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

Changing the Treatment Paradigm for Hepatocellular Carcinoma Using Atezolizumab plus Bevacizumab Combination Therapy

Atezolizumab plus bevacizumab combination therapy was approved worldwide for use in 2020. A 30% objective response rate with 8% complete response (CR) was achieved in a phase 3 IMbrave150 trial. Here, the change in the treatment strategy for hepatocellular carcinoma (HCC) using atezolizumab plus bevacizumab combination therapy is reviewed. The phase 3 IMbrave150 clinical trial was successful because of the direct antitumor effect of bevacizumab, which shifted the suppressive immune microenvironment to a responsive immune microenvironment, in addition to its synergistic effects when combined with atezolizumab. The analysis of CR cases was effective in patients with poor conditions, particularly tumor invasion in the main portal trunk (Vp4), making the combination therapy a breakthrough for HCC treatment. The response rate of the combination therapy was 44% against intermediate-stage HCC. Such a strong tumor-reduction effect paves the way for curative conversion (ABC conversion) therapy and, therefore, treatment strategies for intermediate-stage HCC may undergo a significant shift in the future. As these treatment strategies are effective in maintaining liver function, even in elderly patients, the transition frequency to second-line treatments could also be improved. These strategies may be effective against nonalcoholic steatohepatitis-related hepatocellular carcinoma and WNT/β-catenin mutations to a certain degree.

Thermal ablation and immunotherapy for hepatocellular carcinoma: Recent advances and future directions

Hepatocellular carcinoma (HCC) is one of most common cancers that cause death in the world. Thermal ablation (TA) is an important alternative treatment method for HCC patients who are not appropriate for surgery or liver transplantation. Particularly for small and early HCCs, TA can be considered as the first-line curative treatment. However, local and distant recurrence rates are still high even though the TA equipment and technology develop rapidly. Immunotherapy is a novel systemic treatment method to enhance the anti-tumor immune response of HCC patients, which has the potential to reduce the tumor recurrence and metastasis. The combination of local TA and systemic immunotherapy for HCCs may be an ideal treatment for enhancing the efficacy of TA and controlling the recurrence. Herein we summarize the latest progress in TA, immunotherapy, and their combination for the treatment of patients with HCC and discuss the limitations and future research directions of the combined therapy.

IMpower150 Final Exploratory Analyses for Atezolizumab Plus Bevacizumab and Chemotherapy in Key NSCLC Patient Subgroups With EGFR Mutations or Metastases in the Liver or Brain

INTRODUCTION

Final overall survival (OS) analyses are presented for EGFR mutations and liver or brain metastases subgroups in the phase III IMpower150 study (NCT02366143) evaluating atezolizumab+bevacizumab+carboplatin/paclitaxel (ABCP) or atezolizumab+carboplatin/paclitaxel (ACP) vs bevacizumab+carboplatin/paclitaxel (BCP).

METHODS

Overall, 1202 patients (intention-to-treat [ITT] population) with chemotherapy-naive, metastatic, nonsquamous non-small cell lung cancer were randomized to ABCP, ACP or BCP. Patients with treated, stable brain metastases were permitted. OS was assessed in EGFR mutations and baseline liver metastases subgroups; rate and time to development (TTD) of new brain metastases was assessed in ITT patients.

RESULTS

At data cutoff (September 13, 2019; median follow-up, 39.3 months), OS improvements were sustained with ABCP versus BCP in sensitizing EGFR mutations (all: hazard ratio [HR] 0.60; 95% CI: 0.31-1.14; prior tyrosine kinase inhibitor [TKI]: HR 0.74; 95% CI: 0.38-1.46) and baseline liver metastases (HR 0.68; 95% CI: 0.45-1.02) subgroups. ACP did not show survival benefit versus BCP in sensitizing EGFR mutations (all: HR 1.0; 95% CI: 0.57-1.74; prior TKI: HR 1.22; 95% CI: 0.68-2.22) or liver metastases (HR 1.01; 95% CI: 0.68-1.51) subgroups. Overall, 100 patients (8.3%) developed new brain metastases. While not formally evaluated, an improvement toward delayed TTD was seen with ABCP vs BCP (HR, 0.68; 95% CI: 0.39-1.19).

CONCLUSIONS

This final exploratory analysis showed OS benefits for ABCP versus BCP in patients with sensitizing EGFR mutations, including those with prior TKI failures, and with liver metastases, although these results should be interpreted with caution. The impact of ABCP on delaying the development of new brain lesions requires further investigation.

Unexpected Favorable Outcome to PD-1 Antibody Plus Lenvatinib in a Patient With Recurrent Intestinal Follicular Dendritic Cell Sarcoma: A Case Report and Literature Review

Background

Follicular dendritic cell sarcoma (FDCS) is an uncommon malignant cancer, and there is no standard treatment to date. Resection followed by adjuvant chemotherapy or radiation is considered the most commonly used strategy for treatment. However, the treatment for patients who have progressed after systemic treatment is more controversial.

Case summary

In this case report, we describe a 57-year-old man with primary small intestine FDCS where surgery and second-line systemic chemotherapy failed. After disease progression (PD), the patient received sintilimab plus lenvatinib as third-line treatment and achieved a progression-free survival (PFS) with 7 months.

Conclusion

This is the first report of a FDCS patient treated with immune checkpoint inhibitors (ICIs) and antiangiogenic agents, sintilimab and lenvatinib, as third-line therapy. Our case provides a potential therapeutic option for patients with FDCS who progressed after multiline therapy.

Could Camrelizumab Plus Chemotherapy Improve Clinical Outcomes in Advanced Malignancy? A Systematic Review and Network Meta-Analysis

Purpose

Camrelizumab is a novel programmed cell death 1 (PD-1) inhibitor. To determine the efficacy and safety of the combination treatment of camrelizumab+chemotherapy and camrelizumab monotherapy, and determine which is the most suitable malignancy type to be treated with camrelizumab, we performed a systematic review and network meta-analysis.

Methods

We searched PubMed, Embase, and the Cochrane Library for published clinical trials from database inception until April 2021. Studies that compared camrelizumab+chemotherapy and camrelizumab monotherapy in patients with advanced malignancy were included. We estimated odds ratios (ORs) with credible intervals (CIs) using network meta-analysis with random effects.

Results

We included four clinical trials with 946 advanced malignancy patients. In terms of the efficacy evaluation of the objective response rate and progression-free survival, camrelizumab treatment for Hodgkin lymphoma (HL), camrelizumab treatment for esophageal squamous cell carcinoma (OSCC), and camrelizumab+chemo treatment for HL always ranked first. In terms of safety evaluation from leukocytopenia, hypothyroidism, and asthenia, camrelizumab treatment for OSCC and chemo always ranked first. This study was registered with PROSPERO, number CRD42021249193.

Conclusions

Patients with advanced OSCC should be treated with camrelizumab. Patients with severely relapsed/refractory HL could use camrelizuma+chemo for combination treatment when they can tolerate adverse reactions.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=249193, PROSPERO (identifier, CRD42021249193).

Neoadjuvant Cabozantinib and Nivolumab Converts Locally Advanced HCC into Resectable Disease with Enhanced Antitumor Immunity

A potentially curative hepatic resection is the optimal treatment for hepatocellular carcinoma (HCC), but most patients are not candidates for resection and most resected HCCs eventually recur. Until recently, neoadjuvant systemic therapy for HCC has been limited by a lack of effective systemic agents. Here, in a single arm phase 1b study, we evaluated the feasibility of neoadjuvant cabozantinib and nivolumab in patients with HCC including patients outside of traditional resection criteria (NCT03299946). Of 15 patients enrolled, 12 (80%) underwent successful margin negative resection, and 5/12 (42%) patients had major pathologic responses. In-depth biospecimen profiling demonstrated an enrichment in T effector cells, as well as tertiary lymphoid structures, CD138+ plasma cells, and a distinct spatial arrangement of B cells in responders as compared to non-responders, indicating an orchestrated B-cell contribution to antitumor immunity in HCC.

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.

The impact of atezolizumab and bevacizumab in hepatocellular carcinoma with activated ß-catenin signaling

BACKGROUND

To date, no biomarkers exist to predict response or resistance to immunotherapy in hepatocellular carcinoma (HCC). Recent approaches to classify HCC into different immunological states revealed a negative correlation between Wnt/ß-catenin activation and immunogenicity and T-cell infiltration. If these "cold" tumors with primary resistance to checkpoint inhibition (CPI) may benefit from dual treatment of CPI and anti-angiogenic therapy has not been proved.

CASE

Here, we describe the case of a male patient with metastatic HCC. After failure of standard of care treatment with lenvatinib, sorafenib and ramucirumab fourth-line systemic therapy with atezolizumab and bevacizumab were applied leading to a phenomenal response. Immunohistochemical evaluations were compatible with Wnt/ß-catenin pathway activation and accompanying low T-cell infiltration as well as low PD-L1 score.

CONCLUSION

Patients with Wnt/ß-catenin activation may benefit from combination therapy with atezolizumab and bevacizumab regardless of potential predictive markers for immune checkpoint inhibition.

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.

Favorable response to second-line atezolizumab and bevacizumab following progression on nivolumab in advanced hepatocellular carcinoma: A case report demonstrating that anti-VEGF therapy overcomes resistance to checkpoint inhibition

RATIONALE

Advanced hepatocellular carcinoma (HCC) remains a deadly disease in part due to decades of limited therapeutic options. With recent advances in our understanding of the tumor biology, several promising treatment strategies involving targeted and immunotherapies have emerged. However, enhancing their modest efficacy in HCC and other gastrointestinal malignancies is essential to improving survival.

PATIENT CONCERNS

A man in his late 50s with a history of type 2 diabetes mellitus and morbid obesity initially presented with progressive abdominal pain and anorexia prompting an abdominal computed tomography scan that revealed a large solitary liver mass with extensive local involvement.

DIAGNOSES

Although there were features consistent with a primary gastric tumor on subsequent endoscopic evaluation leading to early diagnostic uncertainty, his clinical picture, including a dominant liver mass, immunohistochemical staining profile, and significantly elevated alpha fetoprotein ultimately favored HCC.

INTERVENTIONS

The patient received palliative systemic therapy with infusional fluorouracil for a presumed gastric primary, however restaging scans after 3 cycles demonstrated disease progression. The consensus from a multidisciplinary discussion was that his pathology was more consistent with primary HCC. He was subsequently started on nivolumab with a partial response, although after 5 months, he progressed prompting initiation of second-line atezolizumab and bevacizumab with a favorable response.

OUTCOMES

The addition of atezolizumab and bevacizumab led to a sustained biochemical and radiographic response that appeared to overcome the resistance to nivolumab monotherapy. Aside from several mild immune-related adverse effects, his quality of life has greatly improved and he has tolerated treatment well to date.

LESSONS

Our findings suggest that vascular endothelial growth factor inhibition can overcome resistance to checkpoint inhibition in advanced HCC by resulting in a unique synergy that has never before been described in patients. The biological rationale for this response is likely attributable to the immunomodulatory effects of antiangiogenic agents, promoting an immunostimulatory microenvironment that can be exploited by immune checkpoint inhibitors for more effective antitumor activity. Given the considerable benefit patients may derive following progression on first-line treatment, it is important to consider this strategic combination of therapies which can ultimately lead to improved patient outcomes.

The Combination of Immune Checkpoint Blockade and Angiogenesis Inhibitors in the Treatment of Advanced Non-Small Cell Lung Cancer

Immune checkpoint blockade (ICB) has become a standard treatment for non-small cell lung cancer (NSCLC). However, most patients with NSCLC do not benefit from these treatments. Abnormal vasculature is a hallmark of solid tumors and is involved in tumor immune escape. These abnormalities stem from the increase in the expression of pro-angiogenic factors, which is involved in the regulation of the function and migration of immune cells. Anti-angiogenic agents can normalize blood vessels, and thus transforming the tumor microenvironment from immunosuppressive to immune-supportive by increasing the infiltration and activation of immune cells. Therefore, the combination of immunotherapy with anti-angiogenesis is a promising strategy for cancer treatment. Here, we outline the current understanding of the mechanisms of vascular endothelial growth factor/vascular endothelial growth factor receptor (VEGF/VEGFR) signaling in tumor immune escape and progression, and summarize the preclinical studies and current clinical data of the combination of ICB and anti-angiogenic drugs in the treatment of advanced NSCLC.

Tumor Immune Microenvironment and Immunosuppressive Therapy in Hepatocellular Carcinoma: A Review

Liver cancer has the fourth highest mortality rate of all cancers worldwide, with hepatocellular carcinoma (HCC) being the most prevalent subtype. Despite great advances in systemic therapy, such as molecular-targeted agents, HCC has one of the worst prognoses due to drug resistance and frequent recurrence and metastasis. Recently, new therapeutic strategies such as cancer immunosuppressive therapy have prolonged patients' lives, and the combination of an immune checkpoint inhibitor (ICI) and VEGF inhibitor is now positioned as the first-line therapy for advanced HCC. Since the efficacy of ICIs depends on the tumor immune microenvironment, it is necessary to elucidate the immune environment of HCC to select appropriate ICIs. In this review, we summarize the findings on the immune microenvironment and immunosuppressive approaches focused on monoclonal antibodies against cytotoxic T lymphocyte-associated protein 4 and programmed cell death protein 1 for HCC. We also describe ongoing treatment modalities, including adoptive cell transfer-based therapies and future areas of exploration based on recent literature. The results of pre-clinical studies using immunological classification and animal models will contribute to the development of biomarkers that predict the efficacy of immunosuppressive therapy and aid in the selection of appropriate strategies for HCC treatment.

Combining PD-1 Inhibitor with VEGF/VEGFR2 Inhibitor in Chemotherapy: Report of a Patient with End-Stage Cholangiocarcinoma and Review of Literature

BACKGROUND

Cholangiocarcinoma is the second-largest liver cancer, and develops from the biliary epithelium, where it discretely progresses. Unfortunately, many patients miss the opportunity of performing surgery when diagnosed with cholangiocarcinoma, and due to its chemotherapeutic insensitivity, its control has always been considered difficult.

OBJECTIVE

Here, we present a case of stage 4 cholangiocarcinoma being controlled by the combination of chemotherapy with PD-1 and VEGF/VEGFR2 inhibitors.

CASE PRESENTATION

The patient is a 58-year-old male who was diagnosed with a progressed cholangiocarcinoma 2 years ago. From the beginning, metastases were discovered in multiple places, and the patient was unsuccessfully treated with 3 chemotherapy regimens. Therefore, a new therapeutic method was considered, and that involved the testing of a new combination of chemotherapy with PD-1 and VEGF/VEGFR2 inhibitors.

RESULTS

After 6 courses of treatment with this combination, the patient's lesions became smaller and stable.

CONCLUSION

Our case highlights the possibility of combining chemotherapy with PD-1 and VEGF/ VEGFR2 inhibitors for the treatment of cholangiocarcinoma patients. This combination may herald new hope for patients who run out of regimens.

Mechanisms of PD-L1 Regulation in Malignant and Virus-Infected Cells

Programmed cell death protein 1 (PD-1), a receptor on T cells, and its ligand, PD-L1, have been a topic of much interest in cancer research. Both tumour and virus-infected cells can upregulate PD-L1 to suppress cytotoxic T-cell killing. Research on the PD-1/PD-L1 axis has led to the development of anti-PD-1/PD-L1 immune checkpoint blockades (ICBs) as promising cancer therapies. Although effective in some cancer patients, for many, this form of treatment is ineffective due to a lack of immunogenicity in the tumour microenvironment (TME). Despite the development of therapies targeting the PD-1/PD-L1 axis, the mechanisms and pathways through which these proteins are regulated are not completely understood. In this review, we discuss the latest research on molecules of inflammation and innate immunity that regulate PD-L1 expression, how its expression is regulated during viral infection, and how it is modulated by different cancer therapies. We also highlight existing research on the development of different combination therapies with anti-PD-1/PD-L1 antibodies. This information can be used to develop better cancer immunotherapies that take into consideration the pathways involved in the PD-1/PD-L1 axis, so these molecules do not reduce their efficacy, which is currently seen with some cancer therapies. This review will also assist in understanding how the TME changes during treatment, which will provide further rationale for combination therapies.

Combination Immunotherapy for Hepatocellular Carcinoma: Where Are We Currently?

The past decade has seen a rise in the availability of breakthrough therapeutic strategies for treatment of hepatocellular carcinoma (HCC). A tumor microenvironment in HCC is regulated by various immunotolerance mechanisms; therefore, therapeutic strategies aiming at disrupting tumor immune tolerance are becoming attractive curative options in HCC. Immune checkpoint inhibitors have demonstrated impressive effectiveness in HCC, including in sorafenib-unresponsive patients. Synergistic approaches with checkpoint inhibitors (anti-PD-1/PD-L1 and CTLA-4) and antiangiogenic drugs are burgeoning as first-line treatment therapeutic modalities in HCC.

Atezolizumab and bevacizumab combination compared with sorafenib as the first-line systemic treatment for patients with unresectable hepatocellular carcinoma: A cost-effectiveness analysis in China and the United states

BACKGROUND & AIMS

In patients with unresectable hepatocellular carcinoma (HCC), the combination of atezolizumab and bevacizumab improved progression-free survival (PFS) and overall survival compared with sorafenib in the IMbrave150 trial. However, whether the price of the combination could be affordable is unknown. The current study assessed the cost-effectiveness of the combination of atezolizumab and bevacizumab as first-line systemic therapy for patients with unresectable HCC from the Chinese and American payers' perspective.

METHODS

A Markov model was built based on a global, multicentre, open-label, phase III randomized trial (IMbrave150, NCT03434379) that included three states of the patient's health: stable disease (SD), progressive disease (PD) and death. Data for all medical costs were acquired from the Red Book, published literature and West China Hospital. Quality-adjusted life years (QALYs) and incremental cost-effectiveness ratios (ICERs) were the primary outcomes. Sensitivity analyses were performed to evaluate the model uncertainty.

RESULTS

The treatment consisting of a combination of atezolizumab and bevacizumab yielded an additional 0.53 QALYs compared with sorafenib alone, leading to an ICER of $145,546.21 per QALY in China and $168,030.21 per QALY in the USA, both beyond the willing-to-pay threshold ($28,527.00/QALY in China and $150,000.00 /QALY in the USA). The utility of the PD state was the most influential factor in the Chinese model, and the American model was the most sensitive to the price of sorafenib. The results of the models were robust across sensitivity analyses.

CONCLUSION

The combination of atezolizumab and bevacizumab was not a cost-effective strategy for the first-line systemic treatment of unresectable HCC from the Chinese and American payers' perspective.

Initial Experience of Atezolizumab Plus Bevacizumab for Advanced Hepatocellular Carcinoma in Clinical Practice

BACKGROUND/AIM

The aim of this study was to investigate the outcomes of atezolizumab plus bevacizumab in patients with advanced hepatocellular carcinoma (HCC), including those with disease refractory to lenvatinib, in clinical practice.

PATIENTS AND METHODS

Of 34 patients treated with atezolizumab plus bevacizumab, a total of 23, including 16 with lenvatinib failure, were enrolled in this retrospective study. The adverse events, changes in liver function and antitumor responses at 6 weeks after starting therapy were evaluated.

RESULTS

The incidence of grade 3 adverse events was low, at 13.0%. Albumin-bilirubin scores did not worsen at 3 and 6 weeks compared to baseline. The objective response rate and disease control rate at 6 weeks were 17.4% and 78.3% according to Response Evaluation Criteria in Solid Tumors (RECIST), and 30.4% and 78.3% according to modified RECIST, respectively.

CONCLUSION

Our results suggest that atezolizumab plus bevacizumab might have potential therapeutic safety and efficacy in patients with advanced HCC, including those with disease refractory to lenvatinib. Further studies are needed to confirm the outcomes of atezolizumab plus bevacizumab after lenvatinib failure.

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.

Combination therapy for advanced hepatocellular carcinoma: do we see the light at the end of the tunnel?

Importance

Combination therapies of anti-PD-1 and anti-angiogenesis regimens are emerging rapidly and exhibit more promising anti-tumor efficacy for advanced hepatocellular carcinoma (HCC), and consistently it is the hotspot in clinical studies.

Objective

To elaborate several issues which are warranted further consideration as more regimens are being investigated in combination therapies.

Evidence Review

We searched PubMed, MEDLINE, Cochrane Library and Google Scholar by 2021 February for publications on combination therapies for HCC.

Findings

Several clinical issues are worth reconsidering, such as the evaluation on appropriate primary endpoints in phase III clinical trials as for different practical problems, the translation of surrogate endpoint objective response rate (ORR) benefits into overall survival (OS) benefits, and whether conversion surgery contributes to initial expectations of long-term survival or not. New concepts in novel immunotherapy and targeted therapy in combination with loco-regional therapies may improve overall survival for HCC.

Conclusions and Relevance for Reviews

Comprehensive understanding of the mechanism of immunotherapy and targeted therapy contributes to better prognosis of advanced HCC and more explorative combination therapies are needed.

A snapshot of the PD-1/PD-L1 pathway

Cancer cells can evade the attack from host immune systems via hijacking the regulatory circuits mediated by immune checkpoints. Therefore, reactivating the antitumor immunity by blockade of immune checkpoints is considered as a promising strategy to treat cancer. Programmed death protein 1 (PD-1) and its ligand programmed death-ligand 1 (PD-L1) are critical immune checkpoint proteins that responsible for negative regulation of the stability and the integrity of T-cell immune function. Anti-PD-1/PD-L1 drugs have been developed for immune checkpoint blockade and can induce clinical responses across different types of cancers, which provides a new hope to cure cancer. However, the patients' response rates to current anti-PD-1 or anti-PD-L1 therapies are still low and many initial responders finally develop resistance to these therapies. In this review, we provides a snapshot of the PD-1/PD-L1 molecular structure, mechanisms controlling their expression, signaling modulated by PD-1/PD-L1, current anti-PD-1/PD-L1 therapies, and the future perspectives to overcome the resistance.

Biochemical predictors of response to immune checkpoint inhibitors in unresectable hepatocellular carcinoma

Hepatocellular carcinoma (HCC) represents the most commonly diagnosed liver cancer worldwide, and the overall survival of patients with unresectable disease is poor. In the last five years, immune checkpoint inhibitors (ICIs) have revolutionized the treatment scenario of several hematological and solid tumors, and these agents have been actively explored in unresectable HCC. Firstly, promising findings of phase I and II clinical studies reporting durable responses and a tolerable safety profile have led to the assessment of ICIs as single agents in phase III clinical studies; however, the latter have provided controversial results, and the activity of ICI monotherapy seems limited to a small subgroup of patients. Conversely, the IMbrave150 trial recently showed that, among patients with previously untreated unresectable HCC, treatment with atezolizumab plus bevacizumab resulted in significantly longer overall survival and progression-free survival compared to sorafenib monotherapy. In addition, the activity of several other ICIs is under investigation, as combination immunotherapy as well as combinations of immunotherapy with antiangiogenic agents. Nonetheless, there are currently no validated predictive biomarkers able to guide treatment choice in this setting, where the identification of specific predictors of response to ICIs represents a major challenge. In this review, we aim to provide a critical overview of recent evidence on biochemical predictors of response to ICIs in patients with unresectable HCC, especially focusing on PD-L1, TMB, MSI, and other emerging biomarkers.

Heterogeneity of Response and Immune System Activity during Treatment with Nivolumab in Hepatocellular Carcinoma: Results from a Single-Institution Retrospective Analysis

Simple Summary

Immunotherapy is an emerging treatment in hepatocellular carcinoma, both alone and in combination. The advent of this new approach raises challenges for the interpretation of response assessment due to the peculiar patterns of mixed responses, pseudoprogression and hyperprogression. Furthermore, there are no criteria to drive selection of treatment strategy. We analyzed data from the first 10 patients treated with nivolumab in our institution and we identified different patterns of response according to the lesion’s site. Furthermore, we analyzed blood samples from the first four patients, and found differences, between a patient with shorter survival and the other three, that may provide insight into mechanisms underlying the different activities of nivolumab. Although we analyzed data from a small number of patients, our results can help to understand mechanisms of immunotherapy activity in order to define the most appropriate treatment strategy for each patient.

Abstract

Treatment of hepatocellular carcinoma (HCC) is rapidly evolving, with many new therapeutic options; in particular, immunotherapy (IT) is acquiring a major role, even in combination regimens. Despite these promising results, an important limitation is the lack of prognostic and predictive factors that prevent provision of a tool for patient stratification in order to select the most appropriate strategy. Furthermore, response assessment can be challenging with IT due to peculiar patterns such as mixed responses or pseudoprogression. We analyzed biological and clinical features from the first 10 HCC patients treated with nivolumab in our institution. Analysis of patterns of response in CT assessment revealed complete response in pulmonary lesions, along with heterogeneous behavior in the liver and other organ lesions. Peripheral blood mononuclear cells (PBMC) analysis in the first four patients showed unique alterations in a patient with poor prognosis, both at baseline (lower percentage of effector T cells, higher percentage of natural killer T [NK/T] cells) and during treatment with nivolumab (decrease in nonclassical monocytes, increase in monocytic myeloid-derived suppressor cells [MO-MDSC]), suggesting a possible prognostic role for these features. Although obtained in a small cohort of patients, our results open a new perspective for understanding mechanisms underlying IT outcomes in HCC patients.

Characteristics of the Tumor Microenvironment That Influence Immune Cell Functions: Hypoxia, Oxidative Stress, Metabolic Alterations

Immunotherapy (IMT) is now a core component of cancer treatment, however, many patients do not respond to these novel therapies. Investigating the resistance mechanisms behind this differential response is now a critical area of research. Immune-based therapies, particularly immune checkpoint inhibitors (ICI), rely on a robust infiltration of T-cells into the tumor microenvironment (TME) for an effective response. While early efforts relied on quantifying tumor infiltrating lymphocytes (TIL) in the TME, characterizing the functional quality and degree of TIL exhaustion correlates more strongly with ICI response. Even with sufficient TME infiltration, immune cells face a harsh metabolic environment that can significantly impair effector function. These tumor-mediated metabolic perturbations include hypoxia, oxidative stress, and metabolites of cellular energetics. Primarily through HIF-1-dependent processes, hypoxia invokes an immunosuppressive phenotype via altered molecular markers, immune cell trafficking, and angiogenesis. Additionally, oxidative stress can promote lipid peroxidation, ER stress, and Treg dysfunction, all associated with immune dysregulation. Finally, the metabolic byproducts of lipids, amino acids, glucose, and cellular energetics are associated with immunosuppression and ICI resistance. This review will explore these biochemical pathways linked to immune cell dysfunction in the TME and highlight potential adjunctive therapies to be used alongside current IMT.

Recent Advances in Systemic Therapy for Hepatocellular Carcinoma in an Aging Society: 2020 Update

Systemic therapy for hepatocellular carcinoma (HCC) has changed markedly since the introduction of the molecular targeted agent sorafenib in 2007. Sorafenib increased the available treatment options for patients with extrahepatic spread and vascular invasion and improved survival in patients with advanced HCC; however, various shortcomings such as low response rates and relatively high toxicity (e.g., hand-foot skin reaction) prompted concerted efforts aimed at developing new molecular targeted agents to provide more treatment options and second-line agents for patients with disease progression or intolerance to sorafenib. Despite many attempts to develop new drugs between 2007 and 2016, all first-line and second-line clinical trials conducted during this period failed. However, between 2017 and 2019, 4 drugs (lenvatinib as a first-line agent and regorafenib, cabozantinib, and ramucirumab as second-line agents) emerged in quick succession from clinical trials and became available for clinical use. In addition, nivolumab and pembrolizumab were approved as second-line agents after sorafenib. A recent phase III trial (IMbrave150) showed that combination immunotherapy with atezolizumab plus bevacizumab increases overall survival compared with sorafenib therapy; Food and Drug Agency already approved this combination therapy, and worldwide approval is expected soon. This review describes the recent advances in systemic therapy and the use of tyrosine kinase inhibitors (sorafenib, lenvatinib, regorafenib, and cabozantinib), monoclonal antibodies (ramucirumab and bevacizumab), and immune checkpoint inhibitors (nivolumab, pembrolizumab, and atezolizumab) in elderly patients and the similarity of their efficacy and safety profiles to those in the general population.

Synergism between anti-angiogenic and immune checkpoint inhibitor drugs: A hypothesis

Hepatocellular cancer (HCC) and renal cell cancer (RCC) are singularly resistant to conventional chemotherapy drugs but therapies targeting the supporting stroma have significantly altered their management. Two recent trials combining anti-angiogenic (AA) agents with immune checkpoint inhibitors (ICIs)- the IMbrave150 and IMmotion151 - have reported impressive progress over targeted agents. It has been suggested that bevacizumab, by improving tissue perfusion, changes the immune suppressive tumour microenvironment to an immune stimulatory one where the ICIs can be more effective. This hypothesis proposes an alternative explanation: That bevacizumab, by increasing tissue hypoxia, amplifies the mutational burden of the tumour by stress-induced mutagenesis, creating a hypermutator profile, which is more vulnerable to the ICI drug, atezolizumab. Additionally, ICIs are known to cause hyperprogression in some tumours, and bevacizumab could provide further benefit by starving these rapidly proliferative tumours of blood supply and nutrients.

Cold-Inducible RNA Binding Protein as a Vaccination Platform to Enhance Immunotherapeutic Responses Against Hepatocellular Carcinoma

Therapies based on immune checkpoint inhibitors (ICPI) have yielded promising albeit limited results in patients with hepatocellular carcinoma (HCC). Vaccines have been proposed as combination partners to enhance response rates to ICPI. Thus, we analyzed the combined effect of a vaccine based on the TLR4 ligand cold-inducible RNA binding protein (CIRP) plus ICPI. Mice were immunized with vaccines containing ovalbumin linked to CIRP (OVA-CIRP), with or without ICPI, and antigen-specific responses and therapeutic efficacy were tested in subcutaneous and orthotopic mouse models of liver cancer. OVA-CIRP elicited polyepitopic T-cell responses, which were further enhanced when combined with ICPI (anti-PD-1 and anti-CTLA-4). Combination of OVA-CIRP with ICPI enhanced ICPI-induced therapeutic responses when tested in subcutaneous and intrahepatic B16-OVA tumors, as well as in the orthotopic PM299L HCC model. This effect was associated with higher OVA-specific T-cell responses in the periphery, although many tumor-infiltrating lymphocytes still displayed an exhausted phenotype. Finally, a new vaccine containing human glypican-3 linked to CIRP (GPC3-CIRP) induced clear responses in humanized HLA-A2.01 transgenic mice, which increased upon combination with ICPI. Therefore, CIRP-based vaccines may generate anti-tumor immunity to enhance ICPI efficacy in HCC, although blockade of additional checkpoint molecules and immunosuppressive targets should be also considered.

Immunostimulatory biomaterials to boost tumor immunogenicity

Cancer immunotherapy is exhibiting great promise as a new therapeutic modality for cancer treatment. However, immunotherapies are limited by the inability of some tumors to provoke an immune response. These tumors with a 'cold' immunological phenotype are characterized by low numbers of tumor-infiltrating lymphocytes, high numbers of immunosuppressive leukocytes (e.g. regulatory T cells, tumor-associated macrophages), and high production of immune-dampening signals (e.g. IL-10, TGF-β, IDO-1). Strategies to boost the aptitude of tumors to initiate an immune response (i.e. boost tumor immunogenicity) will turn 'cold' tumors 'hot' and augment the anti-tumor efficacy of current immunotherapies. Approaches to boost tumor immunogenicity already show promise; however, multifaceted delivery and immunobiology challenges exist. For instance, systemic delivery of many immune-stimulating agents causes off-target toxicity and/or the development of autoimmunity, limiting the administrable dose below the threshold needed to achieve efficacy. Moreover, once administered in vivo, molecules such as the nucleic acid-based agonists for many pattern recognition receptors are either rapidly cleared or degraded, and don't efficiently traffic to the intracellular compartments where the receptors are located. Thus, these nucleic acid-based drugs are ineffective without a delivery system. Biomaterials-based approaches aim to enhance current strategies to boost tumor immunogenicity, enable novel strategies, and spare dose-limiting toxicities. Here, we review recent progress to improve cancer immunotherapies by boosting immunogenicity within tumors using immunostimulatory biomaterials.

Exploratory Analysis of Lenvatinib Therapy in Patients with Unresectable Hepatocellular Carcinoma Who Have Failed Prior PD-1/PD-L1 Checkpoint Blockade

Although programmed cell death protein 1 (PD-1)/PD-ligand 1 (PD-L1) blockade is effective in a subset of patients with hepatocellular carcinoma (HCC), its therapeutic response is still unsatisfactory. Alternatively, the potential impact of the lenvatinib in patients who showed tumor progression on PD-1/PD-L1 blockade is unknown. In this work, we evaluated the safety and efficacy of lenvatinib administration after PD-1/PD-L1 checkpoint blockade. The outcome and safety of lenvatinib administered after PD-1/PD-L1 blockade failure was analyzed retrospectively in 36 patients. Tumor growth was assessed every 4-8 weeks using modified Response Evaluation Criteria in Solid Tumors. The mean relative dose intensity of lenvatinib was 87.6% and 77.8% in patients receiving a starting dose of 8 (interquartile range (IQR), 77.5-100.0) mg and 12 (IQR, 64.4-100.0) mg, respectively. Since lenvatinib therapy initiation, the median progression-free survival was 10 months (95% confidence interval (CI): 8.3-11.8) and the median overall survival was 15.8 months (95% CI: 8.5-23.2). The objective response rate was 55.6%, and the disease control rate was 86.1%. No particular safety concerns were observed. Lenvatinib demonstrated considerable antitumor effects with acceptable safety in patients with progressive and unresectable HCC when administered right after PD-1/PD-L1 blockade failure.

Vascular Complications in Patients with Hepatocellular Carcinoma Treated with Sorafenib

Simple Summary

Inhibition of vascular endothelial growth factor receptor (VEGFR) signaling is associated with an increased risk of thromboembolic and bleeding complications in cancer patients and may cause fatal side effects. The multityrosine kinase inhibitor sorafenib represents an important treatment option for patients with hepatocellular carcinoma (HCC), as all currently approved second-line treatments have only been approved in sorafenib-experienced patients. However, safety concerns regarding sorafenib treatment in patients with cardiovascular disease have been raised. Therefore, we retrospectively analyzed the incidence of arterial/venous thromboembolic and bleeding complications in 252 patients with HCC treated with sorafenib. Importantly, the incidence of arterial/venous thromboembolic events was low even though more than half of patients had advanced liver dysfunction and a substantial cardiovascular risk according to Framingham risk score. Bleeding complications occurred in every fifth patient. In conclusion, sorafenib represents a safe treatment option even in patients with an increased cardiovascular risk.

Abstract

VEGF(R)-targeted therapies are associated with an increased risk of thromboembolism and bleeding, which might be pronounced in patients with increased cardiovascular risk. Nevertheless, sorafenib represents an important treatment option in patients with hepatocellular carcinoma (HCC). We retrospectively investigated the risk of arterial/venous thromboembolic and bleeding events in 252 patients treated with sorafenib for HCC between 05/2006 and 03/2020 at the Medical University of Vienna. Cardiovascular risk was assessed using Framingham score. Eight patients (3.2%) experienced 11 arterial/venous thromboembolic events. Only two patients (0.8%) developed arterial thromboembolism even though cardiovascular risk was low, intermediate, and high in 15 (8.7%), 104 (60%), and 54 (31.2%) of 173 assessable patients. Median overall survival (OS) was shorter in the high risk vs. low/intermediate risk group 7.4 (95% CI: 3.4–11.3) vs. 10.0 (95% CI: 6.8–13.2 months) and independently associated with OS in multivariable analysis HR: 1.53 (95% CI: 1.07–2.19; p = 0.019). Forty-eight (19%) patients experienced a bleeding, most commonly gastrointestinal bleeding (14%) followed by epistaxis (4.7%). Advanced liver dysfunction was not associated with an increased incidence of bleeding/venous thromboembolism. Sorafenib represents a safe treatment option even in patients with increased cardiovascular risk. Bleeding complications were comparable with previous reports, even though patients with more advanced liver disease were included.

Emerging roles and the regulation of aerobic glycolysis in hepatocellular carcinoma

Liver cancer has become the sixth most diagnosed cancer and the fourth leading cause of cancer death worldwide. Hepatocellular carcinoma (HCC) is responsible for up to 75–85% of primary liver cancers, and sorafenib is the first targeted drug for advanced HCC treatment. However, sorafenib resistance is common because of the resultant enhancement of aerobic glycolysis and other molecular mechanisms. Aerobic glycolysis was firstly found in HCC, acts as a hallmark of liver cancer and is responsible for the regulation of proliferation, immune evasion, invasion, metastasis, angiogenesis, and drug resistance in HCC. The three rate-limiting enzymes in the glycolytic pathway, including hexokinase 2 (HK2), phosphofructokinase 1 (PFK1), and pyruvate kinases type M2 (PKM2) play an important role in the regulation of aerobic glycolysis in HCC and can be regulated by many mechanisms, such as the AMPK, PI3K/Akt pathway, HIF-1α, c-Myc and noncoding RNAs. Because of the importance of aerobic glycolysis in the progression of HCC, targeting key factors in its pathway such as the inhibition of HK2, PFK or PKM2, represent potential new therapeutic approaches for the treatment of HCC.

Percutaneous Ablation-Induced Immunomodulation in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common causes of cancer-related deaths worldwide and its incidence is rising. Percutaneous locoregional therapies, such as radiofrequency ablation and microwave ablation, are widely used as curative treatment options for patients with small HCC, but their effectiveness remains restricted because of the associated high rate of recurrence, occurring in about 70% of patients at five years. These thermal ablation techniques have the particularity to induce immunomodulation by destroying tumours, although this is not sufficient to raise an effective antitumour immune response. Ablative therapies combined with immunotherapies could act synergistically to enhance antitumour immunity. This review aims to understand the different immune changes triggered by radiofrequency ablation and microwave ablation as well as the interest in using immunotherapies in combination with thermal ablation techniques as a tool for complementary immunomodulation.

Establishing peripheral PD-L1 as a prognostic marker in hepatocellular carcinoma patients: how long will it come true?

BACKGROUND

The prognostic role of intratumoral programmed cell death ligand 1 (PD-L1) expression in hepatocellular carcinoma (HCC) has been investigated by several meta-analyses. However, the prognostic value of pretreatment peripheral PD-L1 (PPPD-L1) level in HCC remains undetermined. Thus, this systemic review aimed to establish PPPD-L1 as a new prognostic marker in HCC according to available evidence.

METHODS

Case-control studies investigating the prognostic role of PPPD-L1 in HCC were systemically sought in the database of PubMed and Web of Science until March 25th, 2020. Our main concern is survival results, including overall survival (OS), disease-free survival (DFS), and progression-free survival (PFS). The combined results were summarized in narrative form according to data extracted from each included study.

RESULTS

Finally, nine studies published from 2011 to 2019, were incorporated into this systemic review. Among these, six studies evaluated the PD-L1 expression by enzyme-linked immunosorbent assay (ELISA) from blood serum, and three studies evaluated the PD-L1 expression by flow cytometric analysis from peripheral blood mononuclear cells (PBMC). According to the extracted evidence, high PPPD-L1 expression, measured in either blood serum or PBMC, is associated with poor OS, poor DFS, and poor PFS. Meanwhile, PPPD-L1 was also correlated with enlarged tumor size and more likely with advanced tumor stage as well as vascular invasion.

CONCLUSION

High PPPD-L1 level is associated with increased mortality rate and increased recurrence rate in HCC. As a convenient serum marker, PPPD-L1 could be a promising marker of prognosis in HCC patients.