Sunitinib in hepatocellular carcinoma: redefining appropriate dosing, schedule, and activity end points

Response and outcome following toceranib phosphate treatment for stage four anal sac apocrine gland adenocarcinoma in dogs: 15 cases (2013-2017)

OBJECTIVE

To assess response and outcome in dogs with stage 4 anal sac apocrine gland adenocarcinoma (ASAGA) treated with toceranib phosphate as the sole chemotherapeutic agent.

DESIGN

Retrospective case series.

ANIMALS

15 client-owned dogs with stage 4 ASAGA treated with toceranib phosphate between March 2013 and June 2017.

PROCEDURES

Medical records were reviewed, and data collected included signalment, clinical signs, results of physical examinations and diagnostic procedures, treatments, response, follow-up information, and outcomes. Adverse events and response to treatment were assessed according to standard guidelines, and the Kaplan-Meier product limit method was used for analyses of progression-free interval and survival time.

RESULTS

No dogs had a complete or partial response to treatment with toceranib; however, 13 dogs had signs of clinical benefit. No dogs had signs of toxic effects related to toceranib or were withdrawn completely from treatment because of adverse events. Median progression-free interval and median survival time were 354 and 356 days, respectively.

CONCLUSIONS AND CLINICAL RELEVANCE

Results of the present study indicated that dogs with stage 4 ASAGA treated with toceranib had improved outcomes, compared with outcomes previously reported for dogs with ASAGA that had received non-tyrosine kinase inhibitor treatments. Some dogs had improvement in clinical signs, but euthanasia was often performed because of signs of locoregional failure; therefore, toceranib alone may not be an appropriate treatment for dogs with marked clinical signs attributed to ASAGA, particularly when signs suggest limited quality of life. Further study of toceranib in multimodality treatments for dogs with advanced ASAGA is warranted.

Influence of the Tumor Microenvironment on NK Cell Function in Solid Tumors

Natural killer (NK) cells are a population of innate lymphoid cells playing a pivotal role in host immune responses against infection and tumor growth. These cells have a powerful cytotoxic activity orchestrated by an intricate network of inhibitory and activating signals. The importance of NK cells in controlling tumor growth and in mediating a robust anti-metastatic effect has been demonstrated in different experimental mouse cancer models. Consistently, high density of tumor-infiltrating NK cells has been linked with a good prognosis in multiple human solid tumors. However, there are also tumors that appear to be refractory to NK cell-mediated killing for the presence of an immunosuppressive microenvironment affecting NK cell function. Immunotherapeutic strategies aimed at restoring and increasing the cytotoxic activity of NK cells in solid tumors, including the adoptive transfer of NK and CAR-NK cells, are currently employed in preclinical and clinical studies. In this review, we outline recent advances supporting the direct role of NK cells in controlling expansion of solid tumors and their prognostic value in human cancers. We summarize the mechanisms adopted by cancer cells and the tumor microenvironment to affect NK cell function, and finally we evaluate current strategies to augment the antitumor function of NK cells for the treatment of solid tumors.

Clinical Pharmacokinetics and Pharmacodynamics of Transarterial Chemoembolization and Targeted Therapies in Hepatocellular Carcinoma

The management of hepatocellular carcinoma (HCC) is based on a multidisciplinary decision tree. Treatment includes loco-regional therapy, mainly transarterial chemoembolization, for intermediate-stage HCC and systemic therapy with oral tyrosine kinase inhibitors (TKIs) for advanced HCC. Transarterial chemoembolization involves hepatic intra-arterial infusion with either conventional procedure or drug-eluting-beads. The aim of the loco-regional procedure is to deliver treatment as close as possible to the tumor both to embolize the tumor area and to enhance efficacy and minimize systemic toxicity of the anticancer drug. Pharmacokinetic studies applied to transarterial chemoembolization are rare and pharmacodynamic studies even rarer. However, all available studies lead to the same conclusions: use of the transarterial route lowers systemic exposure to the cytotoxic drug and leads to much higher tumor drug concentrations than does a similar dose via the intravenous route. However, reproducibility of the procedure remains a major problem, and no consensus exists regarding the choice of anticancer drug and its dosage. Systemic therapy with TKIs is based on sorafenib and lenvatinib as first-line treatment and regorafenib and cabozantinib as second-line treatment. Clinical use of TKIs is challenging because of their complex pharmacokinetics, with high liver metabolism yielding both active metabolites and their common toxicities. Changes in liver function over time with the progression of HCC adds further complexity to the use of TKIs. The challenges posed by TKIs and the HCC disease process means monitoring of TKIs is required to improve clinical management. To date, only partial data supporting sorafenib monitoring is available. Results from further pharmacokinetic/pharmacodynamic studies of these four TKIs are eagerly awaited and are expected to permit such monitoring and the development of consensus guidelines.

Recent developments of c-Met as a therapeutic target in hepatocellular carcinoma

Aberrant c-Met activity has been implicated in the development of hepatocellular carcinoma (HCC), suggesting that c-Met inhibition may have therapeutic potential. However, clinical trials of nonselective kinase inhibitors with c-Met activity (tivantinib, cabozantinib, foretinib, and golvatinib) in patients with HCC have failed so far to demonstrate significant efficacy. This lack of observed efficacy is likely due to several factors, including trial design, lack of patient selection according to tumor c-Met status, and the prevalent off-target activity of these agents, which may indicate that c-Met inhibition is incomplete. In contrast, selective c-Met inhibitors (tepotinib, capmatinib) can be dosed at a level predicted to achieve complete inhibition of tumor c-Met activity. Moreover, results from early trials can be used to optimize the design of clinical trials of these agents. Preliminary results suggest that selective c-Met inhibitors have antitumor activity in HCC, with acceptable safety and tolerability in patients with Child-Pugh A liver function. Ongoing trials have been designed to assess the efficacy and safety of selective c-Met inhibition compared with standard therapy in patients with HCC that were selected based on tumor c-Met status. Thus, c-Met inhibition continues to be an active area of research in HCC, with well-designed trials in progress to investigate the benefit of selective c-Met inhibitors. (Hepatology 2018;67:1132-1149).

Sunitinib represses regulatory T cells to overcome immunotolerance in a murine model of hepatocellular cancer

Successful development of immunotherapeutic strategies for hepatocellular cancer (HCC) has been impeded by limited understanding of tumor-induced profound tolerance and lack of a clinically faithful HCC model. Recently, we developed a novel model that recapitulates typical features of human HCC. Using this clinically relevant model, we demonstrate that tumor growth impairs host immunity and causes a profound exhaustion of tumor antigen-specific (TAS) CD8⁺ T cells. Increase in frequency and suppressive function of regulatory T cells (Tregs) is critically involved in this tumor-induced immune dysfunction. We further demonstrate that sunitinib suppresses Tregs and prevents tumor-induced immune tolerance, allowing TAS immunization to activate endogenous CD8⁺ T cells. As a result, this combinational strategy delays tumor growth. Importantly, the additional integration of exogenous naïve TAS CD8⁺ T cells by adoptive cell transfer (ACT) leads to the elimination of the established tumors without recurrence and promotes long-term survival of the treated mice. Mechanistically, sunitinib treatment primes the antitumor immune response by significantly decreasing Treg frequency, reducing TGF-β and IL-10 production by Tregs, and also protecting TAS CD8⁺ T cells from tumor-induced deletion in the setting of HCC. Taken together, sunitinib quantitatively and qualitatively modifies Tregs to overcome tumor-induced immune deficiency, suggesting the potential of sunitinib as a therapeutic immune activator for HCC control.

Bioengineered three-dimensional co-culture of cancer cells and endothelial cells: A model system for dual analysis of tumor growth and angiogenesis

Angiogenesis marks the transformation of a benign local tumor into a life-threatening disease. Many in vitro assays are available on two-dimensional (2D) platforms, however, limited research has been conducted to investigate the behavior of tumors and endothelial cells (ECs) grown on three-dimensional (3D) platforms. This study provides a 3D co-culture spheroid of tumor cells with ECs to study the interplay between ECs and tumor cells. In a 3D co-culture with HepG2 hepatocellular carcinoma (HCC) cells, ECs differentiate to form tubule networks when in co-culture. Addition of angiogenic factors or angiogenesis inhibitors to the model system enhanced or inhibited endothelial differentiation in the 3D model, enabling investigations of the cellular signaling pathways utilized in HCC development. The 3D model demonstrated similar protein expression levels as a HCC xenograft, as well as exhibited upregulation of essential signaling proteins such as Akt/mTor in the 3D model, which is not reflected in the 2D model. The effects of several anti-angiogenic agents, such as sorafenib, sunitinib, and axitinib were analyzed in the 3D co-culture model by utilizing fluorescent proteins and a fluorescence resonance energy transfer (FRET)-based caspase-3 sensor in the ECs, which can detect apoptosis in real time. The apoptotic capability of a drug to inhibit angiogenesis in the 3D model can be easily distinguished via the FRET sensor, and dual screening of anti-angiogenesis and anti-tumor drugs can be achieved in a single step via the 3D co-culture model. In summary, a 3D co-culture model is constructed, where a HCC tumor microenvironment with a hypoxic core and true gradient penetration of drugs is achieved for drug screening purposes and in vitro studies utilizing a small HCC tumor. Biotechnol. Bioeng. 2017;114: 1865-1877. © 2017 Wiley Periodicals, Inc.

Safety and Pharmacokinetics of Lenvatinib in Patients with Advanced Hepatocellular Carcinoma

PURPOSE

To determine the maximum tolerable dose (MTD), safety, pharmacokinetics, pharmacodynamics, and preliminary efficacy of lenvatinib in patients with advanced hepatocellular carcinoma (HCC).

EXPERIMENTAL DESIGN

This multicenter, open-label, phase I, dose-escalation study included patients aged 20 to 80 years, refractory to standard therapy, and stratified by hepatic function measured using Child-Pugh (CP) scores: CP-A (score, 5-6) and CP-B (score, 7-8). Lenvatinib was administered continually once daily for 4-week cycles. MTD was defined as the maximum dose associated with ≤ 1 dose-limiting toxicity (DLT) occurring in cycle 1 among 6 patients.

RESULTS

In total, 20 patients (9 in CP-A and 11 in CP-B) were enrolled. The MTD was 12 and 8 mg once daily in CP-A and CP-B, respectively; DLTs included proteinuria, hepatic encephalopathy, and hyperbilirubinemia. The most common grade 3 toxicities included hypertension in CP-A and hyperbilirubinemia in CP-B. Lenvatinib plasma concentration at 24 hours after administration (C24 h) for 12 mg once daily was higher in patients with HCC than in patients with other solid tumors shown in a previous phase I study, but C24 h for 25 mg once daily lenvatinib was comparable. After lenvatinib treatment, the number of circulating endothelial and c-Kit(+) cells decreased and the levels of interleukin (IL)-6, IL10, granulocyte-colony stimulating factor, and vascular endothelial growth factor increased (P < 0.05). Partial responses were observed in 3 patients and tumor shrinkage occurred in 14 patients.

CONCLUSIONS

Lenvatinib (12 mg once daily) demonstrated preliminary efficacy with manageable toxicity and is the recommended dose for phase II studies in patients with HCC and CP-A.

Evaluation of antiangiogenic efficacy in advanced hepatocellular carcinoma: Biomarkers and functional imaging

Many years after therapeutic wilderness, sorafenib finally showed a clinical benefit in patients with advanced hepatocellular carcinoma. After the primary general enthusiasm worldwide, some disappointments emerged particularly since no new treatment could exceed or at least match sorafenib in this setting. Without these new drugs, research focused on optimizing care of patients treated with sorafenib. One challenging research approach deals with identifying prognostic and predictive biomarkers of sorafenib in this population. The task still seems difficult; however appropriate investigations could resolve this dilemma, as observed for some malignancies where other drugs were used.

Disease control with sunitinib in advanced intrahepatic cholangiocarcinoma resistant to gemcitabine-oxaliplatin chemotherapy

Advanced cholangiocarcinoma is associated with poor prognostic survival and has limited therapeutic options available at present. The importance of angiogenesis and expression of pro-angiogenic factors in intrahepatic forms of cholangiocarcinoma suggest that therapies targeting angiogenesis might be useful for the treatment of this disease. Here we report three cases of patients with advanced intrahepatic cholangiocarcinoma progressive after standard chemotherapy and treated with sunitinib 50 mg/d in 6-wk cycles of 4 wk on treatment followed by 2 wk off treatment (Schedule 4/2). In all three patients, sunitinib treatment was associated with a sustained disease control superior to 4 mo, patients achieving either a partial response or stable disease. A reduction in tumor size and density was observed in all cases, suggesting tumor necrosis as a result of sunitinib treatment in these patients. In addition, sunitinib was generally well tolerated and the occurrence of side effects was managed with standard medical interventions, as required. Our results suggest that sunitinib therapy may be associated with favorable outcomes and tolerability in patients with advanced cholangiocarcinoma. Those observations contributed to launch a prospective phase II multicenter trial investigating sunitinib in advanced intrahepatic cholangiocarcinoma (SUN-CK study; NCT01718327).

Vessel caliber--a potential MRI biomarker of tumour response in clinical trials

Our understanding of the importance of blood vessels and angiogenesis in cancer has increased considerably over the past decades, and the assessment of tumour vessel calibre and structure has become increasingly important for in vivo monitoring of therapeutic response. The preferred method for in vivo imaging of most solid cancers is MRI, and the concept of vessel-calibre MRI has evolved since its initial inception in the early 1990s. Almost a quarter of a century later, unlike traditional contrast-enhanced MRI techniques, vessel-calibre MRI remains widely inaccessible to the general clinical community. The narrow availability of the technique is, in part, attributable to limited awareness and a lack of imaging standardization. Thus, the role of vessel-calibre MRI in early phase clinical trials remains to be determined. By contrast, regulatory approvals of antiangiogenic agents that are not directly cytotoxic have created an urgent need for clinical trials incorporating advanced imaging analyses, going beyond traditional assessments of tumour volume. To this end, we review the field of vessel-calibre MRI and summarize the emerging evidence supporting the use of this technique to monitor response to anticancer therapy. We also discuss the potential use of this biomarker assessment in clinical imaging trials and highlight relevant avenues for future research.

Alternative Response Criteria (Choi, European association for the study of the liver, and modified Response Evaluation Criteria in Solid Tumors [RECIST]) Versus RECIST 1.1 in patients with advanced hepatocellular carcinoma treated with sorafenib

INTRODUCTION

Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST 1.1), may underestimate activity and does not predict survival in patients with hepatocellular carcinoma (HCC) treated with sorafenib. This study assessed the value of alternative radiological criteria to evaluate response in HCC patients treated with sorafenib.

PATIENTS AND METHODS

A retrospective blinded central analysis was performed of computed tomography (CT) scans from baseline and the first tumor evaluation in consecutive patients treated with sorafenib over a 2-year period in a single institution. Four different evaluation criteria were used: Choi, European Association for the Study of the Liver (EASL), modified RECIST (mRECIST), and RECIST 1.1.

RESULTS

Among 82 HCC patients, 64 with Barcelona Clinic Liver Cancer stage B-C were evaluable with a median follow-up of 22 months. Median duration of sorafenib treatment was 5.7 months, and median overall survival was 12.8 months. At the time of the first CT scan, performed after a median of 2.1 months, Choi, EASL, mRECIST, and RECIST 1.1 identified 51%, 28%, 28%, and 3% objective responses, respectively. Responders by all criteria showed consistent overall survival >20 months. Among patients with stable disease according to RECIST 1.1, those identified as responders by Choi had significantly better overall survival than Choi nonresponders (22.4 vs. 10.6 months; hazard ratio: 0.43, 95% confidence interval: 0.15-0.86, p = .0097).

CONCLUSION

Choi, EASL, and mRECIST criteria appear more appropriate than RECIST 1.1 to identify responders with long survival among advanced HCC patients benefiting from sorafenib.

Drug-eluting beads loaded with antiangiogenic agents for chemoembolization: in vitro sunitinib loading and release and in vivo pharmacokinetics in an animal model

PURPOSE

The combination of embolic beads with a multitargeted tyrosine kinase inhibitor that inhibits tumor vessel growth is suggested as an alternative and improvement to the current standard doxorubicin-eluting beads for use in transarterial chemoembolization. This study demonstrates the in vitro loading and release kinetics of sunitinib using commercially available embolization microspheres and evaluates the in vitro biologic efficacy on cell cultures and the resulting in vivo pharmacokinetics profiles in an animal model.

MATERIALS AND METHODS

DC Bead microspheres, 70-150 µm and 100-300 µm (Biocompatibles Ltd., Farnham, United Kingdom), were loaded by immersion in sunitinib solution. Drug release was measured in saline in a USP-approved flow-through apparatus and quantified by spectrophotometry. Activity after release was confirmed in cell culture. For pharmacokinetics and in vivo toxicity evaluation, New Zealand white rabbits received sunitinib either by intraarterial injection of 100-300 µm sized beads or per os. Plasma and liver tissue drug concentrations were assessed by liquid chromatography-tandem mass spectroscopy.

RESULTS

Sunitinib loading on beads was close to complete and homogeneous. A total release of 80% in saline was measured, with similar fast-release profiles for both sphere sizes. After embolization, drug plasma levels remained below the therapeutic threshold (< 50 ng/mL), but high concentrations at 6 hours (14.9 µg/g) and 24 hours (3.4 µg/g) were found in the liver tissue.

CONCLUSIONS

DC Bead microspheres of two sizes were efficiently loaded with sunitinib and displayed a fast and almost complete release in saline. High liver drug concentrations and low systemic levels indicated the potential of sunitinib-eluting beads for use in embolization.

Imaging response in neuroendocrine tumors treated with targeted therapies: the experience of sunitinib

Among neuroendocrine carcinomas of the gut, well-differentiated tumors are highly vascularized, featuring specific characteristics on contrast-enhanced imaging. Well-differentiated neuroendocrine tumors spontaneously harbor hypervascular enhancement, coexisting with areas of necrosis mainly located at the center of tumor lesions. When exposed to vascular endothelial growth factor (VEGFR) inhibitors such as sunitinib, target lesions display few if any variation in tumor size, but rather detectable modifications in tumor density. In several patients treated with targeted therapy, a significant decrease of tumor density at first tumor evaluation can be detected as compared to baseline. Consistently, the two randomized trials leading to approval of sunitinib and everolimus in pancreatic neuroendocrine tumors report objective response rate below 10%, emphasizing that Response Evaluation Criteria in Solid Tumors (RECIST), that focus only on the largest diameters of target lesions, may be insufficient to capture the full benefit of targeted therapies. Alternative criteria, such as those developed by Choi et al., consider both the size and the density of the tumor as parameters for response evaluation. Choi criteria have been recently proposed as a surrogate endpoint for efficacy and to identify patients that are good responders to VEGFR inhibitors such as sunitinib and sorafenib in advanced hepatocellular carcinoma, another disease highly addicted to angiogenesis. Preliminary data generated from patients included in the sunitinib phase III trial suggest that Choi criteria might also be considered as an alternative to RECIST to evaluate the effects of sunitinib in patients with advanced well-differentiated neuroendocrine tumors.

Transarterial chemoembolization plus or minus intravenous bevacizumab in the treatment of hepatocellular cancer: a pilot study

Background

Stimulation of vascular endothelial growth factor (VEGF) has been observed following transarterial chemoembolization (TACE) in hepatocellular cancer (HCC) and may contribute to tumor regrowth. This pilot study examined whether intravenous (IV) bevacizumab, a monoclonal antibody against VEGF, could inhibit neovessel formation after TACE.

Methods

30 subjects with HCC undergoing TACE at a single academic institution were randomized with a computer-generated allocation in a one to one ratio to either bevacizumab at a dose of 10 mg/kg IV every 14 days beginning 1 week prior to TACE (TACE-BEV arm) or observation (TACE-O arm). Angiography was performed with TACE at day 8, and again at weeks 10 and 14. Repeat TACE was performed at week 14 if indicated. TACE-BEV subjects were allowed to continue bevacizumab beyond week 16. TACE-O subjects were allowed to cross-over to bevacizumab at week 16 in the setting of progressive disease. The main outcome measure was a comparison of neovessel formation by serial angiography. Secondary outcome measures were progression free survival (PFS) at 16 weeks, overall survival (OS), bevacizumab safety, and an analysis of VEGF levels before and after TACE with and without bevacizumab.

Results

Among the 30 subjects enrolled, 9 of 15 randomized to the TACE-O arm and 14 of 15 randomized to the TACE-BEV arm completed all 3 angiograms. At week 14, 3 of 9 (33%) TACE-O subjects and 2 of 14 (14%) TACE-BEV subjects demonstrated neovascularity. The PFS at 16 weeks was 0.19 in the TACE-O arm and 0.79 in the TACE-BEV arm (p = 0.021). The median OS was 61 months in the TACE-O arm and 49 months in the TACE-BEV arm (p = 0.21). No life-threatening bevacizumab-related toxicities were observed. There were no substantial differences in bevacizumab pharmacokinetics compared to historical controls. Bevacizumab attenuated the increase in VEGF observed post-TACE.

Conclusions

IV bevacizumab was well tolerated in selected HCC subjects undergoing TACE, and appeared to diminish neovessel formation at week 14.

Trial registration

ClinicalTrials.gov NCT00049322.

Changes in tumor density in patients with advanced hepatocellular carcinoma treated with sunitinib

PURPOSE

Response Evaluation Criteria in Solid Tumors (RECIST) may underestimate the efficacy of targeted therapies. In hepatocellular carcinoma (HCC) studies with sunitinib, RECIST-defined response rates are low, although hypodensity on computed tomography (CT) scans occurs more frequently. This exploratory analysis investigated tumor density as a surrogate endpoint of sunitinib activity in a phase II HCC study.

EXPERIMENTAL DESIGN

Patients received sunitinib 50 mg/d (4 weeks on/2 weeks off). Tumor size and density were assessed on CT scans by using RECIST and Choi criteria, the latter of which classify a partial response as a 15% or more reduction in tumor density or a 10% or more reduction in tumor size. The overall percentage volume of tumor necrosis was calculated with volumetric reconstruction. Tumor perfusion parameters were assessed by using perfusion CT scans with specific acquisition.

RESULTS

Among the 26 evaluable patients, 1 achieved a partial response and 22 had tumor stabilization by RECIST. In analysis of tumor density, 17 of 26 patients (65.4%) were responders by Choi criteria. Volumetric assessment showed major tumor necrosis (≥30% of tumor volume) in 10 of 21 patients (47.6%). Among four patients evaluated, tumor blood flow was reduced by 58.8% and blood volume by 68.4% after 4 weeks of treatment. The median time to progression (TTP) was 6.4 months. Patients with responses by Choi criteria had a significantly longer TTP (7.5 months) compared with nonresponders (4.8 months; HR = 0.33, two-sided P = 0.0182).

CONCLUSIONS

Tumor density assessment suggested that radiologic endpoints in addition to RECIST may be considered to capture sunitinib activity in HCC.

HCC and angiogenesis: possible targets and future directions

Hepatocellular carcinoma (HCC), the most common primary liver tumor, is notoriously resistant to systemic therapies, and often recurs even after aggressive local therapies. HCCs rely on the formation of new blood vessels for growth, and VEGF is critical in this process. A hallmark of new vessel formation in tumors is their structural and functional abnormality. This leads to an abnormal tumor microenvironment characterized by low oxygen tension. The liver is perfused by both arterial and venous blood and the resulting abnormal microenvironment selects for more-aggressive malignancies. Anti-VEGF therapy with sorafenib was the first systemic therapy to demonstrate improved survival in patients with advanced-stage HCC. This important development in the treatment of HCC raises hope as well as critical questions on the future development of targeted agents including other antiangiogenic agents, which hold promise to further increase survival in this aggressive disease.

Liver cancer: Targeted future options

Hepatocellular carcinoma (HCC) has a poor prognosis and systemic chemotherapies have disappointing results. The increasing knowledge of the molecular biology of HCC has resulted in novel targets, with the vascular endothelial growth factor and epidermal growth factor receptor (EGFR)-related pathways being of special interest. New blood vessel formation (angiogenesis) is essential for the growth of solid tumors. Anti-angiogenic strategies have become an important therapeutic modality for solid tumors. Several agents targeting angiogenesis-related pathways have entered clinical trials or have been already approved for the treatment of solid tumors. These include monoclonal antibodies, receptor tyrosine kinase inhibitors and immunomodulatory drugs. HCC is a highly vascular tumor, and angiogenesis is believed to play an important role in its development and progression. This review summarizes recent advances in the basic understanding of the role of angiogenesis in HCC as well as clinical trials with novel therapeutic approaches targeting angiogenesis and EGFR-related pathways.

Benefits from pharmacological and pharmacokinetic properties of sunitinib for clinical development

IMPORTANCE OF THE FIELD

In the last 10 years, oncology has been greatly modified by the introduction of new drugs especially designed for molecular targets. Sunitinib belongs to the category of new drugs that inhibit multityrosine kinase receptors involved in the key steps of tumorigenesis and angiogenesis.

AREAS COVERED IN THIS REVIEW

This article reviews the pharmacological and clinical aspects of sunitinib. Literature search was conducted in PubMed, and articles selected for relevance to pharmacology or clinical efficacy up to March 2010.

WHAT THE READER WILL GAIN

Pharmacology of sunitinib, data regarding clinical efficacy, and challenges to overcome resistance and improve outcomes of patients.

TAKE HOME MESSAGE

Sunitinib is an oral small molecule that displays mainly antiangiogenic properties and also direct antitumoral effects. Being well tolerated, this small molecule is now an essential treatment of advanced renal cell carcinoma and gastrointestinal stromal tumors refractory or intolerant to imatinib, two localizations associated with a poor prognosis. Future developments include the extension of the indications of sunitinib in pancreatic neuroendocrine tumors, the evaluation of combinations with conventional cytotoxic and other targeted drugs and the development of strategy to overcome resistance to sunitinib.

Novel inhibitors in development for hepatocellular carcinoma

IMPORTANCE OF THE FIELD

The multikinase inhibitor sorafenib was the first agent to demonstrate a survival benefit for patients with locally advanced or metastatic hepatocellular carcinoma (HCC). Although sorafenib represents a landmark in the treatment of HCC and proved molecularly targeted therapy to be effective in this disease, it represents just the first step towards an improvement in systemic therapy. Since then, novel inhibitors have been evaluated in early clinical trials, showing potential activity.

AREAS COVERED IN THIS REVIEW

This article aims to review novel inhibitors emerging in the field of advanced HCC. An Internet-based search was performed to identify abstracts, clinical trials ( www.clinicaltrials.gov , last accessed 30 November 2009), and original research and review articles.

WHAT THE READER WILL GAIN

Readers will gain a comprehensive survey of current molecularly targeted therapy approaches in advanced HCC. In addition, challenges such as the design of clinical trials, the assessment of radiological response, the role of combination therapy, and future developments in molecularly targeted therapy are discussed.

TAKE HOME MESSAGE

Sorafenib is the standard of care in patients with advanced HCC. However, promising novel inhibitors are under investigation. Combined molecularly targeted therapies according to an individual genomic and proteomic profiling will probably lead to more personalised medicine in advanced HCC.

[Targeted therapies in hepatocellular carcinoma]

Hepatocellular carcinoma (HCC) stands as a major health problem worldwide. The management of advanced HCC, limited for a longtime by the disappointing results of conventional cytotoxic chemotherapies, has recently changed with the publication of the results of the Sorafenib Hepatocellular Carcinoma Assessment Randomized Protocol (SHARP) trial, which demonstrated an overall survival benefit over placebo in patients with advanced HCC. This study was further confirmed by the Asian-Pacific trial using sorafenib in Eastern patients. Those trials demonstrated that therapeutic benefits may derive from improving our knowledge of deregulated signaling pathways involved in HCC carcinogenesis. This review summarizes the results of clinical trials in which targeted therapies are currently evaluated aiming to enlarge the therapeutic armamentarium for HCC in a near future.