Unmasking of alpha-fetoprotein-specific CD4(+) T cell responses in hepatocellular carcinoma patients undergoing embolization

Interventional radiology meets immuno-oncology for hepatocellular carcinoma

Locoregional and systemic therapies are the most used treatment options for patients with hepatocellular carcinoma (HCC). Interventional radiologists have improved and developed novel protocols and devices for both intratumoural ablative approaches with curative intent and various transarterial intrahepatic treatment options, which have continuously improved patient outcomes. Two large phase III randomised clinical trials have demonstrated the efficacy of different immune checkpoint inhibitors either as single agents or in combination in the first-line setting and immunotherapy has become the standard first-line treatment option for patients with advanced HCC. Herein, we discuss advances and perspectives in the area of interventional radiology (IR) and immune-oncology (IO). We summarise results from recent studies and provide an overview of ongoing studies in IR and IO. Based on the significant advances in both areas, we propose that IR and IO need to cover the emerging "discipline" of IR-IO, in which we develop and test novel approaches to combine locoregional therapies with immunotherapy, in order to develop sufficient evidence for them to be considered standard of care for patients with HCC in the near future.

Pathologic Complete Response After Gastric Artery Chemoembolization Combined With Tislelizumab for Neoadjuvant Therapy of Locally Advanced Gastric Cancer: A Case Report

Gastric cancer is the most common type of gastrointestinal cancer in China which about 80% of patients are locally advanced or advanced when diagnosed. Surgery along brings high recurrence rate for locally advanced gastric cancer (LAGC), and neoadjuvant therapies are needed. The use of programmed cell death-1 (PD-1)/programmed death-ligand 1 inhibitor nowadays improved the disease-free survival for LAGC, however, only <35% of patients achieved pathologic complete response (pCR) after neoadjuvant therapy nowadays. Therefore, new regimens are needed to be investigated. Gastric artery chemoembolization is applied to metastasis gastric cancer and researches showed interventional therapy can enhance the antitumor effect of PD-1 inhibitor. Here, for the first time, we combined gastric artery chemoembolization with tislelizumab (a PD-1 inhibitor) for neoadjuvant therapy of a patient with LAGC. The patient achieved pCR after a D2 resection and tumor regression grade score was 1. After surgery, the patient received tislelizumab 200 mg per 3 weeks, and showed no sign of recurrence after 6 months of follow-up. The study indicated the use of tislelizumab and gastric artery chemoembolization for neoadjuvant therapy may bring a better pCR rate and prognosis of LAGC.

Immune Effects of Intra-Arterial Liver-Directed Therapies

Image-guided intra-arterial locoregional therapies (LRTs) such as transarterial embolization, transarterial chemoembolization, and transarterial radioembolization exhibit effects on the immune system. Understanding the humoral (cytokine, chemokine, and growth factor) and cellular (T cell, neutrophil, dendritic cell, and macrophage) mechanisms underlying the immune effects of LRT is crucial to designing rational and effective combinations of immunotherapy and interventional radiology procedures. This article aims to review the immune effects of intra-arterial LRTs and provide insight into strategies to combine LRTs with systemic immunotherapy.

Immunotherapy combined with local therapy in the late-line treatment of repair-proficient (pMMR)/microsatellite stable (MSS) metastatic colorectal cancer

Colorectal cancer (CRC) is one of the most common malignancies, and at the initial visit, most patients are diagnosed with metastatic CRC (mCRC). However, immunotherapy is only and highly effective in a very small proportion of patients with mCRC having mismatch repair defect (dMMR)/high microsatellite instability, and the majority of the patients with mCRC having mismatch repair proficient (pMMR)/microsatellite stability (MSS) cannot benefit from it. At present, many clinical studies of immunotherapy combined with tyrosine kinase inhibitors (TKIs) are trying to regulate the immune microenvironment of pMMR/MSS mCRC, transforming a "cold tumor" into a "hot tumor," which has not only surprising effects but also certain limitations, i.e., the response could not be specific to metastasis. Therefore, regarding the bottleneck encountered by immunotherapy in patients with patients pMMR/MSS mCRC, this study summarized current research and possible mechanisms of immunotherapy combined with local therapy for metastasis, including radiotherapy, ablation, and transcatheter arterial chemoembolization.

Hydrogel drug delivery systems for minimally invasive local immunotherapy of cancer

Although systemic immunotherapy has achieved durable responses and improved survival for certain patients and cancer types, low response rates and immune system-related systemic toxicities limit its overall impact. Intratumoral (intralesional) delivery of immunotherapy is a promising technique to combat mechanisms of tumor immune suppression within the tumor microenvironment and reduce systemic drug exposure and associated side effects. However, intratumoral injections are prone to variable tumor drug distribution and leakage into surrounding tissues, which can compromise efficacy and contribute to toxicity. Controlled release drug delivery systems such as in situ-forming hydrogels are promising vehicles for addressing these challenges by providing improved spatio-temporal control of locally administered immunotherapies with the goal of promoting systemic tumor-specific immune responses and abscopal effects. In this review we will discuss concepts, applications, and challenges in local delivery of immunotherapy using controlled release drug delivery systems with a focus on intratumorally injected hydrogel-based drug carriers.

Combination Therapy of Immune Checkpoint Inhibitors with Locoregional Therapy for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is estimated to be the fourth leading cause of cancer-related deaths globally, and its overall prognosis is dismal because most cases are diagnosed at a late stage and are unamenable to curative treatment. The emergence of immune checkpoint inhibitors (ICIs) has dramatically improved the therapeutic efficacy for advanced hepatocellular carcinoma; however, their response rates remain unsatisfactory, partly because >50% of HCC exhibit an ICI-nonresponsive tumor microenvironment characterized by a paucity of cytotoxic T cells (immune-cold), as well as difficulty in their infiltration into tumor sites (immune excluded). To overcome this limitation, combination therapies with locoregional therapies, including ablation, transarterial embolization, and radiotherapy, which are usually used for early stage HCCs, have been actively explored to enhance ICI efficacy by promoting the release of tumor-associated antigens and cytokines, and eventually accelerating the so-called cancer-immunity cycle. Various combination therapies have been investigated in early- to late-phase clinical trials, and some have shown promising results. This comprehensive article provides an overview of the immune landscape for HCC to understand ICI efficacy and its limitations and, subsequently, reviews the status of combinatorial therapies of ICIs with locoregional therapy for HCC.

Is the CRAFITY score a superior predictor of prognosis and adverse events in hepatocellular carcinoma patients treated with locoregional-immunotherapy?

BACKGROUND

The level of C‑reactive protein (CRP) and alpha‑fetoprotein (AFP) in immunotherapy (CRAFITY) score was associated with the prognosis of hepatocellular carcinoma (HCC) patients treated with immunotherapy. Based on the CRAFITY score, this study aimed to investigate the efficacy and safety of locoregional-immunotherapy for treating HCC patients.

METHODS

HCC patients who received locoregional-immunotherapy were consecutively recruited at Sun Yat-sen University Cancer Center in 2019. CRAFITY 0 score was defined as the AFP level below 100 ng/ml and a CRP level of less than 1 mg/dl, CRAFITY 1 score was defined as the AFP level of at least 100 ng/ml or the CRP level of at least 1 mg/dl, and CRAFITY 2 score was defined as both the AFP level over 100 ng/ml and the CRP level of more than 1 mg/dl. The primary outcomes were progression-free survival (PFS) and overall survival (OS). The second outcomes were tumor response rate and treatment-related adverse events (AEs).

RESULTS

The median PFS for HCC patients with the CRAFITY 0 score was not estimable. The PFS was 11.0 months [95% confidence interval (CI) 7.2-14.9] and 6.0 months (95% CI 4.2-7.8) for patients with CRAFITY 1 and 2 scores, respectively, with a significant difference between the two groups (p < 0.001). HCC patients with CRAFITY 0, 1, and 2 scores had 3 years OS rates of 63.8%, 60.8%, and 32.1%, respectively, with statistical differences among the three groups (p < 0.001). Patients with the CRAFITY 2 score were more likely to experience fever than those with other scores (p < 0.05). A greater CRAFITY score was correlated with a higher incidence of grade 3 and above liver injury (p < 0.01).

CONCLUSIONS

The CRAFITY score is a superior predictor of prognosis and treatment-related AEs in HCC patients treated with locoregional-immunotherapy.

Achievement of Complete Response and Drug-Free Status by Atezolizumab plus Bevacizumab Combined with or without Curative Conversion in Patients with Transarterial Chemoembolization-Unsuitable, Intermediate-Stage Hepatocellular Carcinoma: A Multicenter Proof-Of-Concept Study

Introduction

Atezolizumab plus bevacizumab therapy is extremely effective in the treatment of intermediate-stage hepatocellular carcinoma (HCC), with a response rate of 44%, as reported in the IMbrave150 trial. When tumor shrinkage is obtained, achieving complete response (CR) is possible in many cases using curative conversion with resection, ablation, or superselective transarterial chemoembolization (TACE) with curative intent. This concept, i.e., curative conversion by combining systemic therapy and locoregional therapy, has not been reported before. This multicenter proof-of-concept study was conducted to show the value of curative conversion in immunotherapy-treated intermediate-stage HCC meeting TACE-unsuitable criteria.

Methods

This study included 110 consecutive Child-Pugh A patients who received atezolizumab plus bevacizumab as first-line treatment for unresectable and TACE-unsuitable intermediate-stage HCC at seven centers in Japan. CR rate, drug-free rate, time to CR, change in liver function, efficacy in positron emission tomography (PET)-positive HCC, progression-free survival (PFS), and overall survival (OS) were assessed in patients who achieved CR using resection, ablation, superselective TACE with curative intent following atezolizumab plus bevacizumab or atezolizumab plus bevacizumab alone.

Results

Clinical or pathological CR was achieved in 38 patients (35%) (median observation period: 21.2 months). The modalities of curative conversion in 35 patients were as follows: resection, 7; ablation, 13; and superselective TACE, 15. Three patients achieved clinical CR with atezolizumab plus bevacizumab therapy alone. Among the 38 CR patients, 25 achieved drug-free status. PFS was not reached, and 3 patients experienced recurrence after reaching CR. Regarding OS, there were no deaths in any of the CR patients. The albumin-bilirubin score did not deteriorate after locoregional therapy or resection. Of seven PET-positive patients who achieved CR with atezolizumab plus bevacizumab followed by curative conversion, five achieved drug-free status.

Conclusion

The achievement of CR rate by curative conversion in patients treated with atezolizumab plus bevacizumab as the preceding therapy for unresectable and TACE-unsuitable intermediate-stage HCC was 35%. Overall, 23% of patients achieved drug-free status and no recurrence was observed from this patient subgroup with CR and drug-free status. Thus, achieving CR and/or drug-free status should be a therapeutic goal for patients with intermediate-stage HCC without vascular invasion or extrahepatic spread.

Peripheral blood-based cell signature indicates response to interstitial brachytherapy in primary liver cancer

PURPOSE

Biomarkers are essential to implement personalized therapies in cancer treatment options. As primary liver tumors are increasing and treatment is coupled to liver function and activation of systemic cells of the immune system, we investigated blood-based cells for their ability to predict response to local ablative therapy.

METHODS

We analyzed peripheral blood cells in 20 patients with primary liver cancer at baseline and following brachytherapy. In addition to platelets, leukocytes, lymphocytes, monocytes, neutrophils and most common ratios PLR, LMR, NMR and NLR, we investigated T cell and NKT cell populations of 11 responders and 9 non-responders using flow cytometry.

RESULTS

We have found a peripheral blood cell signature that differed significantly between responders and non-responders treated with interstitial brachytherapy (IBT). At baseline, non-responders featured higher numbers of platelets, monocytes and neutrophils, a higher platelet-to-lymphocyte ratio and an increase in the NKT cell population with a concurrent reduction in CD16 + NKT cells. Simultaneously, a lower percentage of CD4 + T cells was present in non-responders, as also reflected in a lower CD4/8 ratio. CD45RO + memory cells were lower in both, CD4 + and CD8 + T cell populations whereas PD-1 + T cells were only present in the CD4 + T cell population.

CONCLUSION

Baseline blood-based cell signature may function as a biomarker to predict response following brachytherapy in primary liver cancer.

Friend or Foe? Locoregional Therapies and Immunotherapies in the Current Hepatocellular Treatment Landscape

Over the last several decades, a number of new treatment options for patients with hepatocellular carcinoma (HCC) have been developed. While treatment decisions for some patients remain clear cut, a large numbers of patients have multiple treatment options, and it can be hard for multidisciplinary teams to come to unanimous decisions on which treatment strategy or sequence of treatments is best. This article reviews the available data with regard to two treatment strategies, immunotherapies and locoregional therapies, with a focus on the potential of locoregional therapies to be combined with checkpoint inhibitors to improve outcomes in patients with locally advanced HCC. In this review, the available data on the immunomodulatory effects of locoregional therapies is discussed along with available clinical data on outcomes when the two strategies are combined.

Efficacy and safety of Lenvatinib-based combination therapies for patients with unresectable hepatocellular carcinoma: a single center retrospective study

Background

Reports on Lenvatinib-based therapies show promising treatment outcomes for patients with unresectable hepatocellular carcinoma (uHCC). However, the effect and safety of Lenvatinib-based therapies still need to be further studies.

Methods

This was a retrospective, single-center study on the safety and treatment efficacy of Lenvatinib-based combination therapies for uHCC Patients. The primary endpoints were progression-free survival (PFS) and overall survival (OS). The secondary endpoints were progressive disease (PD), stable disease (SD), partial response (PR), and complete response (CR).

Results

Of 91 patients, there were 16 females and 75 males with uHCC who received systemic therapies based on Lenvatinib in our center. Forty-six patients (50.5%) received Lenvatinib combined with PD-1 antibody treatment. All these patients also received local therapy with the exception of 2 patients. The remaining 36 patinets received Lenvatinib combined with transcatheter arterial chemoembolization (TACE), 1 patient treated Lenvatinib combined with radiotherapy, 8 patients received Lenvatinib alone. At a median treatment time of 8 months, the objective response rate (ORR) of the entire cohort was 58.2% (53 patients), including 7 patients with CR and 46 patients with PR. 21 patients (23.1%) had SD. The disease control rate (DCR) of all patients was 81.3% (74 patients). However, 17 patients (18.7%) developed PD. The 1- and 2-year cumulative OS rates for the entire cohort were 66.8% and 39.3%, while the corresponding PFS rates were 38.0% and 17.1%, respectively. Univariate and multivariate Cox regression analysis revealed multiple tumor sites to be an independent OS risk factor for uHCC patients (HR=2.204, 95% CI=1.104-4.399, P=0.025). The most frequently reported adverse events in all patients were AST elevation (51.6%), followed by hypertension (33.0%), ALT elevation (26.4%), and decreased appetite (25.3%). After a combination treatment of Lenvatinib-based therapies, 15 patients met the criteria for salvage liver resection and underwent down-staging hepatectomy with a curative intent. The combination of PD-1 treatment was not very effective in improving the prognosis of uHCC patients treated with Lenvatinib combined with TACE.

Conclusion

Our study demonstrated that a proportive of patients benefited from Lenvatinib-based combination therapies with manageable safety profiles, allowing these patients to undergo downstaging surgery with curative intent.

Hepatocellular carcinoma (HCC) immunotherapy by anti-PD-1 monoclonal antibodies: A rapidly evolving strategy

Hepatocellular carcinoma (HCC) is one of the deadliest cancers in the world, with a high relapse rate. Delayed symptom onset observed in 70-80% of patients leads to diagnosis in advanced stages commonly associated with chronic liver disease. Programmed cell death protein 1 (PD-1) blockade therapy has recently emerged as a promising therapeutic option in the clinical management of several advanced malignancies, including HCC, due to the activation of exhausted tumor-infiltrating lymphocytes and improved outcomes of T-cell function. However, many people with HCC do not respond to PD-1 blockade therapy, and the diversity of immune-related adverse events (irAEs) restricts their clinical utility. Therefore, numerous effective combinatory strategies, including combinations with anti-PD-1 antibodies and other therapeutic methods ranging from chemotherapy to targeted therapies, are evolving to improve therapeutic outcomes and evoke synergistic anti-tumor impressions in patients with advanced HCC. Unfortunately, combined therapy may have more side effects than single-agent treatment. Nonetheless, identifying appropriate predictive biomarkers can aid in managing potential immune-related adverse events by distinguishing patients who respond best to PD-1 inhibitors as single agents or in combination strategies. In the present review, we summarize the therapeutic potential of PD-1 blockade therapy for advanced HCC patients. Besides, a glimpse of the pivotal predictive biomarkers influencing a patient's response to anti-PD-1 antibodies will be provided.

Interventional Oncology and Immuno-Oncology: Current Challenges and Future Trends

Personalized cancer treatments help to deliver tailored and biologically driven therapies for cancer patients. Interventional oncology techniques are able to treat malignancies in a locoregional fashion, with a variety of mechanisms of action leading to tumor necrosis. Tumor destruction determines a great availability of tumor antigens that can be recognized by the immune system, potentially triggering an immune response. The advent of immunotherapy in cancer care, with the introduction of specific immune checkpoint inhibitors, has led to the investigation of the synergy of these drugs when used in combination with interventional oncology treatments. The aim of this paper is to review the most recent advances in the field of interventional oncology locoregional treatments and their interactions with immunotherapy.

Correlation of serum chemokine 14 with Barcelona Clinic Liver Cancer Stage, Lymphocyte Profile, and Response to Transarterial Chemoembolization in Patients with Hepatocellular Carcinoma

PURPOSE

To investigate the clinical relevance of serum chemokine 14 (sCCL14) in patients with hepatocellular carcinoma (HCC) and the effect of transarterial chemoembolization (TACE) on the expression level of sCCL14 and the immune microenvironment.

MATERIALS AND METHODS

In this prospective single-center observational study, 52 patients with HCC were recruited from January 2019 to December 2021, their clinical data and blood samples were collected, and the relationship between sCCL14 and progression-free survival (PFS) and TACE treatment response was analyzed.

RESULTS

Among the 52 patients with HCC (Barcelona Clinic Liver Cancer [BCLC] Stage A, 25.0%; BCLC Stage B, 44.2%; and BCLC Stage C, 30.8%), patients with BCLC Stage C HCC had significantly lower sCCL14 levels than those of patients with BCLC Stages A and B HCC (P = .001). sCCL14 levels were significantly higher in the first week after treatment than before TACE treatment (P = .024). Baseline sCCL14 levels in patients who showed complete response after TACE treatment were significantly higher than those in other groups, and lower baseline sCCL14 values were associated with shorter PFS times. Multivariate Cox regression analysis showed that sCCL14 level (hazard ratio, 1.855; 95% CI, 1.039-3.311; P = .037) was an independent prognostic factor of PFS. sCCL14 levels negatively correlated with the proportion of B lymphocytes and regulatory T cells in circulating blood and positively correlated with the absolute T-lymphocyte count.

CONCLUSIONS

sCCL14 may be a predictive biomarker of TACE effectiveness. Further studies are needed to validate and outline the role of combination immunotherapy.

Combined Loco-Regional and Systemic Treatment Strategies for Hepatocellular Carcinoma: From Basics to New Developments

Recent advances in systemic therapeutic options have led to improved survival in patients with advanced hepatocellular carcinoma. In order to optimize patient outcomes across different disease stages, attempts are being made at exploiting combinations of loco-regional treatments and systemic therapeutic regimens. The possibilities of a beneficial synergistic effect are strongly supported by biological evidence of changes in tumor microenvironment and systemic immunity. With the advent of newer interventional technologies and newer biological and immunological drugs, these possibilities keep on gaining interest and expectations, yet many questions remain unanswered as to how to best manipulate and combine the two therapeutic approaches.This review aims at providing a general overview of biological foundations, preliminary clinical applications, critical issues and future directions of this constantly growing field.

What’s next for cancer vaccines

Cancer vaccines have been shown clinically to drive tumor-reactive cell activation, proliferation, and effector function. Unfortunately, tumor eradication by treatment with cancer vaccines has been unsuccessful in many patients. Critical steps are under way to improve vaccine efficacy and combine them with immunotherapy and standard-of-care treatments.

Synergizing liver systemic treatments with interventional oncology: friend or foe?

Interventional radiology techniques provide excellent local tumor control for small tumors in various organs, but several limitations can hamper the oncological outcomes such as the tumor size or the number of lesions. Technical improvements, optimal patient selection and combination with systemic therapies, including immune checkpoint inhibitors, have been successfully developed to overcome these barriers.In this setting, chemotherapy and targeted therapies aim to diminish the tumor burden in addition to local treatments, while immunotherapies may have a synergistic effect in terms of mechanism of action on the tumor cell as well as the immune environment, with multiple treatment combinations being available. Finally, interventional Rrdiology treatments often increase tumor antigen exposure to the immune system, and thus stimulate a specific antitumor immune response that can act beyond the treated site. Notwithstanding their many benefits, combination treatment may also result in complications, the most feared may be auto-immune-related adverse events.In early studies, several combined therapies have shown promising levels of safety and efficacy, particularly in hepatocellular carcinoma.This review provides a comprehensive and up-to-date overview of results of combined therapies for primary and secondary liver malignancies. Recent advances and future perspectives will be discussed.

Efficacy and safety of transarterial chemoembolization combining sorafenib with or without immune checkpoint inhibitors in previously treated patients with advanced hepatocellular carcinoma: A propensity score matching analysis

Purpose

To compare the efficacy and safety of transarterial chemoembolization (TACE) plus sorafenib and immune checkpoint inhibitors (T+S+ICIs) and TACE plus sorafenib (T+S) when treating patients with advanced hepatocellular carcinoma (HCC) who have previously received locoregional treatment.

Materials and methods

A retrospective analysis was performed on the patients with Barcelona Clinic Liver Cancer (BCLC) stage C HCC from May 2019 to December 2020. These patients were treated with locoregional therapy and showed radiographic progression after the treatment. Patients received either T+S+ICIs or T+S. The outcomes, including disease control rate (DCR), progression-free survival (PFS), overall survival (OS), and safety, were compared. The propensity score matching (PSM) methodology was used to reduce the influence of confounding factors on the outcomes.

Results

Forty-three patients were included in the T+S group and 33 in the T+S+ICI group. After PSM (n = 29 in each group), patients who received T+S+ICIs had a higher DCR (82.8% vs. 58.6%, p = 0.043), longer median PFS (6.9 vs. 3.8 months, p = 0.003), and longer median OS (12.3 vs. 6.3 months, p = 0.008) than those who underwent T+S. Eastern Cooperative Oncology Group performance status was an independent predictor of PFS, and age was an independent predictor of OS. The incidence of treatment-related adverse events in T+S+ICIs was well controlled.

Conclusions

Compared with TACE combined with sorafenib, TACE combined with sorafenib plus ICIs is a potentially safe and effective treatment regimen for patients with advanced HCC who previously received locoregional treatment.

Impact and Novel Perspective of Immune Checkpoint Inhibitors in Patients with Early and Intermediate Stage HCC

Surgery and radiofrequency ablation remain the gold standard to achieve cure in patients with hepatocellular carcinoma (HCC). After a decade in which only sorafenib was available for advanced and metastatic HCC, the emergence of other molecularly targeted drugs and immune checkpoint inhibitors (ICIs) has significantly improved the patients` prognosis. In particular, the use of ICIs has shown promising results and has revolutionized the treatment algorithm in HCC patients. Indeed, preclinical and clinical data have documented a high density of immunosuppressive cells and an increased expression of the programmed death-1 (PD-1) receptor and cytotoxic T-cell associated protein-4 (CTLA-4) in HCC. However, despite these observations, no validated biomarker is available and the molecular groundwork responsible for response to ICIs remains elusive. The anti-CTLA4 monoclonal antibody tremelimumab and the anti-PD-1 monoclonal antibodies nivolumab and pembrolizumab were the first ICIs to be tested in HCC. Recently, the combination of the anti-programmed death-ligand 1 (PD-L1) inhibitor atezolizumab and the anti-vascular endothelial growth factor (VEGF) antibody bevacizumab demonstrated an improvement in patient outcome compared to sorafenib, becoming the standard of care in the frontline setting of advanced disease. Other immunotherapeutic agents such as pembrolizumab or the combination nivolumab-ipilimumab have shown promising results that have to be confirmed in phase III studies. Currently, the combination of different ICIs (i.e., ipilimumab, durvalumab) and anti-angiogenic agents (i.e., regorafenib, lenvatinib) is currently being tested in several trials and will hopefully revolutionize the treatment of HCC. To date, numerous studies are underway evaluating ICIs in adjuvant and neoadjuvant settings to improve survival in early and intermediate stages. Thus, this review focuses on the rationale for ICIs and their potential use for early or intermediate HCC stages.

Immune Checkpoint Inhibitors for Advanced Hepatocellular Carcinoma: Monotherapies and Combined Therapies

Hepatocellular carcinoma (HCC) is an important cause of cancer death and is considered the 3rd most lethal around the world. Hepatectomy, liver transplantation, and ablation therapy are considered curative treatments for early-stage HCC. Transarterial chemoembolization is the preferred therapy for intermediate stage HCC. Ssystemic therapy is recommended for advanced HCC. For more than a decade, sorafenib and lenvatinib were used as the first-line treatment for the advanced HCC. For the great success of immunotherapy in melanoma and lung cancer, some immune-based treatments, such as immune checkpoint inhibitors (ICIs), have been applied in the treatment of HCC. The anti-programmed cell death protein 1 (PD1) antibodies, including nivolumab and pembrolizumab, have been approved by the Food and Drug Administration for sorafenib-pretreated patients. Moreover, due to the results of durable antitumor responses attained from the phase 3 trials, atezolizumab in combination with bevacizumab is now the standard therapy for advanced HCC. Recently, there are a lot of clinical trials involving the ICIs, as monotherapy or combination therapy, with tyrosine kinase inhibitors, antiangiogenic drugs, cytotoxic agents, and locoregional treatments, providing a promising outcome for advanced HCC. Thus, this review summarized the role of ICIs for HCC patients with monotherapy or combination therapy. The success and failures of monotherapy and combination therapy involving ICIs have provided advanced insights into HCC treatment and led to novel avenues to improve therapy efficacy in HCC.

Efficacy and Safety of TACE Combined With Lenvatinib Plus PD-1 Inhibitors Compared With TACE Alone for Unresectable Hepatocellular Carcinoma Patients: A Prospective Cohort Study

Purpose

To compare the efficacy and safety of the combination of transcatheter arterial chemoembolization (TACE), Lenvatinib, and programmed cell death protein-1 (PD-1) inhibitors (combination group) with TACE (TACE group) in the treatment of patients with unresectable hepatocellular carcinoma (uHCC).

Methods

We consecutively enrolled 110 patients with uHCC in this prospective cohort study, with 56 patients receiving combination treatment and 54 patients receiving TACE from November 2017 to September 2020. The differences in tumor response, survival benefit, and adverse events (AEs) were compared between the two groups. Factors affecting survival were identified via Cox regression analysis.

Results

Compared with the TACE group, the combination group had a higher objective response rate (ORR) (67.9% vs. 29.6%, p < 0.001), longer median progression-free survival (mPFS) (11.9 vs. 6.9 months, P = 0.003) and overall survival (mOS) (23.9 vs. 15.3 months, p < 0.001). Multivariate analysis showed that the neutrophil-to-lymphocyte ratio (NLR) and the treatment option were independent factors associated with the PFS and OS. Further subgroup analysis showed that patients with low NLR (≤median 3.11) receiving combination therapy had better mPFS (20.1 vs. 6.2 months, P < 0.001) and mOS (28.9 vs. 15.2 months, P < 0.001) than those receiving TACE, while no obvious difference in PFS or OS was observed between the two groups in patients with high NLR (> 3.11). There were no unexpected toxicities in the combination group.

Conclusion

Compared with TACE, the combination treatment demonstrated an improved clinical efficacy and manageable safety profile in patients with uHCC. Combination treatment showed better therapeutic efficacy in patients with low NLR; therefore, this ratio could be used to identify patients who will benefit from this treatment.

Comparison of metabolic and immunologic responses to transarterial chemoembolization with different chemoembolic regimens in a rabbit VX2 liver tumor model

OBJECTIVES

The goal of this study was to investigate the effects of TACE using Lipiodol, Oncozene™ drug-eluting embolics (DEEs), or LUMI™-DEEs alone, or combined with bicarbonate on the metabolic and immunological tumor microenvironment in a rabbit VX2 tumor model.

METHODS

VX2 liver tumor-bearing rabbits were assigned to five groups. MRI and extracellular pH (pHe) mapping using Biosensor Imaging of Redundant Deviation in Shifts (BIRDS) were performed before and after intra-arterial therapy with conventional TACE (cTACE), DEE-TACE with Idarubicin-eluting Oncozene™-DEEs, or Doxorubicin-eluting LUMI™-DEEs, each with or without prior bicarbonate infusion, and in untreated rabbits or treated with intra-arterial bicarbonate only. Imaging results were validated with immunohistochemistry (IHC) staining of cell viability (PCNA, TUNEL) and immune response (HLA-DR, CD3). Statistical analysis was performed using Mann-Whitney U test.

RESULTS

pHe mapping revealed that combining cTACE with prior bicarbonate infusion significantly increased tumor pHe compared to control (p = 0.0175) and cTACE alone (p = 0.0025). IHC staining revealed peritumoral accumulation of HLA-DR+ antigen-presenting cells and CD3 + T-lymphocytes in controls. cTACE-treated tumors showed reduced immune infiltration, which was restored through combination with bicarbonate. DEE-TACE with Oncozene™-DEEs induced moderate intratumoral and marked peritumoral infiltration, which was slightly reduced with bicarbonate. Addition of bicarbonate prior to LUMI™-beads enhanced peritumoral immune cell infiltration compared to LUMI™-beads alone and resulted in the strongest intratumoral immune cell infiltration across all treated groups.

CONCLUSIONS

The choice of chemoembolic regimen for TACE strongly affects post-treatment TME pHe and the ability of immune cells to accumulate and infiltrate the tumor tissue.

KEY POINTS

• Combining conventional transarterial chemotherapy with prior bicarbonate infusion increases the pHe towards a more physiological value (p = 0.0025). • Peritumoral infiltration and intratumoral accumulation patterns of antigen-presenting cells and T-lymphocytes after transarterial chemotherapy were dependent on the choice of the chemoembolic regimen. • Combination of intra-arterial treatment with Doxorubicin-eluting LUMI™-beads and bicarbonate infusion resulted in the strongest intratumoral presence of immune cells (positivity index of 0.47 for HLADR+-cells and 0.62 for CD3+-cells).

Transarterial Embolization Modulates the Immune Response within Target and Nontarget Hepatocellular Carcinomas in a Rat Model

Background Transarterial embolization (TAE) is the most common treatment for hepatocellular carcinoma (HCC); however, there remain limited data describing the influence of TAE on the tumor immune microenvironment. Purpose To characterize TAE-induced modulation of the tumor immune microenvironment in a rat model of HCC and identify factors that modulate this response. Materials and Methods TAE was performed on autochthonous HCCs induced in rats with use of diethylnitrosamine. CD3, CD4, CD8, and FOXP3 lymphocytes, as well as programmed cell death protein ligand-1 (PD-L1) expression, were examined in three cohorts: tumors from rats that did not undergo embolization (control), embolized tumors (target), and nonembolized tumors from rats that had a different target tumor embolized (nontarget). Differences in immune cell recruitment associated with embolic agent type (tris-acryl gelatin microspheres [TAGM] vs hydrogel embolics) and vascular location were examined in rat and human tissues. A generalized estimating equation model and t, Mann-Whitney U, and χ2 tests were used to compare groups. Results Cirrhosis-induced alterations in CD8, CD4, and CD25/CD4 lymphocytes were partially normalized following TAE (CD8: 38.4%, CD4: 57.6%, and CD25/CD4: 21.1% in embolized liver vs 47.7% [P = .02], 47.0% [P = .01], and 34.9% [P = .03], respectively, in cirrhotic liver [36.1%, 59.6%, and 4.6% in normal liver]). Embolized tumors had a greater number of CD3, CD4, and CD8 tumor-infiltrating lymphocytes relative to controls (191.4 cells/mm2 vs 106.7 cells/mm2 [P = .03]; 127.8 cells/mm2 vs 53.8 cells/mm2 [P < .001]; and 131.4 cells/mm2 vs 78.3 cells/mm2 [P = .01]) as well as a higher PD-L1 expression score (4.1 au vs 1.9 au [P < .001]). A greater number of CD3, CD4, and CD8 lymphocytes were found near TAGM versus hydrogel embolics (4.1 vs 2.0 [P = .003]; 3.7 vs 2.0 [P = .01]; and 2.2 vs 1.1 [P = .03], respectively). The number of lymphocytes adjacent to embolics differed based on vascular location (17.9 extravascular CD68+ peri-TAGM cells vs 7.0 intravascular [P < .001]; 6.4 extravascular CD68+ peri-hydrogel embolic cells vs 3.4 intravascular [P < .001]). Conclusion Transarterial embolization-induced dynamic alterations of the tumor immune microenvironment are influenced by underlying liver disease, embolic agent type, and vascular location. © RSNA, 2022 Online supplemental material is available for this article. See also the editorials by Kennedy et al and by White in this issue.

Evaluation of immune-modulating drugs for use in drug-eluting microsphere transarterial embolization

Cancer immunotherapy has yet to reach its full potential due in part to limited response rates and side effects inherent to systemic delivery of immune-modulating drugs. Local administration of immunotherapy using drug-eluting embolic (DEE) microspheres as drug delivery vehicles for direct infusion into tumor-feeding arteries might increase and prolong tumor drug concentrations and reduce systemic drug exposure, potentially improving the risk-to-benefit ratio of these agents. The purpose of this study was to evaluate the ability of four immune modulators affecting two different immune pathways to potentiate replication of immune cells from a woodchuck model of hepatocellular carcinoma. DSR 6434, a Toll-like receptor agonist, and BMS-202, a PD-L1 checkpoint inhibitor, induced immune cell replication and were successfully loaded into radiopaque DEE microspheres in high concentrations. Release of DSR 6434 from the DEE microspheres was rapid (t99% = 0.4 h) upon submersion in a physiologic saline solution while BMS-202 demonstrated a more sustained release profile (t99% = 17.9 h). These findings demonstrate the feasibility of controlled delivery of immune-modulating drugs via a local DEE microsphere delivery paradigm.

Expanding the role of interventional oncology for advancing precision immunotherapy of solid tumors

Adoptive cell therapy with chimeric antigen receptors (CAR) T cells has proven effective for hematologic malignancies, but success in solid tumors has been impeded by poor intratumoral infiltration, exhaustion of effector cells from antigen burden, and an immunosuppressive tumor microenvironment. Results from recent clinical trials and preclinical studies lend promising evidence of locoregional approaches for CAR T cell delivery, priming the tumor microenvironment, and performing adjuvant therapies that sustain T cell activity. Interventional oncology is a subspeciality of interventional radiology where imaging guidance is used to perform percutaneous and catheter-directed procedures for localized, non-surgical therapy or interrogation of solid tumors. Interventional oncology provides unique synergies with immunotherapy, which has been well-studied to improve treatment efficacy while reducing toxicities associated with systemic treatment. Besides aiding in CAR T cell delivery, priming, or the stimulation of the tumor microenvironment to promote effector survival and function, interventional oncology can also aid in the monitoring of treatment response through selective, multiplex tumor sampling and catheter-based venous sampling. This review presents an overview of interventional oncology, its various procedures, and its potential for advancing CAR T cell immunotherapy of solid tumors.

The influence of transarterial chemoembolization on serum levels of soluble programed cell death ligand-1 in advanced hepatocellular carcinoma patients

AIMS

To investigate the implications of soluble programmed cell death-ligand 1 (sPD-L1) in hepatocellular carcinoma (HCC) patients treated with transarterial chemoembolization (TACE) and to evaluate the potential value of sPD-L1 to guide selection of the optimal time to begin combination therapy with TACE and immune checkpoint inhibitors (ICIs).

MATERIALS AND METHODS

Thirty-one HCC patients suitable for TACE and 55 healthy volunteers were enrolled in this study. Three milliliters of peripheral venous blood of patients were collected on 1 day before TACE and 3, 7, and 30 days after TACE respectively for assay of sPD-L1 using enzyme-linked immunosorbent assay. The associations of the sPD-L1 level with the clinical features, outcomes, and the fluctuation of sPD-L1 during the treatment were analyzed.

RESULTS

The initial sPD-L1 level of patients was significantly higher than that of the control group. And it was significantly associated with BCLC stage, portal venous invasion, tumor size, and number of foci. The sPD-L1 levels of 3 and 7 days after TACE were both significantly higher than the initial level. And that of 30 days after TACE was lower than the initial level, but the difference was not statistically significant. There was no significant difference of sPD-L1 level after embolization with embolic beads of different size. The level of sPD-L1 of CR patients was lower than that of PR, SD patients, but the differences were not significant.

CONCLUSION

The level of sPD-L1 was associated with tumor aggressiveness and outcomes, suggesting its role as a possible predictive biomarker. The increases in sPD-L1 after TACE suggests that combined treatment with TACE and ICIs may be a promising therapeutic strategy in HCC. One week after TACE might be a suitable time to begin the administration of immunotherapy.

Immunomodulation for hepatocellular carcinoma therapy: current challenges

PURPOSE OF REVIEW

The emergence of novel immunotherapies, such as immune-checkpoint inhibitors has changed the landscape of systemic cancer treatment. In hepatocellular carcinoma (HCC) patients, despite initial enthusiasm, the proportion of responders to immune-checkpoint inhibitors remains low. We provide a brief update of this rapidly evolving field, with specific focus on the development in the field of predictive factors and the immunomodulation induced by locoregional therapies.

RECENT FINDINGS

Even if the immune contexture of HCC before the treatment remains the most promising predictive marker for response to immunotherapies, recent findings show that the cause of HCC may have also a key role. Specific inflammatory mechanisms induced by NASH may result in limited efficacy of immunotherapy compared with viral HCC. Other recent findings showed that percutaneous ablations are responsible for intratumoral immune changes and systemic immune system activation that may help to prevent recurrence when combined with immunotherapies. In case of multifocal HCC, transarterial therapies (TACE and SIRT) may help to turn a cold tumor type to a hot tumor type and could be associated with immune-checkpoint inhibitors to improve outcomes.

SUMMARY

The future HCC management will focus on patient stratification for specific immunotherapies depending on the signature and cause of HCC and the best combined approaches in which locoregional therapies may play a pivotal role.

Differential Virus-Specific IFN-Gamma Producing T Cell Responses to Marek's Disease Virus in Chickens With B19 and B21 MHC Haplotypes

Marek’s disease virus (MDV), the etiologic agent for Marek’s disease (MD), causes a deadly lymphoproliferative disease in chickens. Causes of the well-documented association between genetically defined lines of chicken and resistance to MD remain unknown. Here, the frequencies of IFN-gamma producing pp38 and MEQ-specific T cell responses were determined in line N (B21 haplotype; MD-resistant) and line P2a (B19 haplotype, MD-susceptible) chickens after infection with vaccine and/or virulent (RB1B) strains of MDV using both standard ex vivo and cultured chIFN-gamma ELISPOT assays. Notably, MDV infection of naïve and vaccinated MD-resistant chickens induced higher frequencies of IFN-gamma producing MDV-specific T cell responses using the cultured and ex vivo ELISPOT assay, respectively. Remarkably, vaccination did not induce or boost MEQ-specific effector T cells in the susceptible chickens, while it boosted both pp38-and MEQ-specific response in resistant line. Taken together, our results revealed that there is a direct association between the magnitude of T cell responses to pp38 and MEQ of MDV antigens and resistance to the disease.

Current Perspectives on the Immunosuppressive Niche and Role of Fibrosis in Hepatocellular Carcinoma and the Development of Antitumor Immunity

Immune checkpoint inhibitors have become the mainstay of treatment for hepatocellular carcinoma (HCC). However, they are ineffective in some cases. Previous studies have reported that genetic alterations in oncogenic pathways such as Wnt/β-catenin are the important triggers in HCC for primary refractoriness. T-cell exhaustion has been reported in various tumors and is likely to play a prominent role in the emergence of HCC due to chronic inflammation and cirrhosis-associated immune dysfunction. Immunosuppressive cells including regulatory T-cells and tumor-associated macrophages infiltrating the tumor are associated with hyperprogressive disease in the early stages of immune checkpoint inhibitor treatment. In addition, stellate cells and tumor-associated fibroblasts create an abundant desmoplastic environment by producing extracellular matrix. This strongly contributes to epithelial to mesenchymal transition via signaling activities including transforming growth factor beta, Wnt/β-catenin, and Hippo pathway. The abundant desmoplastic environment has been demonstrated in pancreatic ductal adenocarcinoma and cholangiocarcinoma to suppress cytotoxic T-cell infiltration, PD-L1 expression, and neoantigen expression, resulting in a highly immunosuppressive niche. It is possible that a similar immunosuppressive environment is created in HCC with advanced fibrosis in the background liver. Although sufficient understanding is required for the establishment of immune therapies of HCC, further investigations are still required in this field.

Advances in locoregional therapy for hepatocellular carcinoma combined with immunotherapy and targeted therapy

Locoregional therapies (LRTs) of hepatocellular carcinoma (HCC) represented by ablation and TACE has become the main means for the clinical treatment of unresectable HCC. Among these, TACE is used throughout the stage Ib to IIIb of HCC treatment. In recent years, immunotherapy led by immune checkpoint inhibitors has become a hot direction in clinical research. At the same time, targeted drugs such as Sorafenib and Apatinib have played an important role in the treatment and complementary therapy of advanced HCC, and their clinical application has been quite mature. HCC is the sixth most common malignant tumor in the world. When it comes to its treatment, different therapies have different indications, and their individual efficacies are not satisfactory, which makes the exploration of the use of combination therapy in HCC treatment become a new trend. In this paper, the status of the three therapies and the progress of their combined application are briefly reviewed.

PD-1 expression in hepatocellular carcinoma predicts liver-directed therapy response and bridge-to-transplant survival

BACKGROUND

Hepatocellular carcinoma (HCC) patients undergo liver-directed therapy (LDT) to control tumor burden while awaiting liver transplantation with response impacting waitlist survival. In this study, we investigate the link between absolute lymphocyte count (ALC) and PD-1 expression with response to LDT and bridge-to-transplant survival.

METHODS

Treatment-naïve HCC patients (n = 86) undergoing LDT were enrolled at a single center from August 2016-March 2020. Response to LDT was determined using mRECIST. Blood samples were collected on the day of LDT and at follow-up. Cells were analyzed for phenotype by flow cytometry. Outcomes were liver transplantation or tumor progression.

RESULTS

Incomplete response to initial LDT was associated with tumor progression precluding liver transplantation (OR: 7.6, 1.7 - 33.3, P < 0.001). Univariate analysis of baseline T cell phenotypes revealed ALC (OR: 0.44, 0.24-0.85, P = 0.009) as well as intermediate expression of PD-1 on CD4 (OR: 3.3, 1.03-10.3, P = 0.034) and CD8 T cells (OR: 3.0, 0.99-8.8 P = 0.043) associated with incomplete response to LDT. Elevations in PD-1 expression were associated with increased risk of bridge-to-transplant tumor progression (HR: 3.2, 1.2-9.4). In patients successfully bridged to liver transplantation, pre-treatment peripheral PD-1 profile was associated with advanced tumor staging (P < 0.005) with 2/4 of patients with elevations in PD-1 having T3-T4 TNM staging compared to 0 with low PD-1 expression.

CONCLUSION

Low lymphocyte count or elevated expression of the PD-1 checkpoint inhibitor is associated with incomplete response to LDT and increased risk of bridge-to-transplant tumor progression. Patients with impaired T cell homeostasis may benefit from PD-1 immunotherapy to improve response to LDT and improve bridge-to-transplant outcomes.

Current Landscape and Future Directions of Biomarkers for Immunotherapy in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common liver cancer and one of the leading causes of cancer-related deaths in the world. Multiple immunotherapeutic approaches have been investigated to date, and immunotherapy has become the new standard of care therapy in HCC. However, the current role of immunotherapy in HCC remains non-curative. Given this context, a high priority for oncology is understanding the biomarkers that predict clinical response to immunotherapy, have the potential to improve patient selection to maximize the clinical benefit, and spare unnecessary toxicity. In this review, we summarize the key predictive and prognostic biomarkers investigated in immunotherapy clinical trials in HCC and the emerging biomarkers to serve as a roadmap for future clinical trials. Biomarkers from tumoral tissues including PDL-1 expression, tissue infiltrating lymphocytes, tumor mutational burden (TMB) and specific immune signatures, and from peripheral blood including neutrophil-to-lymphocytes ratio, platelet-to-lymphocytes ratio, circulating tumor DNA (ctDNA), circulating tumor cells (CTCs), and specific cytokines, along with gut microbiota are among the studied biomarkers to date in the HCC era. More integrative approaches, including mathematical biomarkers to predict immunotherapy outcomes, are yet to be studied in HCC.

Immune Responses Following Locoregional Treatment for Hepatocellular Carcinoma: Possible Roles of Adjuvant Immunotherapy

Hepatocellular carcinoma (HCC) is a common cause of cancer-related deaths worldwide. Unlike other types of cancer, HCC can be treated with locoregional treatments (LRTs) such as radiofrequency ablation (RFA) or transarterial chemoembolization (TACE). However, recurrences following LRTs are common, and strategies to improve long-term outcomes need to be developed. The exhaustion of anti-tumor immunity in HCC has been well established in many reports and the immunomodulatory effects of LRTs (enhancement of tumor antigen-specific T cell responses after RFA, reduction of effector regulatory T cells after TACE) have also been reported in several previous studies. However, a comprehensive review of previous studies and the possible roles of immunotherapy following LRTs in HCC are not known. In this review, we discuss the immunological evidence of current clinical trials using LRTs and combined immunotherapies, and the possible role of this strategy.

Society for Immunotherapy of Cancer (SITC) clinical practice guideline on immunotherapy for the treatment of hepatocellular carcinoma

Patients with advanced hepatocellular carcinoma (HCC) have historically had few options and faced extremely poor prognoses if their disease progressed after standard-of-care tyrosine kinase inhibitors (TKIs). Recently, the standard of care for HCC has been transformed as a combination of the immune checkpoint inhibitor (ICI) atezolizumab plus the anti-vascular endothelial growth factor (VEGF) antibody bevacizumab was shown to offer improved overall survival in the first-line setting. Immunotherapy has demonstrated safety and efficacy in later lines of therapy as well, and ongoing trials are investigating novel combinations of ICIs and TKIs, in addition to interventions earlier in the course of disease or in combination with liver-directed therapies. Because HCC usually develops against a background of cirrhosis, immunotherapy for liver tumors is complex and oncologists need to account for both immunological and hepatological considerations when developing a treatment plan for their patients. To provide guidance to the oncology community on important concerns for the immunotherapeutic care of HCC, the Society for Immunotherapy of Cancer (SITC) convened a multidisciplinary panel of experts to develop a clinical practice guideline (CPG). The expert panel drew on the published literature as well as their clinical experience to develop recommendations for healthcare professionals on these important aspects of immunotherapeutic treatment for HCC, including diagnosis and staging, treatment planning, immune-related adverse events (irAEs), and patient quality of life (QOL) considerations. The evidence- and consensus-based recommendations in this CPG are intended to give guidance to cancer care providers treating patients with HCC.

Treatment of Hepatocellular Carcinoma with Immune Checkpoint Inhibitors and Applicability of First-Line Atezolizumab/Bevacizumab in a Real-Life Setting

Immune checkpoint inhibitors (ICIs) are the new frontier for the treatment of advanced hepatocellular carcinoma (HCC). Since the first trial with tremelimumab, a cytotoxic T-lymphocyte-associated protein 4 inhibitor, increasing evidence has confirmed that these drugs can significantly extend the survival of patients with advanced hepatocellular carcinoma (HCC). As a matter of fact, the overall survival and objective response rates reported in patients with advanced HCC treated with ICIs are the highest ever reported in the second-line setting and, most recently, the combination of the anti-programmed death ligand protein-1 atezolizumab with bevacizumab-an anti-vascular endothelial growth factor monoclonal antibody-demonstrated superiority to sorafenib in a Phase III randomized clinical trial. Therefore, this regimen has been approved in several countries as first-line treatment for advanced HCC and is soon expected to be widely used in clinical practice. However, despite the promising results of trials exploring ICIs alone or in combination with other agents, there are still some critical issues to deal with to optimize the prognosis of advanced HCC patients. For instance, the actual proportion of patients who are deemed eligible for ICIs in the real-life ranges from 10% to 20% in the first-line setting, and is even lower in the second-line scenario. Moreover, long-term data regarding the safety of ICIs in the population of patients with cirrhosis and impaired liver function are lacking. Lastly, no biomarkers have been identified to predict response, and thus to help clinicians to individually tailor treatment. This review aimed to summarize the state of the art immunotherapy in HCC and, by analyzing a large, multicenter cohort of Italian patients with HCC, to assess the potential applicability of the combination of atezolizumab/bevacizumab in the real-life setting.

Combined with interventional therapy, immunotherapy can create a new outlook for tumor treatment

Recent progress in immunotherapy provides hope of a complete cure to cancer patients. However, recent studies have reported that only a limited number of cancer patients with a specific immune status, known as "cold tumor", can benefit from a single immune agent. Although the combination of immune agents with different mechanisms can partially increase the low response rate and improve efficacy, it can also result in more side effects. Therefore, discovering therapies that can improve tumors' response rate to immunotherapy without increasing toxicity for patients is urgently needed. Tumor interventional therapy is promising. It mainly includes transcatheter arterial chemoembolization, ablation, radioactive particle internal irradiation, and photodynamic interventional therapy based on a luminal stent. Interventional therapy can directly kill tumor cells by targeted drug delivery in situ, thus reducing drug dosage and systemic toxicity like cytokine release syndrome. More importantly, interventional therapy can regulate the immune system through numerous mechanisms, making it a suitable choice for immunotherapy to combine with. In this review, we provide a brief description of immunotherapies (and their side effects) on tumors of different immune types and preliminarily elaborate on interventional therapy mechanisms to improve immune efficacy. We also discuss the progress and challenges of the combination of interventional therapy and immunotherapy.

Locoregional therapies in the era of molecular and immune treatments for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-related mortality and has an increasing incidence worldwide. Locoregional therapies, defined as imaging-guided liver tumour-directed procedures, play a leading part in the management of 50-60% of HCCs. Radiofrequency is the mainstay for local ablation at early stages and transarterial chemoembolization (TACE) remains the standard treatment for intermediate-stage HCC. Other local ablative techniques (microwave ablation, cryoablation and irreversible electroporation) or locoregional therapies (for example, radioembolization and sterotactic body radiation therapy) have been explored, but have not yet modified the standard therapies established decades ago. This understanding is currently changing, and several drugs have been approved for the management of advanced HCC. Molecular therapies dominate the adjuvant trials after curative therapies and combination strategies with TACE for intermediate stages. The rationale for these combinations is sound. Local therapies induce antigen and proinflammatory cytokine release, whereas VEGF inhibitors and tyrosine kinase inhibitors boost immunity and prime tumours for checkpoint inhibition. In this Review, we analyse data from randomized and uncontrolled studies reported with ablative and locoregional techniques and examine the expected effects of combinations with systemic treatments. We also discuss trial design and benchmarks to be used as a reference for future investigations in the dawn of a promising new era for HCC treatment.

Safety and Efficacy of Degradable Starch Microspheres Transcatheter Arterial Chemoembolization as a Bridging Therapy in Patients with Early Stage Hepatocellular Carcinoma and Child-Pugh Stage B Eligible for Liver Transplant

In patients with early-stage hepatocellular carcinoma, awaiting liver transplantation, current guidelines by AASLD and ESMO recommend a bridging therapy with a loco-regional treatment to prevent progression outside transplantation criteria. The standard of care in delaying disease progression has been recognized to be the transarterial chemoembolization. Permanent occlusion of tumor feeding vessels has effects on tumour stromal microenvironment by inducing intra- and intercellular signaling processes counteracting hypoxia, such as the release of vascular endothelial growth factor, a promoter of neoangiogenesis, tumour proliferation and metastatic growth. Among chemoembolization interventions, TACE with degradable starch microspheres represents an alternative to conventional cTACE and DEB-TACE and it minimizes detrimental effects on tumour stromal microenvironment, guaranteeing a transient occlusion of tumour feeding arteries and avoiding VEGF overexpression.Between January 2015 and September 2020, 54 consecutive patients with early-stage hepatocellular carcinoma and Child-Pugh stage B, who had undergone DSM-TACE as a bridging therapy while awaiting liver transplantation, were eligible for the study. A total of 154 DSM-TACE was performed, with a mean number of 2.85 procedures per patient. 18 patients (33.3%) succeeded in achieving liver transplantation, with a mean waiting time-to-transplantation of 11.7 months. The cumulative rates of patients still active on the WL at 6 months were about 91 and 93% when considering overall drop-out and tumour-specific drop-out respectively. Overall survival was about 96% at 6 months and 92% at 12 months. 17 patients experienced adverse events after the chemoembolizations. For patients with HCC in the transplant waiting list and within the Child-Pugh B stage, life expectancy may be dominated by the liver dysfunction, rather than by the tumour progression itself. In this population subset, the choice of LRT is critical because LRT itself could become a dangerous tool that is likely to precipitate liver dysfunction to an extent that survival is shortened rather than prolonged. Hence, the current study demonstrates that DSM-TACE is not far from being an ideal LRT, because it has an excellent safety profile, maintaining an efficacy that guarantees a clear advantage on the dropout rate with respect to the non-operative strategy, thus justifying its use.

Immunotherapy of hepatocellular carcinoma: Unique challenges and clinical opportunities

Current therapies for advanced hepatocellular carcinoma (HCC) are marginally effective and exacerbate underlying liver disease. The ability of immunotherapy to elicit nontoxic, systemic, long-lived anti-tumor activity makes it particularly well-suited for use in the setting of HCC. While therapeutic benefit has been achieved in early clinical trials, the efficacy of immune-based therapies is limited by several unique properties of HCC, most notably the inherently tolerogenic character of the liver in both healthy and diseased (chronically-infected or tumor-bearing) states. Therapeutic regimens that both counteract these immunosuppressive mechanisms and amplify tumor-specific immunity are expected to profoundly improve clinical outcomes for HCC patients.

Immunotherapy of hepatocellular carcinoma: Unique challenges and clinical opportunities

Current therapies for advanced hepatocellular carcinoma (HCC) are marginally effective and exacerbate underlying liver disease. The ability of immunotherapy to elicit nontoxic, systemic, long-lived anti-tumor activity makes it particularly well-suited for use in the setting of HCC. While therapeutic benefit has been achieved in early clinical trials, the efficacy of immune-based therapies is limited by several unique properties of HCC, most notably the inherently tolerogenic character of the liver in both healthy and diseased (chronically-infected or tumor-bearing) states. Therapeutic regimens that both counteract these immunosuppressive mechanisms and amplify tumor-specific immunity are expected to profoundly improve clinical outcomes for HCC patients.

Optimizing the Combination of Immunotherapy and Trans-Arterial Locoregional Therapy for Stages B and C Hepatocellular Cancer

Hepatocellular carcinoma (HCC), the most common primary hepatic malignancy worldwide, is the second leading cause of cancer-related death. Underlying liver dysfunction and advanced stage of disease require treatments to be optimally timed and implemented to minimize hepatic parenchymal damage while maximizing disease response and quality of life. Locoregional therapies (LRTs) such as trans-arterial chemo- and radio-embolization remain effective for intermediate liver-only and advanced HCC disease (i.e., Barcelona-Clinic liver cancer stages B and C) not amendable to primary resection or ablation. Additionally, these minimally invasive interventions have been shown to augment the immune system. This and the recent success of immune-oncologic treatments for HCC have generated interest in applying these therapies in combination with such locoregional interventions to improve patient outcomes and response rates. This report reviews the use of trans-arterial LRTs with immunotherapy for stages B and C HCC, potential biomarkers, and imaging methods for assessing the response and safety of such combinations.

Radiofrequency ablation and stereotactic body radiotherapy for hepatocellular carcinoma: should they clash or reconcile?

Until a few decades ago, surgical resection was the only valid option for treating hepatocellular carcinoma (HCC). However, various locoregional modalities including arterial-directed therapy, radiofrequency ablation (RFA), and radiotherapy have been recently shown to be effective. RFA is now established as a standard treatment for small localized HCCs, showing oncological results comparable to those of surgical resection in randomized studies. Stereotactic body radiotherapy (SBRT) is a modern radiotherapeutic modality that targets tumors with precision and delivers high radiation doses over a short period of time; it has particularly attracted clinical interest after its therapeutic efficacy was found to be similar to that of surgery in early-stage lung cancer. Given its potent disease control capability, SBRT has also been applied to early HCCs and demonstrated promising results in recent studies. It has also been noted for its suitability to treat tumors located in anatomical locations where RFA would be challenging. However, since its effectiveness has not been compared to that of RFA in randomized studies of patients eligible for RFA, the use of SBRT has been debated. This review was conducted to guide physicians from all fields involved in the treatment of early HCC. The therapeutic characteristics and indications of both SBRT and RFA are described, and recent comparative studies between the two modalities are discussed. In addition, we examined the factors that should be considered when selecting the appropriate treatments, and offer our recommendations.

Ablation Reboots the Response in Advanced Hepatocellular Carcinoma With Stable or Atypical Response During PD-1 Therapy: A Proof-of-Concept Study

Background: The anti-programmed cell death protein-1 (PD-1) inhibitor is one of the second-line therapies for advanced hepatocellular carcinoma (HCC) after sorafenib failure. The goal of this study is to evaluate the feasibility and safety of ablation on the tumor in patients with advanced HCC who had stable disease or atypical response during single anti-PD-1 therapy after sorafenib failure. Atypical response defined as mixed responses in different lesions of the same individual (e.g., active or stable lesions mixed with progressive lesions).

Patients and Methods: This proof-of-concept clinical trial enrolled 50 patients treated with an anti-PD-1 inhibitor of nivolumab or pembrolizumab monotherapy between July 2015 and Nov 2017. Thirty-three cases with stable disease or atypical response to anti-PD-1 inhibitor received subtotal thermal ablation. The safety and the response of ablation during anti-PD-1 therapy were evaluated. The survival was estimated by the Kaplan-Meier curve.

Results: Of all 50 patients treated with anti-PD-1 therapy, the rate of response, stable disease, atypical and typical progression were 10% (n = 5), 42% (n = 21) 32% (n = 16), and 12% (n = 6), respectively. Additional ablation improved efficacy with tolerable toxicity, and the response rate was increased from 10 to 24% (12/50). The median time to progression, progression-free survival, and overall survival was 6.1 months (95%CI, 2.6–11.2), 5 months (95%CI, 2.9–7.1), and 16.9 months (95%CI, 7.7–26.1), respectively.

Conclusions: This proof-of-concept trial suggested that additional ablation may increase the objective response rate with tolerated toxicity and achieved a relatively better median survival, in advanced HCC patients who had stable or atypical progressive diseases during anti-PD-1 therapy, which may provide a potentially promising strategy to treat advanced HCC.

Trial registration number:ClinicalTrials.gov identifier: NCT03939975.

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.

Safety and Effectiveness of Yttrium-90 Radioembolization around the Time of Immune Checkpoint Inhibitors for Unresectable Hepatic Metastases

PURPOSE

To assess the safety and effectiveness of yttrium-90 radioembolization and checkpoint inhibitor immunotherapy within a short interval for the treatment of unresectable hepatic metastases.

MATERIALS AND METHODS

This single-institution retrospective study included 22 patients (12 men; median age, 65 y ± 11) with unresectable hepatic metastases and preserved functional status (Eastern Cooperative Oncology Group performance status 0/1) who received immunotherapy and radioembolization within a 15-month period (median, 63.5 d; interquartile range, 19.7-178.2 d) from February 2013 to March 2018. Primary malignancies were uveal melanoma (12 of 22; 54.5%), soft tissue sarcoma (3; 13.6%), cutaneous melanoma (3; 14%), and others (4; 18.2%). Studies were reviewed to March 2019 to assess Common Terminology Criteria for Adverse Events grade 3/4 toxicities, disease progression, and death.

RESULTS

There were no grade 4 toxicities within 6 mo of radioembolization. Grade 3 hepatobiliary toxicities occurred in 3 patients (13.6%) within 6 months, 2 from rapid disease progression and 1 from a biliary stricture. Two patients (9.1%) experienced clinical toxicities, including grade 4 colitis at 6 months and hepatic abscess at 3 months. Median overall survival (OS) from first radioembolization was 20 mo (95% confidence interval [CI], 12.5-27.5 mo), and median OS from first immunotherapy was 23 months (95% CI, 15.9-30.1 mo). Within the uveal melanoma subgroup, the median OS from first radioembolization was 17.0 months (95% CI, 14.2-19.8 mo). Median time to progression was 7.8 months (95% CI, 3.3-12.2 mo), and median progression-free survival was 7.8 mo (95% CI, 3.1-12.4 mo).

CONCLUSIONS

Checkpoint immunotherapy around the time of radioembolization is safe, with a low incidence of toxicity independent of primary malignancy.

Emerging Opportunities for Combining Locoregional Therapy with Immune Checkpoint Inhibitors in Hepatocellular Carcinoma

PURPOSE OF REVIEW

Immunotherapy shows great promises in solid tumors. Locoregional therapy can promote systemic immune response in hepatocellular carcinoma (HCC). The combination of locoregional therapy and immune checkpoint inhibitors (ICIs) activates a synergistic effect that can enhance the potency of anti-tumor immunity. This review aims to summarize the underlying mechanisms of locoregional therapy combined with ICIs and their applications in clinical settings.

RECENT FINDINGS

The characteristics of high invasiveness and refractoriness of HCC are what limit the outcomes of treatments. Sorafenib provides an additional treatment option for extrahepatic spread and vascular invasion, making long-term survival possible for patients with advanced HCC to some degree. However, its shortcomings of low response rate and high toxicity result in limited applications in clinical practice. Immunotherapy is a promising emerging therapy with great prospect in HCC, but the self-tolerance of HCC constrains the effectiveness of ICIs. Consequently, the efficacy of single immunotherapy is unsatisfactory. Locoregional therapy can not only destroy primary tumors but also stimulate the release of neoplasm antigens to increase the efficiency of immune response in HCC. Locoregional therapy combined with ICIs may have an amplification effect on immune response. Locoregional therapy plays a vital role in stimulating anti-tumor immune response. The combination of locoregional therapy and ICIs has a synergistic effect on anti-tumor immunity.

Immunotherapy in hepatocellular carcinoma: Combination strategies

Liver cancer is one of the most common causes of cancer death globally, and its incidence in the United States is increasing. Patients with advanced hepatocellular carcinoma (HCC) who are not candidates for surgical resection, liver transplant, or locoregional therapies can be treated with systemic therapies. Multiple agents, including sorafenib, lenvatinib, and regorafenib are approved for use as either first- or second-line therapy in this patient population, but all have relatively modest survival benefits. HCC is potentially susceptible to therapy with checkpoint inhibitors, including agents such as nivolumab and pembrolizumab, which are both approved by the Food and Drug Administration for patients previously treated with sorafenib but have not demonstrated superior overall survival in phase III trials. It is clear that more effective approaches are needed to potentiate the effects of checkpoint inhibitors in patients with HCC. This review will outline and appraise the current literature on the use of checkpoint inhibitors in HCC as part of a combination treatment involving an additional mode of therapy. The list of agents that can be paired with checkpoint inhibitors includes an additional checkpoint inhibitor, vascular endothelial growth factor or vascular endothelial growth factor receptor inhibitors, tyrosine kinase inhibitors, OX-40 agonists, and PT-112 inhibitors. The main non-pharmacologic therapies currently being studied for inclusion in a combination strategy include radiation therapy, trans-arterial chemoembolization, and ablation.