Immune-based combinations for advanced hepatocellular carcinoma: shaping the direction of first-line therapy

Case Report: Complete Response of Primary Massive Hepatocellular Carcinoma to Anti-Programmed Death Ligand-1 Antibody Following Progression on Anti-Programmed Death-1 Antibody

Hepatocellular carcinoma (HCC) is an aggressive liver tumor that occurs due to chronic liver disease, and it has a high mortality rate and limited treatment options. Immune checkpoint inhibitors have been successfully introduced and used in cancer therapy, among which inhibitors of programmed death ligand-1 (PD-L1) and its receptor programmed death-1 (PD-1) are commonly administered for HCC as combination therapy, including combined anti-angiogenic and immunotherapy combination therapy. We report a case of a primary massive HCC patient with portal hepatic vein tumor thrombus who had a good response to atezolizumab in combination with bevacizumab, following progression of disease on combined immunotherapy with pembrolizumab and lenvatinib. This case demonstrates for the first time that an HCC patient who is resistant to anti-PD-1 antibody immunotherapy can benefit from anti-PD-L1 antibody immunotherapy, providing a potentially promising strategy for the treatment of HCC.

An Overview of the Genomic Characterization of Hepatocellular Carcinoma

Tumor classifications based on alterations in the genome, epigenome, or proteome have revealed distinct tumor subgroups that are associated with clinical outcomes. Several landmark studies have demonstrated that such classifications can significantly improve patient outcomes by enabling tailoring of therapy to specific alterations in cancer cells. Since cancer cells accumulate numerous alterations in many cancer-related genes, it is a daunting task to find and confirm important cancer-promoting alterations as therapeutic targets or biomarkers that can predict clinical outcomes such as survival and response to treatments. To aid further advances, we provide here an overview of the current understanding of molecular and genomic subtypes of hepatocellular carcinoma (HCC). System-level integration of data from multiple studies and development of new technical platforms for analyzing patient samples hold great promise for the discovery of new targets for treatment and correlated biomarkers, leading to personalized medicine for treatment of HCC patients.

PD-L1, TMB, and other potential predictors of response to immunotherapy for hepatocellular carcinoma: how can they assist drug clinical trials?

INTRODUCTION

Hepatocellular carcinoma (HCC) represents the sixth most commonly diagnosed malignancy worldwide, accounting for millions of deaths annually. Despite immune checkpoint inhibitors (ICIs) reported important results, only a minority of HCC patients benefit from these treatments, and the identification of predictive biomarkers of response still remains a highly unmet need.

AREAS COVERED

Herein, we provide a timely overview of available evidence on biochemical predictors of response to immunotherapy in advanced HCC patients; we speculate on how PD-L1, TMB, and other emerging biomarkers could assist drug clinical trials in the near future. A literature search was conducted in June 2021 using Pubmed/Medline, Cochrane library, and Scopus databases.

EXPERT OPINION

Reliable predictors of response to ICIs are of pivotal importance to allow a proper stratification and selection of HCC patients that could derive more benefit from immunotherapy. Well-designed, multicenter clinical trials specifically focused on predictive biomarkers are warranted in this setting, where most of evidence currently derives from retrospective, single-center studies with small sample size.

Patient preferences for advanced hepatocellular carcinoma treatment: a multicountry stated preference study

The present study aimed to explore patient preferences for attributes of advanced hepatocellular carcinoma (HCC) treatments. A stated preference survey was completed by 150 patients with HCC living in Europe. Overall survival (OS) was the most important attribute, closely followed by risk of diarrhea and hypertension, and other adverse event (AE) risks. Patients were willing to trade OS to reduce AE risks. While less important than OS and AEs, patients also preferred shorter waiting times, and one-off administration of selective internal radiation therapy and oral tablets over intravenous infusions. Although patients placed the most value on extending OS, they were willing to forego OS to avoid risk of treatment-related AEs, to maintain their quality of life.

An Exploratory Study for the Association of Gut Microbiome with Efficacy of Immune Checkpoint Inhibitor in Patients with Hepatocellular Carcinoma

Background

Gut microbiome has been associated with the efficacy of immune checkpoint inhibitors (ICI) in patients with various types of cancers but not yet in hepatocellular carcinoma (HCC).

Aims

To investigate the association between gut microbiome and efficacy of ICI in patients with HCC.

Methods

Patients with HCC who were scheduled to receive ICI were prospectively enrolled. Fecal samples were collected within 7 days before initiation of ICI (baseline) and 8 weeks later. Gut microbiome was assessed using 16S rRNA sequencing and shotgun whole-genome sequencing and correlated with objective response (complete or partial response), disease control (objective response or stable disease for ≥16 weeks), and overall survival.

Results

Thirty-six patients with HCC were enrolled, and 20 of them provided both baseline and 8-week feces. Alpha diversity, richness, and compositions of baseline gut microbiome indicated no difference between responders and nonresponders or between disease control and nondisease control groups. For the 20 paired feces, immunotherapy did not change any of the major microbiome features. No specific taxa were enriched in patients with objective response. Three taxa-Bifidobacterium, Coprococcus, and Acidaminococcus-were enriched in patients with disease control. However, the baseline abundance of these three taxa did not predict overall survival benefit.

Conclusions

In this exploratory study, we failed to disclose any overt association of gut microbiome with the efficacy of ICI in patients with HCC. A larger prospective study is warranted for definite conclusion.

The efficacy of immune checkpoint inhibitors in advanced hepatocellular carcinoma: a meta-analysis based on 40 cohorts incorporating 3697 individuals

BACKGROUND

This study was designed to investigate the efficacy and safety of immune checkpoint inhibitors (ICIs) in advanced hepatocellular carcinoma (HCC).

METHODS

Electronic databases were scanned to identify relevant trials. The primary endpoints were overall survival (OS), progression-free survival (PFS), and their prognostic factors. Stratified analyses were accomplished on ICIs agent and evaluation criteria.

RESULTS

Totally, 3697 individuals from 40 cohorts were recruited. For patients treated with ICIs, the pooled median time to progression (TTP) was 8.0 months, median PFS 4.9 months, and median OS 12.0 months; the pooled median PFS and OS of ICIs plus anti-vascular endothelial growth factor (VEGF) agents (PFS: 6.3 months, OS: 16.4 months) were longer than those of ICIs alone. Furthermore, Child-Pugh stage (HR = 1.37, P = 0.0123) and Eastern Cooperative Oncology Group (ECOG) (HR = 1.40, P = 0.0016) were prognostic factors for PFS. Hepatitis C virus (HCV) (HR = 0.71, P = 0.0356), Alpha-fetoprotein (AFP) (HR = 1.17, P < 0.0001), Child-Pugh stage (HR = 1.58, P < 0.0001), Barcelona Clinic Liver Cancer (BCLC) stage (HR = 1.23, P = 0.0005), ECOG (HR = 1.50, P = 0.0012), portal vein invasion (HR = 1.32, P = 0.0053), extrahepatic metastasis (HR = 0.84, P = 0.0047), best response (HR = 0.58, P < 0.0001), and neutrophil-to-lymphocyte ratio (NLR) (HR = 1.23, P = 0.0451) were the prognostic factors for OS. According to both RECIST 1.1 and mRECIST, the objective response rate (ORR) and disease control rate (DCR) rate of ICIs plus anti-VEGF agents were better than those of ICIs alone. The overall rate of any grade adverse events (AEs) was 0.76 (95% CI 0.61-0.89), grade 3 or higher AEs was 0.28 (95% CI 0.15-0.42), and the rate of AEs leading to treatment discontinuation was 0.09 (95% CI 0.06-0.12).

CONCLUSIONS

The ICIs was promising in HCC with good efficacy and tolerated toxicity. Compared with ICIs monotherapy, the joint application of ICIs and anti-VEGF agents can contribute a lot more benefits to the survival of patients according to clinical practices.

Evolving therapeutic strategies for advanced hepatocellular carcinoma

Introduction: While sorafenib dominated the therapeutic arena in advanced hepatocellular carcinoma (HCC) for almost a decade, newer agents and combinations have been changing the therapeutic landscape in the last years.Areas covered: The authors outline the etiopathogenesis and evaluate the diagnostics in HCC, followed by a comprehensive review of the currently approved and experimental treatment approaches, with a focus on various systemic agents and combinations of agents. The manuscript was subdivided into relevant categories, thus making it applicable for both clinical practice and research endeavors.Expert opinion: Recently, combination therapies including immune checkpoint inhibitors with anti-VEGF/R agents have shown superior clinical efficacy in HCC. The Atezolizumab-bevacizumab combination is currently the preferred first-line therapy. Single-agents cabozantinib and regorafenib as well as nivolumab-ipilimumab combination are favored as second-line therapies. Further research is needed to identify the predictors of response to various treatments and establish the distinct patient profiles that will derive most benefit. Tumor mutation analysis and germline mutation testing could identify rational therapeutic targets in HCC in the near future. As the skyline for new therapeutic agents and combinations in HCC continues to expand, the outlook as of today is cautiously optimistic in this still difficult-to-treat malignant neoplastic disease.

Multi-omic analyses of hepatocellular carcinoma to determine immunological characteristics and key nodes in gene-expression network

Hepatocellular carcinoma (HCC) is a common malignant tumor worldwide, but effective immunotherapy is still limited for those affected. Therefore, there is an urgent need to explore the specific mechanisms governing tumor immunity to improve the survival rate for those diagnosed with HCC. In the present study, we performed a new immune stratification of HCC samples into two subclasses (A and B) from The Cancer Genome Atlas and the International Cancer Genome Consortium databases, and comprehensive multi-omic analyses of major histocompatibility complex genes, gene copy-number variations, somatic mutations, DNA methylation, and non-coding RNAs. Subclass A was found to have a higher survival rate compared with subclass B, and there were significant immunological differences between the two clusters. Based on these differences, we identified DRD1 and MYCN as key hub genes in the immune-phenotype gene expression regulatory network. These results provide novel ideas and evidence for HCC regulatory mechanisms that may improve immunotherapy for this cancer.

Lenvatinib plus pembrolizumab: the next frontier for the treatment of hepatocellular carcinoma?

Introduction: While sorafenib monotherapy represented the mainstay of medical treatment for advanced hepatocellular carcinoma (HCC) patients for more than a decade, novel agents and combination therapies have recently produced unprecedented paradigm shifts. The combination of lenvatinib plus pembrolizumab is now being evaluated as a front-line treatment in advanced HCC patients; early phase clinical trials have already reported promising results.Areas covered: This paper reviews the combination of lenvatinib plus pembrolizumab for the treatment of advanced HCC. The preclinical rationale and completed and ongoing trials are examined and later, the authors reflect on biomarkers of predictive of response to immune-based combinations and future treatment decision-making on the basis of tolerability and clinical benefits provided by these novel therapeutics. A literature search was conducted in April 2021 of Pubmed/Medline, Cochrane library and Scopus databases; moreover, abstracts of international cancer meetings were reviewed.Expert opinion: The landscape of new agents and combinations continues to expand. Recently, immune-based combinations have reported important results in advanced HCC, as witnessed by the landmark IMbrave150 trial. Based on the promising results of early phase clinical trials, lenvatinib plus pembrolizumab has the potential to represent a novel treatment option in this setting.

Obatoclax, the pan-Bcl-2 inhibitor sensitizes hepatocellular carcinoma cells to promote the anti-tumor efficacy in combination with immune checkpoint blockade

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Obatoclax, the Bcl-2 inhibitor directly impaired HCC cell growth.

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Obatoclax suppressed HCC development in vivo.

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Obatoclax sensitized HCC cells to T cell-mediated killing.

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Combination therapy of obatoclax and anti-PD-1 antibody synergically reduced HCC growth.

Bcl-2 family proteins play critical roles in regulating lymphocyte development and maintain homeostasis, and have also been proved to be involved in various cancer types development. However, the role of Bcl-2 in hepatocellular carcinoma (HCC) development has not been clearly studied. Here, we reported the pan-Bcl-2 inhibitor, obatoclax could directly inhibit HCC growth in vitro. We further demonstrated in murine HCC model that obatoclax also suppressed HCC development in vivo. We also proved that although obatoclax inhibited T cells expansion, it had no influence on T cells activation in vivo. Mechanism study revealed that obatoclax sensitized HCC cells to T cell-mediated killing. Combination therapy of obatoclax with anti-PD-1 antibody synergistically suppressed HCC development and prolonged the survival rate of tumor-bearing mice. The combination therapy promoted T cells activation and effector cytokines expression both in spleen and tumor. In summary, our results proved that obatoclax sensitized HCC cells to T cell -mediated killing. Combination of obatoclax with immune checkpoint blockade served as a promising therapeutic strategy for HCC treatment.

Atezolizumab in advanced hepatocellular carcinoma: good things come to those who wait

Advanced hepatocellular carcinoma (HCC) patients present poor prognosis. However, recent years have seen the advent of several novel treatments in this setting, where the role of immune checkpoint inhibitors has been investigated. Among these, the PD-L1 inhibitor atezolizumab in combination with bevacizumab has reported unprecedented results in treatment-naive patients with unresectable disease, with the recently published IMbrave150 Phase III trial showing the superiority of the combination over sorafenib monotherapy, and after having attended more than a decade of 'stagnation', the HCC medical community has a new standard of care. Herein, we examine the development and the impact of atezolizumab in advanced HCC, summarizing the mechanism of action, pharmacokinetics and recent evidence from Phase I to III clinical trials.

Durvalumab: an investigational anti-PD-L1 antibody for the treatment of biliary tract cancer

Introduction: The prognosis of patients with advanced biliary tract cancer (BTC) remains dismal, with a 5-year overall survival rate of less than 10%. Although immune checkpoint inhibitors (ICIs) have revolutionized the treatment landscape of several hematological and solid tumors, controversial results have been reported in BTC. In this setting, the anti-PD-L1 inhibitor durvalumab is currently under investigation in several clinical trials as monotherapy, or in combination with other pharmacological agents.Areas covered: We offer an overview of immunotherapies for BTC, discuss recently published or presented data on durvalumab pharmacology, safety, and efficacy in the treatment of BTC and consider future research directions for the agent in this setting.Expert opinion: The promising antitumor activity shown by durvalumab in early trials warrants further investigation because it may provide more effective, much needed treatment options. The results of clinical trials of this PD-L1 inhibitor, as a monotherapy or in combination, are eagerly awaited. Future efforts should focus on the identification and development of reliable biomarkers of response to durvalumab in BTC, clarifying the role of PD-L1 expression, microsatellite instability (MSI), mismatch repair (MMR), tumor mutational burden (TMB) and other emerging predictors.

First-line Chemotherapy in Advanced Biliary Tract Cancer Ten Years After the ABC-02 Trial: "And Yet It Moves!"

Biliary tract cancers (BTCs) include a heterogeneous group of highly aggressive hepatobiliary malignancies, representing the 3% of all gastrointestinal cancers and the second most frequent type of primary liver cancer after hepatocellular carcinoma. Ten years after the publication of the phase III, randomized, ABC-02 trial, the combination of cisplatin plus gemcitabine remains the standard first-line treatment for patients with advanced BTC. In the last decade, a large number of attempts has been made to improve the efficacy of the reference doublet by using novel drugs or adding a third agent to cisplatin-gemcitabine. Unfortunately, despite the addition of different cytotoxic drugs failed to improve clinical outcomes in several studies, recently published clinical trials have provided interesting results, and other first-line chemotherapy options are currently under investigation in randomized phase III studies. Moreover, recent years have witnessed the parallel emergence of molecularly targeted therapies and immune checkpoint inhibitors, with these novel agents having the potential to revolutionize the therapeutic algorithm of advanced BTC. In this review, we will provide an overview on first-line therapeutic opportunities currently available in the management of advanced BTCs, especially focusing on recently published data and ongoing clinical trials in this setting.