Sequential systemic treatment in patients with hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most lethal cancers. After many years of stagnation, there are now several systemic treatments available for patients with HCC.

AIM

To analyse the feasibility and efficacy of sequential systemic treatments in patients with HCC in clinical practice.

METHODS

In this multicentre study, patients who were treated with novel systemic therapies for HCC between 2014 and 2019 at two referral centres, Hannover Medical School, Germany, and Medical University of Vienna, Austria, were included.

RESULTS

Overall, 85 patients were included of which 76 patients (89.4%) received more than one and a maximum of five systemic treatment lines. The most common therapy sequence was sorafenib (n = 72; 84.7%) followed by regorafenib (n = 37; 48.7%), whereas 11 patients were initially treated with lenvatinib (12.9%). Other second-line treatments included pembrolizumab, nivolumab, cabozantinib and ramucirumab. Hepatic function deteriorated during sequential systemic treatment in 48.6% of the patients as defined by an increase in at least one Child-Pugh point. Median overall survival (mOS) from the start of first systemic treatment was 35 months for patients with sequential systemic treatment compared to 9 months for patients with one systemic treatment line (P < 0.001). Patients previously treated with surgical/locoregional therapies had a longer mOS compared to patients with initial systemic treatment (66 vs 25 months; P = 0.020).

CONCLUSIONS

Sequential systemic treatment is feasible and effective in selected patients with HCC in clinical practice. Our study underlines the critical importance of well-preserved liver function for successful administration of sequential systemic therapy.

A meta-analysis comparing responses of Asian versus non-Asian cancer patients to PD-1 and PD-L1 inhibitor-based therapy

Background

Subgroup analysis of clinical trials of PD-1/PD-L1 inhibitors have reported ethnic differences in outcomes. We systematically collected published data and performed a meta-analysis to compare therapeutic efficacy in Asian and non-Asian patients receiving PD-1/PD-L1 inhibitors.

Methods

Eligible studies included phase II and III prospective clinical trials with available subgroup data on Asian versus non-Asian populations. Overall survival (OS) and progression-free survival (PFS) were used to evaluate differences in outcome between Asian versus non-Asian cancer patients.

Results

A total of 11,020 cancer patients from 19 prospective randomized controlled clinical trials were included. The overall estimated HR for OS was 0.69 with 95% CI of 0.61-0.77 in Asian versus 0.82 with 95% CI of 0.77-0.88 in non-Asian patients. The estimated hazard ratio (HR) for PFS measured 0.54 (95% CI, 0.32-0.76) and 0.69 (95% CI, 0.54-0.85) in Asian and non-Asian patients, respectively. Pooled ratios of OS HRs and PFS HRs reported in Asian versus non-Asian cancer patients were 0.84 (95% CI, 0.75-0.94) and 0.78 (95% CI, 0.59-0.97), respectively.

Conclusions

This meta-analysis shows for the first time that Asian cancer patients have a significantly improved survival benefit than non-Asian patients receiving PD-1/PD-L1 inhibitor-based therapy.

Obesity and Cancer Treatment Outcomes: Interpreting the Complex Evidence

A wealth of epidemiological evidence, combined with plausible biological mechanisms, present a convincing argument for a causal relationship between excess adiposity, commonly approximated as body mass index (BMI, kg/m²), and incident cancer risk. Beyond this relationship, there are a number of challenges posed in the context of interpreting whether being overweight (BMI 25.0-29.9 kg/m²) or obese (BMI ≥ 30.0 kg/m²) adversely influences disease progression, cancer mortality and survival. Elevated BMI (≥ 25.0 kg/m²) may influence treatment selection of, for example, the approach to surgery; the choice of chemotherapy dosing; the inclusion of patients into randomised clinical trials. Furthermore, the technical challenges posed by an elevated BMI may adversely affect surgical outcomes, for example, morbidity (increasing the risk of surgical site infections), reduced lymph node harvest (and subsequent risk of under-staging and under-treatment) and increased risk of margin positivity. Suboptimal chemotherapy dosing, associated with capping chemotherapy in obese patients as an attempt to avoid excess toxicity, might be a driver of poor prognostic outcomes. By contrast, the efficacy of immune checkpoint inhibition may be enhanced in patients who are obese, although in turn, this observation might be due to reverse causality. So, a central research question is whether being overweight or obese adversely affects outcomes either directly through effects of cancer biology or whether adverse outcomes are mediated through indirect pathways. A further dimension to this complex relationship is the obesity paradox, a phenomenon where being overweight or obese is associated with improved survival where the reverse is expected. In this overview, we describe a framework for evaluating methodological problems such as selection bias, confounding and reverse causality, which may contribute to spurious interpretations. Future studies will need to focus on prospective studies with well-considered methodology in order to improve the interpretation of causality.

Hepatocellular carcinoma: recent advances and emerging medical therapies

Hepatocellular carcinoma remains a deadly disease with poor prognosis in patients with unresectable cancer. Trans-arterial chemoembolization is the primary locoregional therapy for intermediate-stage hepatocellular carcinoma, with an estimated median overall survival of less than two years. For almost a decade, sorafenib has been the only standard systemic treatment for metastatic disease or tumors which progress or are considered unsuitable for locoregional therapy. Major breakthroughs have been made over the past few years in the management of hepatocellular carcinoma, especially in medical therapies for advanced disease. In this article, recent advances in intra-arterial therapy, multi-kinase inhibitors, and immunotherapy will be reviewed.

Immune Checkpoint Inhibitors in Hepatocellular Cancer: Current Understanding on Mechanisms of Resistance and Biomarkers of Response to Treatment

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy worldwide and a leading cause of death worldwide. Its incidence continues to increase in the US due to hepatitis C infection and nonalcoholic steatohepatitis. Liver transplantation and resection remain the best therapeutic options for cure, but these are limited by the shortage of available organs for transplantation, diagnosis at advanced stage, and underlying chronic liver disease found in most patients with HCC. Immune checkpoint inhibitors (ICIs) have been shown to be an evolving novel treatment option in certain advanced solid tumors and have been recently approved for inoperable, advanced, and metastatic HCC. Unfortunately, a large cohort of patients with HCC fail to respond to immunotherapy. In this review, we discuss the ICIs currently approved for HCC treatment and their various mechanisms of action. We will highlight current understanding of mechanism of resistance and limitations to ICIs. Finally, we will describe emerging biomarkers of response to ICIs and address future direction on overcoming resistance to immune checkpoint therapy.

Profile of Cabozantinib for the Treatment of Hepatocellular Carcinoma: Patient Selection and Special Considerations

Management of advanced hepatocellular carcinoma is challenging. With an increasing number of options for the first and second-line treatment, understanding and developing optimal systemic treatment strategies are crucial. In second line, two tyrosine kinase inhibitors (TKI) and one monoclonal antibody have been approved after sorafenib by both the European Medicines Agency and the Food and Drug Administration based on the results of phase 3 trials: cabozantinib, regorafenib and ramucirumab. Cabozantinib has demonstrated an improved overall survival and progression-free survival in the phase 3 CELESTIAL study in second and third line, in patients in good general condition (performance status 0-1) and with a normal liver function Child-Pugh class A. Analysis of subgroups has shown that even elderly patients over 65 years, or patients with high baseline alpha-fetoprotein ≥400 ng/mL benefit from cabozantinib. The choice in second-line between the three drugs should be based on factors such as previous tolerance of sorafenib, safety profile of drugs and quality of life. In this review, we will analyze clinical data available on cabozantinib, clarifying the choice between the different possible treatments. However, the upcoming of a new standard in first line with the combination atezolizumab and bevacizumab will change the game and will warrant further investigations to define the accurate subsequent sequence of TKIs. Cabozantinib is also actually tested in first-line in combination with atezolizumab, results of the phase 3 COSMIC trial are eagerly awaited.

Cabozantinib in combination with atezolizumab versus sorafenib in treatment-naive advanced hepatocellular carcinoma: COSMIC-312 Phase III study design

Cabozantinib is an oral tyrosine kinase inhibitor that targets VEGFR, MET and the TAM (TYRO3, AXL, MER) family of kinase receptors. In addition to their role in tumor growth and angiogenesis, cabozantinib targets promote an immune-suppressive microenvironment. Cabozantinib is approved as single-agent therapy for patients with advanced hepatocellular carcinoma who received prior sorafenib. Owing to its antitumor and immunomodulatory properties, cabozantinib is being developed in combination with immune checkpoint inhibitors. Early studies of these combinations have shown promising antitumor activity and tolerability in patients with solid tumors. Here, we describe the rationale and design of COSMIC-312, a Phase III study evaluating the safety and efficacy of cabozantinib in combination with atezolizumab (anti-PD-L1 monoclonal antibody) versus sorafenib for treatment-naive patients with advanced hepatocellular carcinoma. ClinicalTrial.gov Registration: NCT03755791.

Role of Molecular Biomarkers in Liver Transplantation for Hepatocellular Carcinoma

Patient selection and organ allocation for liver transplantation (LT) in patients with hepatocellular carcinoma (HCC) relies predominantly on clinical parameters, such as tumor burden (ie, radiological imaging). Patients transplanted within Milan criteria have outstanding outcomes with a 5- and 10-year survival of 70% and 55%, respectively. Tumor recurrence after transplantion is rare in these patients (10%); however, treatment options upon recurrence are generally limited, and outcomes are poor. There are also several studies showing how a subgroup of patients with tumors outside the Milan criteria might achieve comparable outcomes to patients within Milan criteria. In other words, the size and number of tumor nodules does not always reflect tumor biology, which could be better captured using molecular proxies for cancer aggressiveness. Over the last decade, we have significantly improved our understanding of the molecular landscape of early stage HCC. This includes the development of molecular classification, identification of prognostic and mutational signatures, and potential mechanisms of hepatocarcinogenesis. Some molecular markers have already proven useful to predict tumor-related outcomes in HCC patients after LT. Most of these analyses are limited to tissue-derived biomarkers, which limits their implementation in clinical practice because tissue biopsy is not required for HCC diagnosis. Minimally invasive alternative tools, such as liquid biopsy, are being increasingly explored and could help to individualize risk stratification for patients with HCC who will benefit from LT despite being outside the accepted clinical criteria.

Immunotherapy in gastrointestinal cancer: The current scenario and future perspectives

Gastrointestinal cancers include colorectal, gastric, oesophageal, pancreatic and liver cancers. They continue to be a significant cause of mortality and morbidity worldwide. Current treatment strategies include chemotherapy, surgery, radiotherapy and targeted therapies. Immunotherapy has recently been incorporated in treatment regimens for some gastrointestinal malignancies and research into different immune modifying treatments is being carried out in this context. Approaches to immune modulation such as vaccination, adoptive cell therapy and checkpoint inhibition have shown varying clinical benefit, with most of the benefit seen in checkpoint inhibition. This review summarises recent advances and future direction of immunotherapy in patients with gastrointestinal malignancies.

Anti-PD-1/PD-L1 Blockade Immunotherapy Employed in Treating Hepatitis B Virus Infection-Related Advanced Hepatocellular Carcinoma: A Literature Review

Hepatitis B virus (HBV) infection is regarded as the main etiological risk factor in the process of hepatocellular carcinoma (HCC), as it promotes an immunosuppressive microenvironment that is partially mediated by the programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) signaling pathway. The tumor microenvironment (TME) of HBV-related HCC is indeed more immunosuppressive than microenvironments not associated with viruses. And compared to TME in hepatitis C virus (HCV) infected HCC, TME of HBV-related HCC is less vascularized and presents different immune components resulting in similar immunosuppression. However, few studies are focusing on the specific side effects and efficacy of PD-1/PD-L1 blockade immunotherapy in HBV-related HCC patients, as well as on the underlying mechanism. Herein, we reviewed the basic research focusing on potential TME alteration caused by HBV infection, especially in HCC patients. Moreover, we reviewed PD-1/PD-L1 blockade immunotherapy clinical trials to clarify the safety and efficacy of this newly developed treatment in the particular circumstances of HBV infection. We found that patients with HBV-related HCC displayed an acceptable safety profile similar to those of non-infected HCC patients. However, we could not determine the antiviral activity of PD-1/PD-L1 blockade because standard anti-viral therapies were conducted in all of the current clinical trials, which made it difficult to distinguish the potential influence of PD-1/PD-L1 blockade on HBV infection. Generally, the objective response rates (ORRs) of PD-1/PD-L1 blockade immunotherapy did not differ significantly between virus-positive and virus-negative patients, except that disease control rates (DCRs) were obviously lower in HBV-infected HCC patients.

Ramucirumab, A Second-Line Option For Patients With Hepatocellular Carcinoma: A Review Of The Evidence

Hepatocellular carcinoma (HCC) is the most frequent primary liver cancer and predominantly develops in patients with liver cirrhosis. In patients with advanced disease, such as extra-hepatic extension or portal vein involvement, and with intermediate disease unsuitable for locoregional therapies, systemic therapy is recommended, if liver function and performance status are adequate. Following a decade of negative Phase III trials since the approval of sorafenib, more recently several drugs have proven efficacy both in first line versus sorafenib (lenvatinib) or in second line versus placebo (regorafenib, cabozantinib, ramucirumab). In this review, we summarize the preclinical and clinical evidence supporting the use of ramucirumab, a recombinant IgG1 monoclonal antibody that specifically binds to Vascular Endothelial Growth Factor receptor 2 (VEGFR-2), in HCC. Following the results of the REACH trial, that was negative in the overall study population but identified a subgroup that could benefit from ramucirumab treatment, the REACH-2 trial was a randomized, placebo-controlled trial, designed to assess ramucirumab as second line in patients with alpha-fetoprotein (AFP) ≥400 ng/mL. The results of REACH-2 were published in February 2019, leading to Food and Drug Administration and European Medicines Agency approval of the drug as second-line agent for advanced HCC (after sorafenib) in patients with AFP ≥400 ng/mL. For the first time in the history of systemic treatments for HCC, a predictive factor of efficacy was identified. In this review, we also discuss the potential clinical development of systemic treatments in HCC, focusing on combination therapies with immunotherapy (following the recent results of the combination of atezolizumab and bevacizumab in the IMbrave 150 clinical trial) and treatment sequences as a way to maximize survival benefit.

Immune Phenotype and Immune Checkpoint Inhibitors for the Treatment of Human Hepatocellular Carcinoma

Immunotherapies are promising approaches for treating hepatocellular carcinomas (HCCs) refractory to conventional therapies. However, a recent clinical trial of immune checkpoint inhibitors (ICIs) revealed that anti-tumor responses to ICIs are not satisfactory in HCC cases. Therefore, it is critical to identify molecular markers to predict outcome and develop novel combination therapies that enhance the efficacy of ICIs. Recently, several attempts have been made to classify HCC based on genome, epigenome, and transcriptome analyses. These molecular classifications are characterized by unique clinical and histological features of HCC, as well immune phenotype. For example, HCCs exhibiting gene expression patterns with proliferation signals and stem cell markers are associated with the enrichment of immune infiltrates in tumors, suggesting immune-proficient characteristics for this type of HCC. However, the presence of activating mutations in β-catenin represents a lack of immune infiltrates and refractoriness to ICIs. Although the precise mechanism that links the immunological phenotype with molecular features remains controversial, it is conceivable that alterations of oncogenic cellular signaling in cancer may lead to the expression of immune-regulatory molecules and result in the acquisition of specific immunological microenvironments for each case of HCC. Therefore, these molecular and immune characteristics should be considered for the management of HCC using immunotherapy.

Atezolizumab plus Bevacizumab in Unresectable Hepatocellular Carcinoma

BACKGROUND

The combination of atezolizumab and bevacizumab showed encouraging antitumor activity and safety in a phase 1b trial involving patients with unresectable hepatocellular carcinoma.

METHODS

In a global, open-label, phase 3 trial, patients with unresectable hepatocellular carcinoma who had not previously received systemic treatment were randomly assigned in a 2:1 ratio to receive either atezolizumab plus bevacizumab or sorafenib until unacceptable toxic effects occurred or there was a loss of clinical benefit. The coprimary end points were overall survival and progression-free survival in the intention-to-treat population, as assessed at an independent review facility according to Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST 1.1).

RESULTS

The intention-to-treat population included 336 patients in the atezolizumab-bevacizumab group and 165 patients in the sorafenib group. At the time of the primary analysis (August 29, 2019), the hazard ratio for death with atezolizumab-bevacizumab as compared with sorafenib was 0.58 (95% confidence interval [CI], 0.42 to 0.79; P<0.001). Overall survival at 12 months was 67.2% (95% CI, 61.3 to 73.1) with atezolizumab-bevacizumab and 54.6% (95% CI, 45.2 to 64.0) with sorafenib. Median progression-free survival was 6.8 months (95% CI, 5.7 to 8.3) and 4.3 months (95% CI, 4.0 to 5.6) in the respective groups (hazard ratio for disease progression or death, 0.59; 95% CI, 0.47 to 0.76; P<0.001). Grade 3 or 4 adverse events occurred in 56.5% of 329 patients who received at least one dose of atezolizumab-bevacizumab and in 55.1% of 156 patients who received at least one dose of sorafenib. Grade 3 or 4 hypertension occurred in 15.2% of patients in the atezolizumab-bevacizumab group; however, other high-grade toxic effects were infrequent.

CONCLUSIONS

In patients with unresectable hepatocellular carcinoma, atezolizumab combined with bevacizumab resulted in better overall and progression-free survival outcomes than sorafenib. (Funded by F. Hoffmann-La Roche/Genentech; ClinicalTrials.gov number, NCT03434379.).

IMbrave 050: a Phase III trial of atezolizumab plus bevacizumab in high-risk hepatocellular carcinoma after curative resection or ablation

Hepatocellular carcinoma recurs in 70-80% of cases following potentially curative resection or ablation and the immune component of the liver microenvironment plays a key role in recurrence. Many immunosuppressive mechanisms implicated in HCC recurrence are modulated by VEGF and/or immune checkpoints such as PD-L1. Atezolizumab (PD-L1 inhibitor) plus bevacizumab (VEGF inhibitor) has been shown to significantly improve overall survival, progression-free survival and overall response rate in unresectable HCC. Dual PD-L1/VEGF blockade may be effective in reducing HCC recurrence by creating a more immune-favorable microenvironment. We describe the rationale and design of IMbrave 050 (NCT04102098), a randomized, open-label, Phase III study comparing atezolizumab plus bevacizumab versus active surveillance in HCC patients at high-risk of recurrence following curative resection or ablation. The primary end point is recurrence-free survival. Clinical Trial Registration: NCT04102098.

Scientific Rationale for Combined Immunotherapy with PD-1/PD-L1 Antibodies and VEGF Inhibitors in Advanced Hepatocellular Carcinoma

A successful phase III trial for the combination of atezolizumab and bevacizumab (the IMbrave150 trial) in advanced hepatocellular carcinoma has recently been reported. This is groundbreaking because nivolumab and pembrolizumab, both programmed cell death-1 (PD-1) antibodies, have failed to show efficacy as first- and second-line therapeutics, respectively, in phase III clinical trials. Immunotherapy with a combination of atezolizumab and bevacizumab resulted in better survival than treatment with sorafenib for the first time since sorafenib was approved in 2007. The high efficacy of the combination of PD-1/programmed death ligand 1 (PD-L1) and vascular endothelial growth factor (VEGF) antibodies is not only due to their additive effects on tumor growth, but also to their reprogramming of the immunosuppressive microenvironment into an immunostimulatory microenvironment. These results were confirmed in a phase Ib trial that showed significantly longer progression-free survival in the atezolizumab plus bevacizumab group than in patients that received atezolizumab alone. These results demonstrate that immunotherapy with a combination of PD-1/PD-L1 and VEGF inhibitors is effective and may result in a reprogramming of the tumor microenvironment. The results of an ongoing phase III trial of a PD-1 antibody in combination with the VEGF receptor tyrosine kinase inhibitor (TKI) are highly anticipated.

Mouse Models of Oncoimmunology in Hepatocellular Carcinoma

Liver cancer is the fourth leading cause of cancer-related mortality worldwide and incidence is on the rise. Hepatocellular carcinoma (HCC) is the most common form of liver cancer, with a complex etiology and limited treatment options. The standard-of-care treatment for patients with advanced HCC is sorafenib, a tyrosine kinase inhibitor that offers limited survival benefit. In the past years, therapeutic options for the treatment of advanced HCC have increased substantially, including additional multikinase inhibitors as well as immune checkpoint inhibitors. Nivolumab and pembrolizumab were approved in 2017 and 2018, respectively, as second-line treatment in advanced HCC. These drugs, both targeting the programmed death-1 pathway, demonstrate unprecedented results, with objective response rates of approximately 20%. However, the majority of patients do not respond, necessitating the identification of biomarkers of response and resistance to immunotherapy. With the recent success of immunotherapies in oncology, mouse models that better recapitulate the human disease and antitumor immune response are needed. This review lists ongoing clinical trials testing immunotherapy in HCC, briefly discusses the unique immunosuppressive environment of the liver, and then delves into the most applicable current murine model systems to study oncoimmunology within the context of HCC, including syngeneic, genetically engineered, and humanized models.

The Crosstalk between Tumor Cells and the Microenvironment in Hepatocellular Carcinoma: The Role of Exosomal microRNAs and their Clinical Implications

The communication between hepatocellular carcinoma (HCC) cells and their microenvironment is an essential mechanism supporting or preventing tumor development and progression. Recent evidence has identified extracellular vesicles (EVs) as one of the mechanisms mediating paracrine signaling between cells. Exosomes, the most described class of EVs, deliver proteins, mRNAs, noncoding RNAs, DNA, and lipids to recipient cells, also at remote distances. MicroRNAs (miRNAs), as part of the non-coding RNA exosomal cargo, have an important role in regulating cellular pathways in targeted cells, regulating several processes related to tumor progression invasion and metastasis, such as angiogenesis, immune-escape, epithelial-to-mesenchymal transition, invasion, and multi-drug resistance. Accumulating evidence suggests exosomal miRNAs as relevant players in the dynamic crosstalk among cancerous, immune, and stromal cells in establishing the tumorigenic microenvironment. In addition, they sustain the metastasic niche formation at distant sites. In this review, we summarized the recent findings on the role of the exosome-derived miRNAs in the cross-communication between tumor cells and different hepatic resident cells, with a focus on the molecular mechanisms responsible for the cell re-programming. In addition, we describe the clinical implication derived from the exosomal miRNA-driven immunomodulation to the current immunotherapy strategies and the molecular aspects influencing the resistance to therapeutic agents.

Recent Advances in Immunotherapy for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death since most patients are diagnosed at advanced stage and the current systemic treatment options using molecular-targeted drugs remain unsatisfactory. However, the recent success of cancer immunotherapies has revolutionized the landscape of cancer therapy. Since HCC is characterized by metachronous multicentric occurrence, immunotherapies that induce systemic and durable responses could be an appealing treatment option. Despite the suppressive milieu of the liver and tumor immunosurveillance escape mechanisms, clinical studies of checkpoint inhibitors in patients with advanced HCC have yielded promising results. Here, we provide an update on recent advances in HCC immunotherapies. First, we describe the unique tolerogenic properties of hepatic immunity and its interaction with HCC and then review the status of already or nearly available immune checkpoint blockade-based therapies as well as other immunotherapy strategies at the preclinical or clinical trial stage.

Nivolumab for Advanced Hepatocellular Carcinoma with Multiple Lung Metastases after Sorafenib Failure

Over the past decade, standard first-line systemic treatment of advanced hepatocellular carcinoma (HCC) has been based on sorafenib, a multi-kinase inhibitor. Regorafenib, another tyrosine kinase inhibitor, is the only second-line therapy that has been globally approved after progression under sorafenib treatment. Recently, immunotherapeutic agents have emerged as promising treatment options in many different malignancies, including advanced HCC. Nivolumab is the first immunotherapy approved by the Food and Drug Administration for use in HCC patients with advanced-stage second-line after sorafenib failure. In this report, a case of advanced HCC with multiple lung metastases in which a complete response and maintained progression-free status was achieved with nivolumab, following the failure of transarterial chemoembolization and sorafenib is presented. We hope this report may help expand the clinical application of second-line treatment.

Challenges of combination therapy with immune checkpoint inhibitors for hepatocellular carcinoma

Immune checkpoint inhibitor (ICI) therapy targeting anti-programmed cell death-1 (anti-PD-1) or its ligand (anti-PD-L1) is the backbone of numerous combination regimens aimed at improving the objective response and survival of patients with hepatocellular carcinoma (HCC). Clinical trials of immuno-oncology regimens in other cancer types have shed light on issues of study design, including how to choose candidate regimens based on early-phase trial results, statistical considerations in trials with multiple primary endpoints, and the importance of predictive biomarkers. In this review, the updated data from early-phase trials of combination immunotherapy for HCC are summarised. Since the most extensively tested combination regimens for advanced HCC comprise anti-PD-1/anti-PD-L1 agents plus antiangiogenic agents, the relative benefit and antitumor mechanism of antiangiogenic multikinase inhibitors versus specific VEGF/VEGFR inhibitors are discussed. Other critical issues in the development of combination immunotherapy, including optimal management of immune-related adverse events and the value of ICI therapy in combination with locoregional treatment for HCC, are also explored.

Molecular therapies for HCC: Looking outside the box

Over the past decade, sorafenib has been the only systemic agent with proven clinical efficacy for patients with unresectable hepatocellular carcinoma (HCC). Recently, lenvatinib was shown to be non-inferior to sorafenib, while regorafenib, cabozantinib, and ramucirumab were shown to be superior to placebo in patients failing sorafenib. In addition, trials of immune checkpoint inhibitors reported encouraging efficacy signals. However, apart from alpha-fetoprotein, which is used to select patients for ramucirumab, no biomarkers are available to identify patients that may respond to a specific treatment. Different synergisms have been postulated based on the potential interplay between antiangiogenic drugs and immunotherapy, with several clinical trials currently testing this hypothesis. Indeed, encouraging preliminary results of phase I studies of bevacizumab plus atezolizumab and lenvatinib plus pembrolizumab have led to the design of ongoing phase III trials, including both antiangiogenics and immune checkpoint inhibitors in the front-line setting. Other important phase II studies have tested molecular therapies directed against different novel targets, such as transforming growth factor-beta, MET (hepatocyte growth factor receptor), and fibroblast growth factor receptor 4. These studies integrated translational research with the aim of better defining the biological tumour profile and identifying tumour and blood biomarkers that select patients who may really benefit from a specific molecular therapy. Importantly, good safety profiles make these drugs suitable for future combinations. In this review, we discuss the most recent data on novel combination strategies and targets, as well as looking ahead to the future role of molecular therapies in the treatment of patients with advanced HCC.

Current Status and Future Direction of Immunotherapy in Hepatocellular Carcinoma: What Do the Data Suggest?

Most patients with hepatocellular carcinoma (HCC) are diagnosed at an advanced stage of disease. Until recently, systemic treatment options that showed survival benefits in HCC have been limited to tyrosine kinase inhibitors, antibodies targeting oncogenic signaling pathways or VEGF receptors. The HCC tumor microenvironment is characterized by a dysfunction of the immune system through multiple mechanisms, including accumulation of various immunosuppressive factors, recruitment of regulatory T cells and myeloid-derived suppressor cells, and induction of T cell exhaustion accompanied with the interaction between immune checkpoint ligands and receptors. Immune checkpoint inhibitors (ICIs) have been interfered this interaction and have altered therapeutic landscape of multiple cancer types including HCC. In this review, we discuss the use of anti-PD-1, anti-PD-L1, and anti-CTLA-4 antibodies in the treatment of advanced HCC. However, ICIs as a single agent do not benefit a significant portion of patients. Therefore, various clinical trials are exploring possible synergistic effects of combinations of different ICIs (anti-PD-1/PD-L1 and anti-CTLA-4 antibodies) or ICIs and target agents. Combinations of ICIs with locoregional therapies may also improve therapeutic responses.

Diagnosis and management of toxicities of immune checkpoint inhibitors in hepatocellular carcinoma

Immune checkpoint inhibitors (ICIs) have reshaped cancer therapy. ICIs enhance T cell activation through various mechanisms and may help reverse the exhausted phenotype of tumour-infiltrating lymphocytes. However, disrupting the key role that checkpoint molecules play in immune homeostasis may result in autoimmune complications. A broad range of immune-related adverse events (irAEs) involve almost every organ but mostly affect the skin, digestive system, lung, endocrine glands, nervous system, kidney, blood cells, and musculoskeletal system. They are usually manageable but can be life-threatening. The incidence of irAEs is not very different in patients with hepatocellular carcinoma (HCC) compared to other tumour types, although there is a trend towards a higher incidence of hepatic irAEs. HCC usually develops on a background of cirrhosis with associated systemic manifestations. Extrahepatic organ dysfunction in cirrhosis may cause signs and symptoms that overlap with irAEs or increase their severity. Available guidelines for the management of irAEs have not specifically considered the assessment of toxicities in the context of patients with liver cancer and cirrhosis. This review addresses the toxicity profile of ICIs in patients with HCC, focusing on the challenges that the underlying liver disease poses to their diagnosis and management. Challenges include late recognition, inadequate work-up and delayed treatment, overdiagnosis and inappropriate interruption of ICIs, complications caused by immunosuppressive therapy, and increased cost. A specific algorithm for the management of hepatic irAEs is provided.

Systemic Therapy for Hepatocellular Carcinoma: Advances and Hopes

The majority of patients with hepatocellular carcinoma (HCC) are diagnosed at an advanced stage that can only benefit from systemic treatments. Although HCC is highly treatmentresistant, significant achievements have been made in the molecular targeted therapy and immunotherapy of HCC. In addition to regorafenib, cabozantinib and ramucirumab were approved for the second- line targeted treatment by the FDA after disease progression on sorafenib. Nivolumab failed to demonstrate remarkable benefit in overall survival (OS) as first-line therapy, while pembrolizumab did not achieve pre-specified statistical significance in both OS and progression-free survival (PFS) as second-line treatment. Combinations of targeted agents, immune checkpoint inhibitors and other interventions showed favorable results. In this review, we summarized the progress of systemic therapy in HCC and discussed the future directions of the treatment of HCC.

Immune Therapy for Liver Cancers

Hepatocellular carcinoma (HCC) and biliary tract cancers (BTC) display a poor prognosis with 5-year overall survival rates around 15%, all stages taken together. These primary liver malignancies are often diagnosed at advanced stages where therapeutic options are limited. Recently, immune therapy has opened new opportunities in oncology. Based on their high programmed death-ligand 1 expression and tumor-infiltrating lymphocytes, HCC and BTC are theoretically good candidates for immune checkpoint blockade. However, clinical activity of single agent immunotherapy appears limited to a subset of patients, which is still ill-defined, and combinations are under investigation. In this review, we provide an overview of (i) the biological rationale for immunotherapies in HCC and BTC, (ii) the current state of their clinical development, and (iii) the predictive value of immune signatures for both clinical outcome and response to these therapies.

Rationale of Immunotherapy in Hepatocellular Carcinoma and Its Potential Biomarkers

Hepatocellular carcinoma (HCC), the most common type of liver cancer, is derived mostly from a background of chronic inflammation. Multiple immunotherapeutic strategies have been evaluated in HCC, with some degree of success, particularly with immune checkpoint blockade (ICB). Despite the initial enthusiasm, treatment benefit is only appreciated in a modest proportion of patients (response rate to single agent ~20%). Therapy-induced immune-related adverse events (irAEs) and economic impact are pertinent considerations with ICB. It is imperative that a deeper understanding of its mechanisms of action either as monotherapy or in combination with other therapeutic agents is needed. We herein discuss the latest developments in the immunotherapeutic approaches for HCC, the potential predictive biomarkers., and the rationale for combination therapies. We also outline promising future immunotherapeutic strategies for HCC patients.

Current strategies for the treatment of intermediate and advanced hepatocellular carcinoma

Hepatocellular carcinoma (HCC) ranks among the most common cancers worldwide and remains to be a major global health care problem. Until 2007, no effective therapies were available for patients after failure of locoregional approaches, and the approval of sorafenib as the first systemic agent with efficacy in patients suffering from advanced HCC marked a new era in the treatment of this deadly disease. However, it took nearly 10 years until the portfolio of effective drugs finally expanded and additional substances showed activity in both first and further lines of treatment. Since their recent approval, these novel substances have substantially changed the field of palliative treatment strategies in patients with advanced HCC, and their sequential application has demonstrated their potential to significantly prolong patient survival in the palliative setting. With the recently communicated data from the first positive immuno-oncology trial in HCC, it appears highly likely that the implementation of IO concepts will result in a further improvement of patient prognosis. Although locoregional approaches remain an integral component of meaningful treatment concepts for patients with BCLC-B stage HCC, repetitive interventions bear the risk of a progressive deterioration of liver function. More than ever, in order to implement long-term therapeutic concepts and exploit the full potential of systemic treatment strategies, it is of utmost importance to maintain a fine balance between anti-tumor activity and toxicity. With an emphasis on the systemic treatment options, this review provides a summary of the most recent results from large phase III clinical trials and discusses their clinical implications.

Therapeutic Monoclonal Antibodies Targeting Immune Checkpoints for the Treatment of Solid Tumors

Recently, modulation of immune checkpoints has risen to prominence as a means to treat a number of solid malignancies, given the durable response seen in many patients and improved side effect profile compared to conventional chemotherapeutic agents. Several classes of immune checkpoint modulators have been developed. Here, we review current monoclonal antibodies directed against immune checkpoints that are employed in practice today. We discuss the history, mechanism, indications, and clinical data for each class of therapies. Furthermore, we review the challenges to durable tumor responses that are seen in some patients and discuss possible interventions to circumvent these barriers.