecular changes found in malignant tumors, new drugs are being developed which specifically target these altered signaling pathways.

RESULTS

In addition to the already broadly used inhibitors of growth factor and angiogenic signaling pathways, new and innovative target structures have been identified. Cancer stem cells which are thought to be the reason for drug resistance and tumor recurrence are now being targeted. c-MET signaling has emerged as an important new signaling module which can be influenced pharmacologically. Inhibitors of immune checkpoints like antibodies which target the CTLA4 molecule are leading to impressive results in clinical trials. Drugs which influence the epigenetic changes found in tumor cells are tested specifically for their ability to overcome drug resistance. Finally, treatment with oncolytic viruses has made a comeback in certain tumor entities.

CONCLUSION

Oncological treatments will see a significant addition of new drugs and treatment options in the next few years which will hopefully improve the survival of patients with tumors.

The changing landscape of hepatocellular carcinoma: etiology, genetics, and therapy

Hepatocellular carcinoma (HCC) represents one of the leading causes of cancer death and has proved to be highly refractory to treatment. Extensive analysis of the disease has demonstrated that it arises predominantly in response to high-risk etiological challenges, most notably hepatitis virus. However, with evolving vaccination and the obesity epidemic, progressively more cases are associated with underlying metabolic dysfunction. Pathologically diverse forms of HCC are observed, and recent sequencing analysis has defined common events that target well-known cancer pathways including β-catenin/Axin, TP53, and RB/CDKN2A, as well as frequent aberrations in chromatin remodeling factors. However, there are a myriad of low frequency genetic events that make each HCC case unique. Gene expression profiling approaches have successfully been deployed for prognostic assessment of hepatocellular carcinoma and to detect the earliest stages of disease. Despite more extensive research, systemic treatment for HCC is exceedingly limited, with only a handful of drugs providing benefit. Ongoing clinical trials are attempting to exploit specific biological dependencies of HCC to improve the dismal prognosis. Overall, the future of HCC treatment will rely on an understanding of the interplay between etiological factors, molecular features of disease, and rational therapeutic intervention.

Effect of treatment with branched-chain amino acids during sorafenib therapy for unresectable hepatocellular carcinoma

AIM

To examine the effect of branched-chain amino acid (BCAA) therapy for patients with unresectable hepatocellular carcinoma (HCC) treated with sorafenib.

METHODS

Seventy-eight subjects with unresectable HCC with a serum level of albumin of 3.5 g/dL or less treated with sorafenib were evaluated. They were classified into two groups: those receiving BCAA granules (n = 34; BCAA group) or a regular diet (n = 44; control group). We compared overall survival and administration period of sorafenib, and analyzed absolute changes in serum levels of albumin during sorafenib therapy in 41 patients who continued sorafenib therapy for 1 month or more with a follow up of more than 3 months.

RESULTS

Median survival time (MST) in BCAA and control groups was 350 and 143 days (P = 0.007), respectively. Median administration period of sorafenib in the two groups was 59 and 41 days (P = 0.018). In the 41 patients described above, at 1 month, there was no significant change in the serum level of albumin between the two groups, but at 3 months, the difference in the absolute change in the serum level of albumin in the two groups reached significance (P = 0.023). In these subgroup analyses, the administration period of sorafenib as well as the MST in the BCAA group were significantly longer than those in the control group (P = 0.020 and = 0.004).

CONCLUSION

BCAA treatment during sorafenib therapy in HCC patients is useful for maintaining hepatic functional reserve, which may help to avoid early discontinuance of sorafenib therapy and improve survival.

GSK3 alpha and beta are new functionally relevant targets of tivantinib in lung cancer cells

Tivantinib has been described as a potent and highly selective inhibitor of the receptor tyrosine kinase c-MET and is currently in advanced clinical development for several cancers including non-small cell lung cancer (NSCLC). However, recent studies suggest that tivantinib's anticancer properties are unrelated to c-MET inhibition. Consistently, in determining tivantinib's activity profile in a broad panel of NSCLC cell lines, we found that, in contrast to several more potent c-MET inhibitors, tivantinib reduces cell viability across most of these cell lines. Applying an unbiased, mass-spectrometry-based, chemical proteomics approach, we identified glycogen synthase kinase 3 (GSK3) alpha and beta as novel tivantinib targets. Subsequent validation showed that tivantinib displayed higher potency for GSK3α than for GSK3β and that pharmacological inhibition or simultaneous siRNA-mediated loss of GSK3α and GSK3β caused apoptosis. In summary, GSK3α and GSK3β are new kinase targets of tivantinib that play an important role in its cellular mechanism-of-action in NSCLC.

Prognosis of patients with advanced hepatocellular carcinoma who failed first-line systemic therapy

BACKGROUND & AIMS

No approved therapy is available for patients with advanced hepatocellular carcinoma (HCC) who fail first-line therapy. The prognosis of these patients, especially those eligible for clinical trials of second-line therapy, is unclear.

METHODS

All patients who participated in clinical trials of first-line systemic therapy for metastatic or locally advanced HCC in a referral center of Taiwan between 2005 and 2011 were included. Their clinicopathologic characteristics, when the first-line treatment failed, were analyzed and correlated with the overall survival (OS) from the date of first-line treatment failure.

RESULTS

A total of 192 patients were included. Before the start of the first-line therapy, all patients had Child-Pugh class A liver reserves and Cancer of the Liver Italian Program (CLIP) scores ≤4. After the failure of the first-line therapy, the median OS of the entire group was 4.0 months. Patients with Child-Pugh class A liver reserves, when the first-line treatment failed, had significantly better OS than patients with Child-Pugh class B or C liver reserves (median, A vs. B vs. C=7.5 vs. 1.3 vs. 1.0 month, p<0.001). According to the key eligibility criteria of 3 published clinical trials for second-line therapy, 41%-56% of patients were potentially eligible. Compared to patients who were ineligible for clinical trials, potentially eligible patients had longer OS with a median of 7.8-8.6 months.

CONCLUSIONS

Patients with advanced HCC who failed first-line therapy could have substantially improved prognosis if they had Child-Pugh A liver reserves or were potentially eligible for clinical trials.

Met as a therapeutic target in HCC: facts and hopes

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death worldwide, and its burden is expected to increase further in the next years. In spite of the advances of classical therapies, such as surgery, transplantation, use of radiofrequency and transarterial embolization, the prognosis of this neoplasm has not considerably improved over the past few years. The advent of targeted therapies and the approval of the systemic treatment of advanced HCC with the kinase inhibitor sorafenib have provided some hope for the future. Even if the molecular mechanisms responsible for the onset and progression of HCC are still largely unknown, new therapeutic targets have recently come to the spotlight. One of these targets is the tyrosine kinase receptor for the Hepatocyte Growth Factor, encoded by the MET gene, known to promote tumor growth and metastasis in many human organs. In this review we will summarize the contrasting results obtained in vitro (in HCC cell lines) and in animal experimental models and we will also try to analyze the reasons for the opposite findings, suggesting that the HGF/MET axis can have either a promoting or a suppressive role in the development of HCC. We will also reconsider the evidence of activation of this pathway in human HCCs and discuss the results of the clinical trials performed with MET inhibitors. The final purpose is to better clarify which can be the role of MET as a therapeutic target in HCC.

S0941: a phase 2 SWOG study of sorafenib and erlotinib in patients with advanced gallbladder carcinoma or cholangiocarcinoma

Background:

Gallbladder cancers and cholangiocarcinomas make up a heterogenous group of tumours with a poor prognosis in advanced stages. On the basis of evidence of dysregulation of the epidermal growth factor receptor, vascular endothelial growth factor and mitogen-activated protein kinase pathways in biliary cancers, we performed a phase 2 trial of sorafenib and erlotinib in patients with advanced biliary cancers.

Methods:

Eligible patients were previously untreated in the advanced setting with adequate hepatic and bone marrow function. Sorafenib and erlotinib were administered continuously at 400 mg BID and 100 mg daily, respectively.

Results:

Thirty-four eligible patients were recruited. The study was terminated after the first stage of accrual owing to failure to meet the predetermined number of patients who were alive and progression free at 4 months. There were two unconfirmed partial responses (6%, 95% CI: 1–20%), with a median progression-free survival of 2 months (95% CI: 2–3), and median overall survival of 6 months (95% CI: 3–8 months). Grade 3 and 4 adverse events included hypertension, AST/ALT increase, bilirubin increase, diarrhoea, hypokalaemia, hypophosphatemia and rash.

Conclusions:

Despite compelling preclinical rationale, the combination of sorafenib and erlotinib does not have promising clinical activity in an unselected population of patients with biliary cancers. Improved patient selection based on tumour biology and molecular markers is critical for future evaluation of targeted therapies in this disease.

A perspective on molecular therapy in cholangiocarcinoma: present status and future directions

Cholangiocarcinoma (CCA) is an orphan cancer with limited understanding of its genetic and genomic pathogenesis. Typically, it is highly treatment-refractory and patient outcome is dismal. Currently, there are no approved therapeutics for CCA and surgical resection remains the only option with curative intent. Clinical trials are currently being performed in a mixed cohort of biliary tract cancers that includes intrahepatic CCA, extrahepatic/perihilar CCA, distal extrahepatic CCA, gallbladder carcinoma and, in rare cases, even pancreatic cancers. Today, clinical trials fail primarily because they are underpowered mixed cohorts and designed without intent to enrich for markers to optimize success for targeted therapy. This review aims to emphasize current clinical attempts for targeted therapy of CCA, as well as highlight promising new candidate pathways revealed by translational genomics.

[MET signalling pathway and its therapeutic implications in gastrointestinal cancers]

The MET receptor tyrosine kinase and its ligand HGF regulates many signalling pathways involved in proliferation and cell motility, invasion and angiogenesis. Deregulation of HGF-MET system by different biological mechanisms may contribute to the tumour development in many types of cancers. Some pharmacological approaches have been developed to inhibit the HGF-MET signalling pathway, using monoclonal antibodies against HGF or MET, or using tyrosine kinase inhibitors of MET receptor. In digestive cancers, several clinical studies have evaluated the safety and efficacy of these targeted therapies, with some promising results but requiring confirmation in phase III trials. Moreover, it appears that MET tumour expression could be a predictive marker of response to these targeted therapies for some gastrointestinal tumours. Thus, somatic alterations in HGF-MET system may represent interesting therapeutic targets and help to select patients who can favourably respond to such targeted treatment.

The Met receptor tyrosine kinase: a key player in oncogenesis and drug resistance

The Met receptor tyrosine kinase (RTK) is an attractive oncology therapeutic target. Met and its ligand, HGF, play a central role in signaling pathways that are exploited during the oncogenic process, including regulation of cell proliferation, invasion, angiogenesis, and cancer stem cell regulation. Elevated Met and HGF as well as numerous Met genetic alterations have been reported in human cancers and correlate with poor outcome. Alterations of pathways that regulate Met, such as the ubiquitin ligase c-Cbl are also likely to activate Met in the oncogenic setting. Moreover, interactive crosstalk between Met and other receptors such as EGFR, HER2 and VEGFR, underlies a key role for Met in resistance to other RTK-targeted therapies. A large body of preclinical and clinical data exists that supports the use of either antibodies or small molecule inhibitors that target Met or HGF as oncology therapeutics. The prognostic potential of Met expression has been suggested from studies in numerous cancers including lung, renal, liver, head and neck, stomach, and breast. Clinical trials using Met inhibitors indicate that the level of Met expression is a determinant of trial outcome, a finding that is actively under investigation in multiple clinical scenarios. Research in Met prognostics and predictors of drug response is now shifting toward more sophisticated methodologies suitable for development as validated and effective biomarkers that can be partnered with therapeutics to improve patient survival.

Efficacy of combination treatment modalities for intermediate and advanced hepatocellular carcinoma: intra-arterial therapies, sorafenib and novel small molecules

Hepatocellular carcinoma (HCC) is a growing epidemic with a high mortality rate and clear need for improved therapies. In patients with Barcelona-Clinic Liver Cancer (BCLC) B and C, treatment with transarterial chemoembolization (TACE) has been the gold standard in therapy as it delays progression; however, recurrence proves common. In the US, transarterial bead embolization (TABE) has uniformly replaced TACE. With this limited armamentarium, there is need for a shift to novel strategies combining different modalities to further improve patient outcomes. Historically, HCC drug discovery concentrated on common features of HCC including its highly vascular nature and dependence on growth factors (GFs). The multikinase inhibitor sorafenib acts on angiogenesis via modulation of vascular endothelial GF expression and was the first step toward systemic targeted therapy against HCC. Sorafenib has provided clinicians with a tool to modestly improve survival by 2-6 months or longer. Despite the progress in survival provided by TACE, TABE and sorafenib independently, rigorous combination clinical trials do not consistently show significant improvement over TACE/TABE monotherapy. Other novel small molecules targeting angiogenesis such as brivanib, linifanib and everolimus have failed or are in development. Anti-HCV treatment became more feasible with the novel direct-acting antiviral agents; with the much higher and more durable treatment responses that they provide, the risk of HCC progression may be reduced. The most effective strategies in developing combination therapies are hampered by the complexities of FDA testing along with intellectual property and economic issues. To achieve significant progress, more basic science studies are necessary to help understand which novel molecules demonstrate the greatest synergy. Individual patient genomic profiling and biomarkers may help guide therapy and improve the clinician's ability to tailor treatment and to know when it could be appropriate to combine systemic therapy with transarterial embolization. Most importantly, partnerships that facilitate testing of novel therapies in intelligently designed trials based on preclinical pharmacokinetics must be established.

Advanced unresectable hepatocellular carcinoma: new biologics as fresh ammunition or clues to disease understanding?

PURPOSE OF REVIEW

Hepatocellular carcinoma (HCC) is a prevalent malignancy associated with a guarded prognosis. At present, sorafenib is the only approved systemic therapy for patients with advanced disease. The effect of sorafenib on overall survival is modest and limited in time by the occurrence of drug resistance.

RECENT FINDINGS

Together with the increasing knowledge of molecular pathways involved in HCC, targeted molecules have been developed and tested in first and second line following sorafenib. These include antiangiogenic drugs, as well as biologicals inhibiting cell proliferation and survival. Recent phase III trials investigated sunitinib, linifanib, brivanib and erlotinib, but none of them were found superior to sorafenib. New findings in mechanisms of drug resistance create opportunities in the treatment of sorafenib-refractory disease, with cMET inhibition as the most promising approach. This article reviews the pathways involved in HCC and their targets as well as potential strategies for drug development in the future.

SUMMARY

Advanced HCC has been the subject of intensive clinical research following the success of sorafenib. Despite many failures, some agents show promising results in phase II trials. Targeting new pathways, using multidrug regimens and tailoring treatment guided by predictive markers should allow new successes.

Antiangiogenic treatment in hepatocellular carcinoma: the balance of efficacy and safety

Hepatocellular carcinoma (HCC) is a severe complication of advanced liver disease with a worldwide incidence of more than 600,000 patients per year. Liver function, clinical performance status, and tumor size are considered in the Barcelona Clinic Liver Cancer (BCLC) system. While curative treatment options are available for early stages, most patients present with intermediate- or advanced-stage HCC, burdened with a poor prognosis, substantially influenced by the degree of liver-function impairment. Hypervascularization is a major characteristic of HCC, and antiangiogenic treatments are the basis of treatment in noncurative stages, including interventional and pharmacological treatments. Currently, the tyrosine-kinase inhibitor sorafenib is still the only approved drug for HCC. Further improvements in survival in patients with intermediate- and advanced-stage HCC may be anticipated by both multimodal approaches, such as combination of interventional and systemic treatments, and new systemic treatment options. Until now, the Phase III development of other tyrosine-kinase inhibitors in patients with advanced HCC has failed due to minor efficacy and/or increased toxicity compared to sorafenib. However, promising Phase II data have been reported with MET inhibitors in this hard-to-treat population. This review gives a critical overview of antiangiogenic drugs and strategies in intermediate- and advanced-stage HCC, with a special focus on safety.

Molecular targeted therapy for hepatocellular carcinoma: current and future

Hepatocellular carcinoma (HCC) is one of the most frequent tumors worldwide. The majority of HCC cases occur in patients with chronic liver disease. Despite regular surveillance to detect small HCC in these patients, HCC is often diagnosed at an advanced stage. Because HCC is highly resistant to conventional systemic therapies, the prognosis for advanced HCC patients remains poor. The introduction of sorafenib as the standard systemic therapy has unveiled a new direction for future research regarding HCC treatment. However, given the limited efficacy of the drug, a need exists to look beyond sorafenib. Many molecular targeted agents that inhibit different pathways involved in hepatocarcinogenesis are under various phases of clinical development, and novel targets are being assessed in HCC. This review aims to summarize the efforts to target molecular components of the signaling pathways that are responsible for the development and progression of HCC and to discuss perspectives on the future direction of research.

Brivanib in Patients With Advanced Hepatocellular Carcinoma Who Were Intolerant to Sorafenib or for Whom Sorafenib Failed: Results From the Randomized Phase III BRISK-PS Study

Purpose

Brivanib is a selective dual inhibitor of vascular endothelial growth factor and fibroblast growth factor receptors implicated in tumorigenesis and angiogenesis in hepatocellular carcinoma (HCC). An unmet medical need persists for patients with HCC whose tumors do not respond to sorafenib or who cannot tolerate it. This multicenter, double-blind, randomized, placebo-controlled trial assessed brivanib in patients with HCC who had been treated with sorafenib.

Patients and Methods

In all, 395 patients with advanced HCC who progressed on/after or were intolerant to sorafenib were randomly assigned (2:1) to receive brivanib 800 mg orally once per day plus best supportive care (BSC) or placebo plus BSC. The primary end point was overall survival (OS). Secondary end points included time to progression (TTP), objective response rate (ORR), and disease control rate based on modified Response Evaluation Criteria in Solid Tumors (mRECIST) and safety.

Results

Median OS was 9.4 months for brivanib and 8.2 months for placebo (hazard ratio [HR], 0.89; 95.8% CI, 0.69 to 1.15; P = .3307). Adjusting treatment effect for baseline prognostic factors yielded an OS HR of 0.81 (95% CI, 0.63 to 1.04; P = .1044). Exploratory analyses showed a median time to progression of 4.2 months for brivanib and 2.7 months for placebo (HR, 0.56; 95% CI, 0.42 to 0.76; P < .001), and an mRECIST ORR of 10% for brivanib and 2% for placebo (odds ratio, 5.72). Study discontinuation due to treatment-related adverse events (AEs) occurred in 61 brivanib patients (23%) and nine placebo patients (7%). The most frequent treatment-related grade 3 to 4 AEs for brivanib included hypertension (17%), fatigue (13%), hyponatremia (11%), and decreased appetite (10%).

Conclusion

In patients with HCC who had been treated with sorafenib, brivanib did not significantly improve OS. The observed benefit in the secondary outcomes of TTP and ORR warrants further investigation.

Systemic therapy for hepatocellular carcinoma (HCC): from bench to bedside

Primary liver cancer is the fifth most common cancer worldwide and the third most common cause of cancer mortality. For patients with early resectable disease, surgical resection or transplantation is considered a potentially curative modality for hepatocellular carcinoma (HCC); on the other hand, for patients with unresectable or metastatic disease, treatment is essentially palliative and prior to the approval of sorafenib, there was no globally approved systemic treatment for patients presenting with unresectable or metastatic HCC. Sorafenib is the only systemic treatment to demonstrate a statistically significant but modest overall survival benefit in a large phase III trial. Thus, novel systemic approaches represent a high unmet medical need in advanced HCC. In this review article, we will try to take a journey through the history of systemic therapeutic options for HCC passing through the current standard options and exploring the potential new systemic options for this disease.

Development of Tivantinib as Treatment for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a rapidly rising cause of liver-related death worldwide. Most patients are diagnosed at an advanced stage of disease, when systemic therapy is the only viable option for treatment. Significant strides have been made in the molecular understanding of HCC development and growth stimulation. The c-Met pathway has been found to be an important pathway in half of all patients with HCC. HCC tumors with high c-Met activation are associated with an aggressive phenotype and poor prognosis. Tivantinib is a MET receptor tyrosine kinase inhibitor with a broad spectrum of anti-tumor effects currently being studied for the treatment of HCC. Phase I and II data are available for tivantinib in the treatment of solid tumors, including HCC. There appears to be an adequate safety profile, with the main side-effect being neutropenia. In HCC patients with elevated c-Met activity, tivantinib results in an improved time to progression of 2.7 months, compared with 1.4 months in placebo-treated patients. Further studies are ongoing, but early data suggest that tivantinib is a therapy that deserves close attention in the coming years for patients with HCC.

The antiangiogenic ceiling in hepatocellular carcinoma: does it exist and has it been reached?

The recommendation of sorafenib as standard of care in advanced hepatocellular carcinoma has lent support to the increased use of antiangiogenic therapies. However, in three phase 3 randomised trials that compared other antiangiogenics with sorafenib, results did not show superiority or non-inferiority of the new therapies. The 10-month median overall survival shown in these studies for patients given sorafenib might be a ceiling for single-agent antiangiogenic therapy. Strategies to increase survival time include combination therapies that pair antiangiogenic treatment with biological therapy or chemotherapy. The combination of sorafenib and erlotinib was not superior to sorafenib alone, which suggests no positive interaction between antiangiogenics and tyrosine kinase inhibitors in the treatment of advanced hepatocellular carcinoma. A combination of sorafenib and doxorubicin is being assessed in a randomised phase 3 trial. Differences in patient outcome with sorafenib because of disease cause and the ethnic origin of patients suggest that sorafenib's multitarget capacity, including RAF kinase inhibition, might be important. MET inhibitors cabozantinib and tivantinib are drugs that might also bypass the so-called antiangiogenic ceiling and have led to selective treatment of patients that overexpress MET with these drugs. Although this intense period of research activity has not yet resulted in significant improvements in survival for patients with advanced hepatocellular carcinoma, we are certainly closer to a customised treatment, which should increase the antiangiogenic survival ceiling.

Rethinking future development of molecular therapies in hepatocellular carcinoma: a bottom-up approach

The high failure rate of phase 3 trials in oncology is forcing the scientific community to rethink drug development strategies and optimize trial design. The current paradigm of systemic therapies is progressively favoring molecular-based patient selection. In hepatocellular carcinoma, four out of the five phase 3 trials that tested molecular therapies in the last 5 years have been negative. None of them included enriched populations using predicted biomarkers of response. Hence, there is an increasing need to provide new targets and refine selection criteria in HCC clinical trials using molecular readouts of tumor biology.

Clinical trials in hepatocellular carcinoma: an update

The success of sorafenib has spurred an explosive increase of clinical trials testing novel molecular targets and other agents in the treatment of hepatocellular carcinoma (HCC). The paradigm of the studies has been characterized by three noticeable changes. First, the molecular targets of interest have expanded from angiogenesis to cancer cell-directed oncogenic signaling pathways for advanced HCC treatment. Agents targeting EGFR, FGFR, PI3K/Akt/mTOR, TGF-β, c-Met, MEK, IGF signaling, and histone deacetylase have been actively explored. Second, the target indication has shifted from advanced stage to early or intermediate stages of disease. The feasibility of combining locoregional therapies and targeted agents, and the use of novel agents after curative treatments are currently under active investigation. Finally, the therapeutic strategy has shifted from monotherapy to combination targeted therapy. We aim to provide a comprehensive overview of newly disclosed and ongoing clinical trials for the treatment of HCC.

Tivantinib: a new promising mesenchymal-epithelial transition factor inhibitor in the treatment of hepatocellular carcinoma

Tivantinib (ARQ 197) is an orally administered, selective small molecule that inhibits mesenchymal-epithelial transition factor (MET) via a novel, ATP-independent binding mechanism. Preclinical studies demonstrated that tivantinib has a broad-spectrum anti-tumor activity, especially in cells expressing high levels of MET. A randomized Phase II study in second-line hepatocellular carcinoma showed statistically significant improvement in time to progression with tivantinib compared to a placebo. Noteworthy, a significant pronounced benefit in time to progression and overall survival was observed in MET-high patients. In addition, MET expression was defined as a negative prognostic factor. The most frequent adverse events were hematologic events. A Phase III study in the MET-high hepatocellular carcinoma is actively recruiting patients. Phase II and III studies in non-small-cell lung cancer and colorectal cancer are ongoing.

Mechanisms of resistance to sorafenib and the corresponding strategies in hepatocellular carcinoma

Sorafenib, the unique drug as first-line treatment for advanced hepatocellular carcinoma (HCC), has opened a window of hope after searching for effective agents to combat HCC for decades. However, the overall outcomes are far from satisfactory. One of the explanations is the genetic heterogeneity of HCC, which has led to identifying predictive biomarkers for primary resistance to sorafenib, and then applying the concept of personalized medicine, or seeking therapeutic strategies such as combining sorafenib with other anticancer agents. Some of the combinations have demonstrated a better effectiveness than sorafenib alone, with good tolerance. The acquired resistance to sorafenib has also drawn attention. As a multikinase inhibitor, sorafenib targets several cellular signaling pathways but simultaneously or sequentially the addiction switches and compensatory pathways are activated. Several mechanisms are involved in the acquired resistance to sorafenib, such as crosstalks involving PI3K/Akt and JAK-STAT pathways, hypoxia-inducible pathways, epithelial-mesenchymal transition, etc. Based on the investigated mechanisms, some other molecular targeted drugs have been applied as second-line treatment for treat HCC after the failure of sorafenib therapy and more are under evaluation in clinical trials. However, the exact mechanisms accounting for sorafenib resistance remains unclear. Further investigation on the crosstalk and relationship of associated pathways will better our understanding of the mechanisms and help to find effective strategies for overcoming sorafenib resistance in HCC.

Molecular determinants of outcome in sorafenib-treated patients with hepatocellular carcinoma

PURPOSE

Preclinical studies show that sorafenib, a multitarget kinase inhibitor, displays anti-proliferative, anti-angiogenic, and pro-apoptotic properties in hepatocellular carcinoma (HCC). However, the determinants of sorafenib sensitivity in vivo remain largely unknown.

METHODS

We assessed the expression of Mcl-1, activated/phosphorylated extracellular signal-regulated kinase (pERK) 1/2, and activated/phosphorylated AKT (pAKT) in pretreatment tumor specimens from 44 patients with advanced HCC who received sorafenib. Furthermore, we assessed MYC and MET gene copy numbers (GCN) by fluorescence in situ hybridization.

RESULTS

Poorer overall survival (OS) times were correlated with pERK expression [hazard ratio (HR) 1.013; 95 % CI 1.003-1.035] and Mcl-1 expression (HR 1.016; 95 % CI 1.002-1.030) in pretreatment tumor samples. Expression levels of pERK and Mcl-1, however, were not correlated with time to tumor progression (TTP). Increased pERK expression was positively associated with higher Cancer of Liver Italian Program scores (P = 0.012) and was prognostic in patients with scores 2-6 but not in those with scores 0-1. pERK expression was significantly less frequent in specimens sourced from previous surgical procedures compared to biopsy samples (9.6 vs. 92.3 %, respectively; P < 0.0001). Analysis of pAKT expression, MET and MYC GCN, did not indicate any prognostic nor predictive values for these biomarkers in terms of survival.

CONCLUSIONS

Expression levels of Mcl-1 and pERK are associated with reduced OS in HCC patients treated with sorafenib and might be useful markers for risk stratification. However, in contrast to previous findings, pERK expression levels, as well as other biomarkers tested, did not affect TTP.