Immune checkpoint inhibitors in the treatment of hepatocellular carcinoma

Despite advances in cancer treatment, hepatocellular carcinoma (HCC), the most common form of liver cancer, remains a major public health problem worldwide. The immune microenvironment plays a critical role in regulating tumor progression and resistance to therapy, and in HCC, the tumor microenvironment (TME) is characterized by an abundance of immunosuppressive cells and signals that facilitate immune evasion and metastasis. Recently, anti-cancer immunotherapies, therapeutic interventions designed to modulate the immune system to recognize and eliminate cancer, have become an important cornerstone of cancer therapy. Immunotherapy has demonstrated the ability to improve survival and provide durable cancer control in certain groups of HCC patients, while reducing adverse side effects. These findings represent a significant step toward improving cancer treatment outcomes. As demonstrated in clinical trials, the administration of immune checkpoint inhibitors (ICIs), particularly in combination with anti-angiogenic agents and tyrosine kinase inhibitors, has prolonged survival in a subset of patients with HCC, providing an alternative for patients who progress on first-line therapy. In this review, we aimed to provide an overview of HCC and the role of the immune system in its development, and to summarize the findings of clinical trials involving ICIs, either as monotherapies or in combination with other agents in the treatment of the disease. Challenges and considerations regarding the administration of ICIs in the treatment of HCC are also outlined.

Unresectable Hepatocellular Carcinoma: A Review of New Advances with Focus on Targeted Therapy and Immunotherapy

With an expected incidence of more than 1 million cases by 2025, liver cancer remains a problem for world health. With over 90% of cases, hepatocellular carcinoma (HCC) is the most prevalent kind of liver cancer. In this review, we presented the range of experimental therapeutics for patients with advanced HCC, the successes and failures of new treatments, areas for future development, the evaluation of dose-limiting toxicity in different drugs, and the safety profile in patients with liver dysfunction related to the underlying chronic liver disease. In addition to the unmet demand for biomarkers to guide treatment decisions and the burgeoning fields of immunotherapy and systemic therapy in hepatocellular carcinoma, the development of old and new drugs, including their failures and current advancements, has been reviewed. This review aims to evaluate the updated optimal clinical treatment of unresectable hepatocellular carcinomas in clinical practice, mainly through targeted therapy. Although surgical treatment can significantly enhance the survival probability of early and intermediate-stage patients, it is unsuitable for most HCC patients due to a lack of donors. Due to their severe toxicity, the few first-line anti-HCC drugs, such as sorafenib, are often reserved for advanced HCC patients for whom other therapies have failed. The second-line drugs are usually alternatives for patients with intolerance or resistance. Consequently, the ongoing growth of possible preclinical drugs and studies on miRNAs, lncRNAs, and numerous other signaling pathway targets for developing novel drugs may introduce additional treatment prospects for HCC.

Genetic Heterogeneity, Therapeutic Hurdle Confronting Sorafenib and Immune Checkpoint Inhibitors in Hepatocellular Carcinoma

Despite the latest advances in hepatocellular carcinoma (HCC) screening and treatment modalities, HCC is still representing a global burden. Most HCC patients present at later stages to an extent that conventional curative options are ineffective. Hence, systemic therapy represented by the tyrosine kinase inhibitor, sorafenib, in the first-line setting is the main treatment modality for advanced-stage HCC. However, in the two groundbreaking phase III clinical trials, the SHARP and Asia-Pacific trials, sorafenib has demonstrated a modest prolongation of overall survival in almost 30% of HCC patients. As HCC develops in an immune-rich milieu, particular attention has been placed on immune checkpoint inhibitors (ICIs) as a novel therapeutic modality for HCC. Yet, HCC therapy is hampered by the resistance to chemotherapeutic drugs and the subsequent tumor recurrence. HCC is characterized by substantial genomic heterogeneity that has an impact on cellular response to the applied therapy. And hence, this review aims at giving an insight into the therapeutic impact and the different mechanisms of resistance to sorafenib and ICIs as well as, discussing the genomic heterogeneity associated with such mechanisms.

Research Progresses of Targeted Therapy and Immunotherapy for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide, with nearly one million new cases and deaths every year. Owing to the complex pathogenesis, hidden early symptoms, rapidly developing processes, and poor prognosis, the morbidity and mortality of HCC are increasing yearly. With the progress being made in modern medicine, the treatment of HCC is no longer limited to traditional methods. Targeted therapy and immunotherapy have emerged to treat advanced and metastatic HCC in recent years. Since Sorafenib is the first molecular targeting drug against angiogenesis, targeted drugs for HCC are continually emerging. Moreover, immunotherapy plays a vital role in clinical trials. In particular, the application of immune checkpoint inhibitors, which have received increasing attention in the field of cancer treatment, is a possible research path. Interestingly, these two therapies generally complement each other at some stages of HCC, bringing new hope for patients with advanced HCC. In this paper, we discuss the research progress of targeted therapy and immunotherapy for HCC in recent years, which will provide a reference for the further development of drugs for HCC.

Tislelizumab in Chinese patients with advanced solid tumors: an open-label, non-comparative, phase 1/2 study

BACKGROUND

Tislelizumab is an investigational, humanized, IgG4 monoclonal antibody with high affinity and binding specificity for programmed cell death-1 (PD-1) that was engineered to minimize binding to FcγR on macrophages in order to abrogate antibody-dependent phagocytosis, a mechanism of T-cell clearance and potential resistance to anti-PD-1 therapy.

METHODS

The purpose of this phase 1/2, open-label, non-comparative study was to examine the safety, tolerability, and antitumor activity of tislelizumab in adult (≥18 years) Chinese patients with histologically or cytologically confirmed advanced solid tumors with measurable disease. The phase 1 portion of the study consisted of a dose-verification study and a pharmacokinetic (PK) substudy; phase 2 was an indication-expansion study including 11 solid tumor cohorts. Patients previously treated with therapies targeting PD-1 or its ligand, programmed cell death ligand-1 were excluded. During dose-verification, dose-limiting toxicities (DLTs) were monitored; safety and tolerability were examined and the previously determined recommended phase 2 dose (RP2D) was verified. The primary endpoint of phase 2 was investigator-assessed objective response rate per Response Evaluation Criteria in Solid Tumors V.1.1.

RESULTS

As of December 1, 2018, 300 patients were treated with tislelizumab 200 mg intravenously once every 3 weeks (Q3W). Median duration of follow-up was 8.1 months (range 0.2-21.9). No DLTs were reported during the phase 1 dose-verification study and the RP2D was confirmed to be 200 mg intravenously Q3W. Most treatment-related adverse events (62%) were grade 1 or 2, with the most common being anemia (n=70; 23%) and increased aspartate aminotransferase (n=67; 22%). Of the 251 efficacy evaluable patients, 45 (18%) achieved a confirmed clinical response, including one patient from the PK substudy who achieved a complete response. Median duration of response was not reached for all except the nasopharyngeal carcinoma cohort (8.3 months). Antitumor responses were observed in multiple tumor types.

CONCLUSIONS

Tislelizumab was generally well tolerated among Chinese patients. Antitumor activity was observed in patients with multiple solid tumors.

TRIAL REGISTRATION NUMBER

CTR20160872.

The Efficacy and Safety of Programmed Death-1 and Programmed Death Ligand 1 Inhibitors for the Treatment of Hepatocellular Carcinoma: A Systematic Review and Meta-Analysis

BACKGROUND

Hepatocellular carcinoma (HCC) is often diagnosed at an advanced stage where only systemic treatment can be offered. The emergence of immune checkpoint inhibitors (ICIs) provides hope for the treatment of HCC. In this study, we performed a meta-analysis to provide evidence for the efficacy and safety of ICIs in the treatment of HCC.

METHODS

The following databases and websites were searched: Embase, PubMed, Cochrane Library and ClinicalTrials.gov. The primary endpoints were response rate (RR), disease control rate (DCR), progression-free survival (PFS) and overall survival (OS).

RESULTS

Finally, twelve studies were included in this meta-analysis. When the corresponding outcome indicators and their 95% confidence intervals (CIs) were pooled directly, the overall RR, DCR, PFS and OS were 0.17 (0.15-0.19, I2 = 56.2%, P=0.009), 0.58 (0.55-0.61, I2 = 75.9%, P<0.001), 3.27 months (2.99-3.55, I2 = 73.0%, P=0.001), 11.73 months (10.79-12.67, I2 = 90.3%, P<0.001). Compared to the control group, treatment with ICIs significantly improved RR, PFS and OS, the OR and HRs were 3.11 (2.17-4.44, P<0.001), 0.852 (0.745-0.974, P=0.019) and 0.790 (0.685-0.911, P=0.001), respectively. However, no significant improvement in DCR was found in ICIs treatment in this meta-analysis.

CONCLUSION

HCC patients would benefit from ICIs treatment, however, more studies are needed in the future to provide more useful evidence for the treatment of HCC by programmed death-1 (PD-1) or programmed death ligand 1 (PD-L1) inhibitors.

Recent Advances in Systemic Therapies for Advanced Hepatocellular Carcinoma

Purpose of Review

This paper aims to summarize the data of recently completed and key ongoing clinical trials of systemic agents for advanced hepatocellular carcinoma (aHCC). In particular, the review focuses on ongoing checkpoint inhibitor combination trials and promising studies combining tyrosine kinase inhibitors with checkpoint inhibitors.

Recent Findings

The recently approved combination of atezolizumab and bevacizumab based on the IMbrave150 trial has shown the most potential with the highest overall survival of any systemic agent in HCC to date, surpassing sorafenib. Despite COVID-19 delays, other promising trials that involve combining VEGF-directed therapy and checkpoint inhibition, cancer vaccines, phosphatidylserine, YIV-906, and oncolytic and immunotherapeutic vaccinia virus are actively recruiting patients.

Summary

After almost a 10-year dormancy, the list of potential systemic treatment options for aHCC is growing rapidly. Given the promising data from the IMbrave150 trial, the combination of atezolizumab and bevacizumab is now the new first-line therapy. We discuss the change in landscape, the new second- and third-line systemic treatments in aHCC, and the ongoing clinical trials for newer agents including combination therapies.

The Growing Skyline of Advanced Hepatocellular Carcinoma Treatment: A Review

Hepatocellular carcinoma (HCC) is the main type of liver cancer. In the majority of cases, HCC is diagnosed at the advanced stage, leading to poor prognosis. In recent years, many efforts have been devoted to investigating potential new and more effective drugs and, indeed, the treatment armamentarium for advanced HCC has broadened tremendously, with targeted- and immune-therapies, and probably the combination of both, playing pivotal roles. Together with new established knowledge, many issues are emerging, with the role of neoadjuvant/adjuvant settings, the definition of the best transitioning time from loco-regional treatments to systemic therapy, the identification of potential predictive biomarkers, and radiomics being just some of the topics that will have to be further explored in the next future. Clearly, the current COVID-19 pandemic has influenced the management of HCC patients and some considerations about this topic will be elucidated.

Tislelizumab: First Approval

Tislelizumab (^®;; Tileilizhu Dankang Zhusheye) is an anti-human programmed death receptor-1 (PD-1) monoclonal IgG4 antibody that is being developed by BeiGene as an immunotherapeutic, anti-neoplastic drug. Tislelizumab has been investigated in haematological cancers and advanced solid tumours, leading to its approval in December 2019 in China for patients with relapsed or refractory classical Hodgkin's lymphoma after at least second-line chemotherapy. This article summarises the major milestones in the development of tislelizumab for this first approval for classical Hodgkin's lymphoma, and its potential upcoming approvals in other indications.

Immune Checkpoint Inhibitors in Hepatocellular Carcinoma: An Overview

Patients with hepatocellular carcinoma (HCC) face a common type of cancer, which is amongst the most deadly types of cancer worldwide. The therapeutic options range from curative resection or ablation to loco regional therapies in palliative setting and last but not least, systemic treatment. The latter group underwent major changes in the last decade and a half. Since the introduction of sorafenib in 2007, many other systemic treatments have been investigated. Most without success. It took more than ten years before lenvatinib could be added as alternative first-line treatment option. Just recently a new form of systemic treatment, immunotherapy, entered the field of therapeutic options in patients with HCC. Immune checkpoint inhibitors are becoming the new standard of care in patients with HCC. Several reviews reported on the latest phase 1/2 studies and discussed the higher response rates and better tolerability when compared to current standard of care therapies. This review will focus on elaborating the working mechanism of these checkpoint inhibitors, give an elaborate update of the therapeutic agents that are currently available or under research, and will give an overview of the latest trials, as well as ongoing and upcoming trials.

Case Report: Double Germline Mutations in BRCA1 and MSH2 in a Patient With Mixed Serous-Endometrioid Endometrial Carcinoma

Mixed serous-endometrioid endometrial carcinoma is a type of endometrial cancer with relatively low incidence. The genetic factors contributing to the tumorigenesis of mixed carcinoma remains to be explored. Here, we report the first identification of two germline mutations in BRCA1 and MSH2 in a woman with mixed serous papillary adenocarcinoma and endometrioid carcinoma. Immunohistochemistry analysis showed loss of MSH2 and MSH6 protein expression in the endometrioid component. The patient showed partial response to tislelizumab treatment following progression on chemotherapy. Two germline mutations in BRCA1 and MSH2 may collectively promote the tumorigenesis of uterine endometrium with two distinct histological components.

Immune Checkpoint Inhibitors in Hepatocellular Carcinoma: Current Status and Novel Perspectives

Immune checkpoint inhibitors (ICIs) represent a promising treatment for many kinds of cancers, including hepatocellular carcinoma (HCC). The rationale for using ICIs in HCC is based on the immunogenic background of hepatitis and cirrhosis and on the observation of high programmed death-ligand 1 (PD-L1) expression and tumor-infiltrating lymphocytes in this cancer. Promising data from phase I/II studies in advanced HCC, showing durable objective response rates (~20% in first- and second-line settings) and good safety profile, have led to phase III studies with ICIs as single agents or in combination therapy, both in first and second line setting. While the activity of immunotherapy agents as single agents seems to be limited to an "ill-defined" small subset of patients, the combination of the anti PD-L1 atezolizumab and anti-vascular endothelial growth factor bevacizumab revealed a benefit in the outcomes when compared to sorafenib in the first line. In addition, the activity and efficacy of the combinations between anti-PD-1/anti-PD-L1 antibody and other ICIs, tyrosine kinase inhibitors, or surgical and locoregional therapies, has also been investigated in clinical trials. In this review, we provide an overview of the role of ICIs in the management of HCC with a critical evaluation of the current status and future directions.

Immune Checkpoint Inhibitors as Monotherapy or Within a Combinatorial Strategy in Advanced Hepatocellular Carcinoma

In advanced-stage hepatocellular carcinoma (HCC), systemic treatment represents the standard therapy. Target therapy has marked a new era based on a greater knowledge of molecular disease signaling. Nonetheless, survival outcomes and long-term response remain unsatisfactory, mostly because of the onset of primary or acquired resistance. More recently, results from clinical trials with immune targeting agents, such as the immune checkpoint inhibitors (ICIs), have shown a promising role for these drugs in the treatment of advanced HCC. In the context of an intrinsic tolerogenic liver environment, since HCC-induced immune tolerance, it is supported by multiple immunosuppressive mechanisms and several clinical trials are now underway to evaluate ICI-based combinations, including their associations with antiangiogenic agents or multikinase kinase inhibitors and multiple ICIs combinations. In this review, we will first discuss the basic principles of hepatic immunogenic tolerance and the evasive mechanism of antitumor immunity in HCC; furthermore we will elucidate the consistent biological rationale for immunotherapy in HCC even in the presence of an intrinsic tolerogenic environment. Subsequently, we will critically report and discuss current literature on ICIs in the treatment of advanced HCC, including a focus on the currently explored combinatorial strategies and their rationales. Finally, we will consider both challenges and future directions in this field.

Therapy of Primary Liver Cancer

Primary liver cancer (PLC) is a fatal disease that affects millions of lives worldwide. PLC is the leading cause of cancer-related deaths and the incidence rate is predicted to rise in the coming decades. PLC can be categorized into three major histological subtypes: hepatocellular carcinoma (HCC), intrahepatic cholangiocarcinoma (ICC), and combined HCC-ICC. These subtypes are distinct with respect to epidemiology, clinicopathological features, genetic alterations, and clinical managements, which are thoroughly summarized in this review. The state of treatment strategies for each subtype, including the currently approved drugs and the potential novel therapies, are also discussed.