Rationally combining anti-VEGF therapy with checkpoint inhibitors in hepatocellular carcinoma

Anti-angiogenesis Revisited: Combination with Immunotherapy in Solid Tumors

PURPOSE OF REVIEW

Both anti-angiogenesis and immunotherapy are well-established therapeutic options in solid tumors. Here, we review the rationale as well as clinical evidence of combining these two approaches.

RECENT FINDINGS

There is strong rationale and substantial preclinical and clinical evidence that anti-angiogenesis plays a pivotal role in overcoming immunotherapy resistance. The combination of an anti-angiogenic agent and a checkpoint inhibitor offers a more robust treatment option in many clinical trials in a wide variety of solid tumor types. Combination of anti-angiogenesis and immunotherapy has emerged as a standard of care in some tumor types and the indication is expected to expand to more tumor types in the years to come.

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.

Clinical Trials of Immune Checkpoint Inhibitors in Hepatocellular Carcinoma

Introduction: Several immune checkpoint inhibitors (CPIs) are under clinical development in hepatocellular carcinoma (HCC) and the field is advancing rapidly. In this comprehensive review, we discuss published results and report on ongoing clinical trials. Methods: A literature search was carried out using PubMed and EMBASE; data reported at international meetings and clinicaltrials.gov were included as well. The search was updated 5 March 2021. We evaluated studies with monotherapy CPI's, combinations of CPI's and combinations of CPI's with other treatment modalities separately. Only studies with at least 10 included patients were considered. Results: We identified 2649 records published in the English language literature. After review, 29 studies remained, including 12 studies with preliminary data only. The obtained overall response rate of PD-1/PDL-1 monotherapy in phase II studies in the second-line setting was 15-20% with disease control in approximately 60% of patients. The responses were of long duration in a subset of patients. Furthermore, the safety profiles were manageable. However, a phase III study comparing nivolumab with sorafenib in the first-line setting and a phase III study evaluating pembrolizumab versus best supportive care in the second-line setting did not meet their prespecified endpoints. More recently, a phase I/II study of nivolumab and ipilimumab has resulted in a response rate of approximately 30% with a median OS of 22 months in the second-line setting. Multiple trials have been initiated to evaluate CPIs in combination with molecularly targeted drugs, especially anti-angiogenic drugs or local therapy. A phase III study investigating atezolizumab plus bevacizumab versus sorafenib in the first-line setting showed significantly increased survival in the combination arm. Conclusions: The combination of atezolizumab and bevacizumab represents a new standard of care in the first-line setting for fit patients with preserved liver function. CPIs can produce durable tumor remission and induce long-standing anti-tumor immunity in a subgroup of patients with advanced HCC. Although phase III trials of CPI monotherapy have been negative, the combination of PD-1/PD-L1 inhibitors with other anti-angiogenic drugs, CTLA-4 inhibitors or other modalities may result in new treatment options for patients with HCC. Research on predictive biomarkers is crucial for further development of CPIs in HCC.

Combination of molecularly targeted therapies and immune checkpoint inhibitors in the new era of unresectable hepatocellular carcinoma treatment

Multikinase inhibitors (MKIs) have been the only first-line treatment for advanced hepatocellular carcinoma (HCC) for more than a decade, until the approval of immune checkpoint inhibitors (ICIs). Moreover, the combination regimen of atezolizumab (anti-programmed cell death protein ligand 1 antibody) plus bevacizumab (anti-vascular endothelial growth factor monoclonal antibody) has recently been demonstrated to have superior efficacy when compared with sorafenib monotherapy. The remarkable efficacy has made this combination therapy the new standard treatment for advanced HCC. In addition to MKIs, many other molecularly targeted therapies are under investigation, some of which have shown promising results. Therefore, in the era of immuno-oncology, there is a significant rationale for testing the combinations of molecularly targeted therapies and ICIs. Indeed, numerous preclinical and clinical studies have shown the synergic antitumor efficacy of such combinations. In this review, we aim to summarize the current knowledge on the combination of molecularly targeted therapies and immune checkpoint therapies for HCC from both preclinical and clinical perspectives.

Immunotherapy Updates in Advanced Hepatocellular Carcinoma

Simple Summary

Advanced hepatocellular carcinoma (HCC) carries a grim prognosis, which has historically been compounded by a lack of available systemic therapies. Sorafenib monotherapy was the standard of care for front-line treatment of advanced HCC for many years, despite both poor tolerability and lack of durable responses. In the past few years, there have been several clinical trials evaluating the efficacy of immune checkpoint inhibitors for advanced HCC. Use of immune checkpoint inhibitors alone, and in combination with targeted therapies, has led to improved outcomes in both treatment-naïve and subsequent line treatment of advanced HCC. Here we review the role of immunotherapy in the treatment of HCC, describe the mechanistic basis for combination with targeted therapy, and summarize the recent published data as well as ongoing clinical trials for the use of immunotherapy in the treatment of advanced HCC.

Abstract

Hepatocellular carcinoma (HCC) is the second most common cause of cancer death worldwide. HCC tumor development and treatment resistance are impacted by changes in the microenvironment of the hepatic immune system. Immunotherapy has the potential to improve response rates by overcoming immune tolerance mechanisms and strengthening anti-tumor activity in the tumor microenvironment. In this review, we characterize the impact of immunotherapy on outcomes of advanced HCC, as well as the active clinical trials evaluating novel combination immunotherapy strategies. In particular, we discuss the efficacy of atezolizumab and bevacizumab as demonstrated in the IMbrave150 study, which created a new standard of care for the front-line treatment of advanced HCC. However, there are multiple ongoing trials that may present additional front-line treatment options depending on their efficacy/toxicity results. Furthermore, the preliminary data on the application of chimeric antigen receptor (CAR-T) cell therapy for treatment of HCC suggests this may be a promising option for the future of advanced HCC treatment.

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

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

Camrelizumab in combination with apatinib in second-line or above therapy for advanced primary liver cancer: cohort A report in a multicenter phase Ib/II trial

Background

Emerging clinical data suggest that an immune checkpoint inhibitor in combination with an antiangiogenic agent is a reasonable strategy for multiple malignancies. We assessed the combination of camrelizumab with apatinib in pretreated advanced primary liver cancer (PLC, cohort A) from a multicohort phase Ib/II trial.

Methods

Patients with PLC after prior systemic treatment(s) were administered camrelizumab (3 mg/kg, once every 2 weeks) plus apatinib (125, 250, 375, or 500 mg; once per day) in a 3+3 dose-escalation stage and subsequent expansion stage. The primary endpoints were tolerability and safety of study treatment.

Results

From April 2017 to July 2019, 28 patients (21 with hepatocellular carcinoma and 7 with intrahepatic cholangiocarcinoma) received camrelizumab plus apatinib. Two dose-limiting toxicities (both grade 3 diarrhea) were reported in the 500 mg cohort. Therefore, the 375 mg cohort was expanded. Of the 19 patients in the 375 mg cohort, dose reduction to 250 mg occurred in 8 patients within 2 months after treatment initiation. Of the 28 patients with PLC, 26 had grade ≥3 treatment-related adverse events, with hypertension being the most common (9/28). One treatment-related death occurred. The objective response rate was 10.7% (95% CI 2.3% to 28.2%). Median progression-free survival and overall survival were 3.7 months (95% CI 2.0 to 5.8) and 13.2 months (95% CI 8.9 to not reached), respectively.

Conclusion

The combination of camrelizumab with apatinib had a manageable toxicity and promising antitumor activity in patients with advanced PLC. Apatinib at a dose of 250 mg is recommended as a combination therapy for further studies of advanced PLC treatment.

Trial registration numbers

NCT03092895.

Clinical Potential of Kinase Inhibitors in Combination with Immune Checkpoint Inhibitors for the Treatment of Solid Tumors

Oncogenic kinases contribute to immunosuppression and modulate the tumor microenvironment in solid tumors. Increasing evidence supports the fundamental role of oncogenic kinase signaling networks in coordinating immunosuppressive tumor microenvironments. This has led to numerous studies examining the efficacy of kinase inhibitors in inducing anti-tumor immune responses by increasing tumor immunogenicity. Kinase inhibitors are the second most common FDA-approved group of drugs that are deployed for cancer treatment. With few exceptions, they inevitably lead to intrinsic and/or acquired resistance, particularly in patients with metastatic disease when used as a monotherapy. On the other hand, cancer immunotherapies, including immune checkpoint inhibitors, have revolutionized cancer treatment for malignancies such as melanoma and lung cancer. However, key hurdles remain to successfully incorporate such therapies in the treatment of other solid cancers. Here, we review the recent literature on oncogenic kinases that regulate tumor immunogenicity, immune suppression, and anti-tumor immunity. Furthermore, we discuss current efforts in clinical trials that combine kinase inhibitors and immune checkpoint inhibitors to treat breast cancer and other solid tumors.

Strategies to overcome resistance to immune checkpoint blockade in lung cancer

The adoption of Immune checkpoint inhibitors (ICIs) allowed the achievement of impressive long-term survival results in non-small cell lung cancer (NSCLC), but most patients develop resistance to ICI treatment over time. Resistance to ICIs is mediated by several complex mechanisms affecting, but not limited to, tumour cell-intrinsic alterations and the tumour microenvironment. The possibility of modulating the immune response by interfering with specific alternative immune receptors, pathways and mediators might provide additional strategies to delay or prevent the development of resistance. Therefore, a greater in-depth investigation and understanding of these mechanisms aims to identify novel classes of immune targets and subsequently to evaluate potential new strategies for overcoming resistance, which will be assessed in this review.

Sulfasalazine synergistically enhances the inhibitory effects of imatinib against hepatocellular carcinoma (HCC) cells by targeting NFκB, BCR/ABL, and PI3K/AKT signaling pathway-related proteins

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related fatalities worldwide. Identification of second-line therapies for patients with progressive HCC is urgently required as the use of sorafenib and/or regorafenib remains unsatisfactory. Imatinib, a small-molecule kinase inhibitor, is used to treat certain types of cancer, and nuclear factor κB (NFκB) is a positive regulator of cancer cell expansion. The combined use of tyrosine kinase and NFκB inhibitors may have potential for treating HCC. The aim of this work was to assess the potential anticarcinogenic effects of imatinib and sulfasalazine alone or in combination on the human HCC cell lines HEPG2 and Huh-7. Both drugs were shown to affect the phosphoinositide 3-kinase/protein kinase B, phosphorylated signal transducer and activator of translation (p-STAT-3), breakpoint cluster region protein/Abelson proto-oncogene and NFκB pathways. At the transcriptional level, imatinib and sulfasalazine were found to synergistically down-regulate c-MET gene expression. When compared with the activities of either medication alone, combined use of imatinib and sulfasalazine enhanced inhibition of HCC cell proliferation and extended induction of apoptosis. In summary, the presented data suggest that sulfasalazine synergistically potentiates the antitumor effects of imatinib.

Single-nodule hepatitis B virus-associated hepatocellular carcinoma smaller than 3 cm: two phenotypes defined by cluster analysis and their association with the outcome of ablation as the first-line therapy

OBJECTIVES

Hepatocellular carcinoma (HCC) is a heterogeneous disease. This study aimed to identify the heterogeneity related to the prognosis of ablation in patients with single-nodule hepatitis B virus (HBV)-associated HCC ≤3 cm.

METHODS

A total of 359 patients with single-nodule HBV-associated HCC ≤3 cm treated with curative thermal ablation were retrospectively investigated. Hierarchical cluster analysis was applied to obtain more homogeneous patient clusters concerning demographic and physiological characteristics. Discriminant analysis was performed to identify the relatively important variables for cluster analysis. Multiple correspondence analysis (MCA) was used to clarify the relationship between clusters and categorical variables. Overall survival (OS) was compared among clusters using the Kaplan-Meier model.

RESULTS

A two-cluster model was identified. Cluster 1 (n = 85) showed a higher percentage of female and older patients, higher inflammation response (higher prognostic nutritional index [PNI] and Glasgow prognostic score [GPS]), worse liver function (higher albumin-bilirubin grade and Child-Pugh grade), and relatively poorer immune status (higher neutrophil-to-lymphocyte ratio [NLR]) than cluster 2 (n = 274). NLR and GPS were the two most influential variables for cluster analysis (p < .0001). Cluster 2 had a significantly better prognosis than cluster 1. MCA revealed a clear negative correlation between inflammation status and liver function. Compared with cluster 1, the hazard ratios for OS of cluster 2 were 0.47 and 0.52 before and after adjusting for age, respectively (p < .05).

CONCLUSIONS

This study identified two sub-phenotypes of patients with single-nodule HBV-associated HCC ≤3 cm and their association with the outcome of thermal ablation alone as the first-line therapy. Key points Thermal ablation alone as the first-line therapy is not suitable for all patients with single-nodule hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC) ≤3 cm. Patients with single-nodule HBV-associated HCC ≤3 cm can be identified as two sub-phenotypes associated with the outcome of thermal ablation alone as the first-line therapy, based on key preoperative clinical characteristics, especially inflammatory response and immune status. Patients with single-nodule HBV-associated HCC ≤3 cm characterized by late-onset disease, worse liver function, poorer immune status, and higher inflammatory response (with higher inflammatory response being the most important factor) are not suitable for thermal ablation alone as the first-line therapy. In contrast, patients with single-nodule HBV-associated HCC ≤3 cm characterized by early-onset disease, better liver function, lower inflammatory response, and good immune status (with lower inflammatory response being the most important factor) are particularly suitable for thermal ablation alone. Implications for patient care In the treatment of patients with single-nodule HBV-associated HCC ≤3 cm, thermal ablation alone as the first-line therapy should be carefully considered after recognizing the key clinical characteristics, among which inflammatory response and immune status are the two most important factors involved in clinical heterogeneity, and inflammatory response is closely related to the prognosis of thermal ablation alone as the first-line therapy for these patients.

Impact of Sarcopenia, BMI, and Inflammatory Biomarkers on Survival in Advanced Hepatocellular Carcinoma Treated With Anti-PD-1 Antibody

BACKGROUND

Sarcopenia and inflammation are independently associated with worse survival in cancer patients. This study aims to determine the impact of sarcopenia, body mass index (BMI), and inflammatory biomarkers on survival in advanced hepatocellular carcinoma (HCC) patients treated with anti-PD-1 antibody-based immunotherapy.

METHODS

A retrospective review of advanced HCC patients treated with immunotherapy at Winship Cancer Institute between 2015 and 2019 was performed. Baseline computed tomography and magnetic resonance images were collected at mid-L3 level, assessed for skeletal muscle density using SliceOmatic (TomoVision, version 5.0) and converted to skeletal muscle index (SMI) by dividing it by height (m2). Sex-specific sarcopenia was defined by the median value of SMI. The optimal cut for continuous inflammation biomarker was determined by bias-adjusted log-rank test. Overall survival (OS) was set as primary outcome and Cox proportional hazard model was used for association with survival.

RESULTS

A total of 57 patients were included; 77.2% male, 52.6% Caucasian, 58.5% Eastern Cooperative Oncology Group performance status 0-1, 80.7% Child Pugh A. Treatment was second line and beyond in 71.9% of patients. The median follow-up time was 6 months. Sarcopenia cut-off for males and females was SMI of 43 and 39, respectively. 49.1% of patients had sarcopenia. Median OS was 5 versus 14.3 months in sarcopenic versus nonsarcopenic patients (Log-rank P=0.054). Median OS was 5 and 17.5 months in patients with BMI <25 and BMI ≥25, respectively (Log-rank P=0.034). Median OS was 3.6 and 14.3 months for patients with neutrophil-to-lymphocyte ratio (NLR) ≥5.15 versus NLR <5.15 (Log-rank P<0.001). In multivariable Cox regression model, higher baseline NLR was associated with worse OS (hazard ratio [HR]: 4.17, 95% confidence interval [CI]: 1.52-11.39, P=0.005). Sex-specific sarcopenia showed a trend of worse OS (HR: 1.71, 95% CI: 0.73-4.00, P=0.215) but was not statistically significant. BMI<25 was associated with worse OS (HR: 2.28, 95% CI: 0.92-5.65, P=0.076). In the association with progression free survival, neither baseline BMI nor sex-specific sarcopenia showed statistical significance.

CONCLUSION

After controlling for baseline Child Pugh score and NLR, sex-specific sarcopenia does not predict OS. Baseline BMI and NLR together may predict OS in advanced HCC patients treated with anti-PD-1 antibody.

Regorafenib-Avelumab Combination in Patients with Microsatellite Stable Colorectal Cancer (REGOMUNE): A Single-arm, Open-label, Phase II Trial

PURPOSE

Regorafenib is synergistic with immune checkpoint inhibition in colorectal cancer preclinical models.

PATIENTS AND METHODS

This was a single-arm, multicentric phase II trial. Regorafenib was given 3 weeks on/1 week off, 160 mg every day; avelumab 10 mg/kg i.v. was given every 2 weeks, beginning at cycle 1, day 15 until progression or unacceptable toxicity. The primary endpoint was the confirmed objective response rate under treatment, as per RECIST 1.1. The secondary endpoints included a 1-year nonprogression rate, progression-free survival (PFS), and overall survival (OS), safety and biomarkers studies performed on sequential tumor samples obtained at baseline and at cycle 2 day 1.

RESULTS

Forty-eight patients were enrolled in four centers. Forty-three were assessable for efficacy after central radiological review. Best response was stable disease for 23 patients (53.5%) and progressive disease for 17 patients (39.5%). The median PFS and OS were 3.6 months [95% confidence interval (CI), 1.8-5.4] and 10.8 months (95% CI, 5.9-NA), respectively. The most common grade 3 or 4 adverse events were palmar-plantar erythrodysesthesia syndrome (n = 14, 30%), hypertension (n = 11, 23%), and diarrhea (n = 6, 13%). High baseline infiltration by tumor-associated macrophages was significantly associated with adverse PFS (1.8 vs. 3.7 months; P = 0.002) and OS (3.7 months vs. not reached; P = 0.002). Increased tumor infiltration by CD8⁺ T cells at cycle 2, day 1 as compared with baseline was significantly associated with better outcome.

CONCLUSIONS

The combination of regorafenib + avelumab mobilizes antitumor immunity in a subset of patients with microsatellite stable colorectal cancer. Computational pathology through quantification of immune cell infiltration may improve patient selection for further studies investigating this approach.

Addressing resistance to immune checkpoint inhibitor therapy: an urgent unmet need

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of various cancers by reversing the immunosuppressive mechanisms employed by tumors to restore anticancer immunity. Although ICIs have demonstrated substantial clinical efficacy, patient response can vary in depth and duration, and many do not respond at all or eventually develop resistance. ICI resistance mechanisms can be tumor-intrinsic, related to the tumor microenvironment or patient-specific factors. Multiple resistance mechanisms may be present within one tumor subtype, or heterogeneity exists among patients with the same tumor type. Consequently, designing effective combination treatment strategies is challenging. This review will discuss ICI resistance mechanisms, and summarize findings from key preclinical and clinical trials of ICIs, to identify potential treatment strategies or pathways to overcome ICI resistance.

The Growing Skyline of Advanced Hepatocellular Carcinoma Treatment: A Review

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

Percutaneous ethanol injection enhanced the efficacy of radiofrequency ablation in the treatment of HCC: an insight into the mechanism of ethanol action

PURPOSE

To discuss the possible reasons why percutaneous intratumoral ethanol injection (PEI) combined with radiofrequency ablation (RFA) to treat hepatocellular carcinoma (HCC) reduced the recurrence and metastasis compared with RFA alone.

MATERIALS AND METHODS

Forty VX2 tumor-bearing rabbits were randomly divided into four groups (n = 10): the PEI, RFA, PEI-RFA, and control groups. Five rabbits from each group were sacrificed on the 3rd and 7th days after ablation. The number of metastatic tumors in the lung was counted. The ablation volume was measured, and residual tumor specimens were prepared for hematoxylin and eosin staining and caspase-3, Ki-67, and VEGF immunohistochemical staining.

RESULTS

The volume of ablation in the PEI-RFA group was significantly larger than that in the RFA and PEI groups (p < 0.05). However, no significant differences in the number of lung metastases after ablation were observed among the groups (p > 0.05). The number of microthrombi in the PEI-RFA group was greater than that in the control and RFA groups (p < 0.001 and p < 0.05). The Ki-67 labeling index (LI) and H-score of VEGF in the PEI-RFA group were lower than those in the RFA group, while the H-score of caspase-3 was higher than that in the RFA group on the 7th day after ablation (p < 0.05).

CONCLUSION

PEI occluded blood vessels by inducing microthrombi formation, and thereby reducing heat dissipation and increasing the effect of RFA. More importantly, in comparison with an incomplete RFA, PEI-RFA inhibited the increase in the Ki-67 and VEGF expression levels and the decrease in the caspase-3 expression level to happen at some extent and therefore improved the prognosis.

Role of next generation sequencing-based liquid biopsy in advanced non-small cell lung cancer patients treated with immune checkpoint inhibitors: impact of STK11, KRAS and TP53 mutations and co-mutations on outcome

BACKGROUND

Characterization of tumor-related genetic alterations is promising for the screening of new predictive markers in non-small cell lung cancer (NSCLC). Aim of the study was to evaluate prognostic and predictive role of most frequent tumor-associated genetic alterations detected in plasma before starting immune checkpoint inhibitors (ICIs).

METHODS

Between January 2017 and October 2019, advanced NSCLC patients were prospectively screened with plasma next-generation sequencing (NGS) while included in two trials: VISION (NCT02864992), using Guardant360® test, and MAGIC (Monitoring Advanced NSCLC through plasma Genotyping during Immunotherapy: Clinical feasibility and application), using Myriapod NGS-IL 56G Assay. A control group of patients not receiving ICIs was analyzed.

RESULTS

A total of 103 patients receiving ICIs were analyzed: median overall survival (OS) was 20.8 (95% CI: 16.7-24.9) months and median immune-related progression free disease (irPFS) 4.2 (95% CI: 2.3-6.1) months. TP53 mutations in plasma negatively affected OS both in patients treated with ICIs and in control group (P=0.001 and P=0.009), indicating a prognostic role. STK11 mutated patients (n=9) showed a trend for worse OS only if treated with ICIs. The presence of KRAS/STK11 co-mutation and KRAS/STK11/TP53 co-mutation affected OS only in patients treated with ICIs (HR =10.936, 95% CI: 2.337-51.164, P=0.002; HR =17.609, 95% CI: 3.777-82.089, P<0.001, respectively), indicating a predictive role.

CONCLUSIONS

Plasma genotyping demonstrated prognostic value of TP53 mutations and predictive value of KRAS/STK11 and KRAS/STK11/TP53 co-mutations.

Complete Response to the Sequential Treatment with Regorafenib Followed by PD-1 Inhibitor in a Sorafenib-Refractory Hepatocellular Carcinoma Patient

Most patients diagnosed with hepatocellular carcinoma (HCC) have advanced diseases, and many are not eligible for curative therapies. There is growing evidence suggesting that the combination treatment of PD-1/PD-L1 inhibitors and tyrosine kinase inhibitors (TKIs) is becoming a prospective trend for advanced HCC. For those HCC patients with sorafenib resistance, the efficacy of regorafenib combined with PD-1/PD-L1 inhibitors remains unclear. Herein, we represent a case of HCC with lung metastasis in the setting of Hepatitis B virus (HBV)-induced liver cirrhosis responding dramatically to the sequential treatment with regorafenib followed by PD-1 inhibitor after initial liver resection. A 51-year-old man diagnosed with alpha fetoprotein (AFP)-negative HCC underwent liver resection in September 2015 and was found to have solitary liver recurrence and multiple lung metastases in March 2017. He received microwave coagulation therapy (MCT) and trans-arterial chemoembolization (TACE) for liver tumor and treatment was started with sorafenib 400 mg twice daily for controlling lung metastases. In December 2018, an abdominal computerized tomography (CT) scan showed two new lesions in the liver. In March 2019, disease progression of lung metastases was measured and he received 160 mg regorafenib once daily. After a short period of partial response, in December 2019, due to the progression of the disease, he started treatment with regorafenib 160 mg in combination with sintilimab (PD-1 inhibitor) (200 mg, 3 weeks as a cycle). Surprisingly, after five cycles of sintilimab injection, he showed complete response in target lesions. There was no clinical evidence of disease progression, and the side-effects were mild. The current overall survival (OS) is 58 months. Data from this clinical case report suggest that sequential treatment with regorafenib followed by PD-1 inhibitor is a promising therapeutic option for sorafenib-refractory cases of HCCs.

Understanding EGFR heterogeneity in lung cancer

The advances in understanding the inherited biological mechanisms of non-small cell lung cancer harbouring epidermal growth factor receptor (EGFR) mutations led to a significant improvement in the outcomes of patients treated with EGFR tyrosine kinase inhibitors. Despite these clinically impressive results, clinical results are not always uniform, suggesting the need for deepening the molecular heterogeneity of this molecularly defined subgroup of patients beyond the clinical and biological surface.The availability of tissue and blood-based tumour genotyping allows us to improve the understanding of molecular and genetic intratumor heterogeneity, driving the measurement of clonal evaluation in patients with lung cancer carrying EGFR mutations. Genetic diversification, clonal expansion and selection are highly variable patterns of genetic diversity, resulting in different biological entities, also a prerequisite for Darwinian selection and therapeutic failure.Such emerging pieces of evidence on the genetic diversity, including adaptive and immunomodulated aspects, provide further evidence for the role of the tumour microenvironment (TME) in drug-resistance and immune-mediated mechanisms. Matching in daily clinical practice, the detailed genomic profile of lung cancer disease and tracking the clonal evolution could be the way to individualise the further target treatments in EGFR-positive disease. Characterising the tumour and immune microenvironment during the time of the cancer evaluation could be the way forward for the qualitative leap needed from bench to bedside. Such a daring approach, aiming at personalising treatment selection in order to exploit the TME properties and weaken tumour adaptivity, should be integrated into clinical trial design to optimise patient outcome.

Development and validation of a novel pseudogene pair-based prognostic signature for prediction of overall survival in patients with hepatocellular carcinoma

BACKGROUND

There is growing evidence that pseudogenes may serve as prognostic biomarkers in several cancers. The present study was designed to develop and validate an accurate and robust pseudogene pairs-based signature for the prognosis of hepatocellular carcinoma (HCC).

METHODS

RNA-sequencing data from 374 HCC patients with clinical follow-up information were obtained from the Cancer Genome Atlas (TCGA) database and used in this study. Survival-related pseudogene pairs were identified, and a signature model was constructed by Cox regression analysis (univariate and least absolute shrinkage and selection operator). All individuals were classified into high- and low-risk groups based on the optimal cutoff. Subgroups analysis of the novel signature was conducted and validated in an independent cohort. Pearson correlation analyses were carried out between the included pseudogenes and the protein-coding genes based on their expression levels. Enrichment analysis was performed to predict the possible role of the pseudogenes identified in the signature.

RESULTS

A 19-pseudogene pair signature, which included 21 pseudogenes, was established. Patients in high-risk group demonstrated an increased the risk of adverse prognosis in the TCGA cohort and the external cohort (all P < 0.001). The novel pseudogene signature was independent of other conventional clinical variables used for survival prediction in HCC patients in the two cohorts revealed by the multivariate Cox regression analysis (all P < 0.001). Subgroup analysis further demonstrated the diagnostic value of the signature across different stages, grades, sexes, and age groups. The C-index of the prognostic signature was 0.761, which was not only higher than that of several previous risk models but was also much higher than that of a single age, sex, grade, and stage risk model. Furthermore, functional analysis revealed that the potential biological mechanisms mediated by these pseudogenes are primarily involved in cytokine receptor activity, T cell receptor signaling, chemokine signaling, NF-κB signaling, PD-L1 expression, and the PD-1 checkpoint pathway in cancer.

CONCLUSION

The novel proposed and validated pseudogene pair-based signature may serve as a valuable independent prognostic predictor for predicting survival of patients with HCC.

Targeting angiogenesis for liver cancer: Past, present, and future

Liver cancer, mostly hepatocellular carcinoma (HCC), is the second leading cause of cancer mortality globally. Most patients were diagnosed at an advanced stage, and systemic therapy is the standard of care. All the approved systemic therapies for HCC are molecular targeted therapies with anti-angiogenic effects targeting the vascular endothelial growth factor signaling pathway. Sorafenib and lenvatinib are the first-line treatment, and regorafenib, ramucirumab, and cabozantinib are second-line treatment options. Although anti-PD-1 antibodies, including nivolumab and pembrolizumab, demonstrated promising anti-tumor effects as monotherapy for advanced HCC in phase II clinical trials, both failed in phase III studies. Anti-angiogenic treatment remains the backbone of systemic therapy for HCC. In this review, we summarized the approved anti-angiogenic medicines and discussed the potential strategies to improve the efficacy of anti-angiogenic therapy, including combination therapy with other treatments, and discussed the approaches to overcome the drawbacks of anti-angiogenic therapies.

The Role of Sinusoidal Endothelial Cells in the Axis of Inflammation and Cancer Within the Liver

Liver sinusoidal endothelial cells (LSEC) form a unique barrier between the liver sinusoids and the underlying parenchyma, and thus play a crucial role in maintaining metabolic and immune homeostasis, as well as actively contributing to disease pathophysiology. Whilst their endocytic and scavenging function is integral for nutrient exchange and clearance of waste products, their capillarisation and dysfunction precedes fibrogenesis. Furthermore, their ability to promote immune tolerance and recruit distinct immunosuppressive leukocyte subsets can allow persistence of chronic viral infections and facilitate tumour development. In this review, we present the immunological and barrier functions of LSEC, along with their role in orchestrating fibrotic processes which precede tumourigenesis. We also summarise the role of LSEC in modulating the tumour microenvironment, and promoting development of a pre-metastatic niche, which can drive formation of secondary liver tumours. Finally, we summarise closely inter-linked disease pathways which collectively perpetuate pathogenesis, highlighting LSEC as novel targets for therapeutic intervention.

Overview of Current Progress in Immune Checkpoint Inhibitor Therapy for Advanced Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) remains to a common cause of tumor mortality worldwide and represents the most common type of lethal hepatic malignancy. The incidence of HCC is swiftly increasing in western countries and southeast Asia. Despite poor prognosis, traditional treatments for advanced HCC appear to be minimally effective or even useless since patients are usually diagnosed in the advanced stage of disease. In recent years, immune checkpoint blockade has shown promising results in multiple pre-clinical and clinical trials of different solid tumors, including advanced HCC. Novel drugs targeting immune checkpoints, such as nivolumab (anti-PD-1), durvalumab (anti-PD-L1), and tremelimumab (anti-CTLA-4) have been shown to be highly effective and relatively safe in monotherapy or in combination treatment of advanced liver cancer. Unlike other immunotherapies, this approach can rouse human anti-tumor immunity by relieving T-cell exhaustion and inhibiting the evasion of HCC by blocking co-inhibitory signaling transduction accurately. In this review, we will provide current knowledge of several major immune checkpoints and summarize recent data from clinical trials that applied immune checkpoint inhibitors alone or in combination. In addition, this review will discuss the limitations and future prospective of immune checkpoint-targeted therapy for advanced HCC.

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

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

Dual Vascular Endothelial Growth Factor Receptor and Fibroblast Growth Factor Receptor Inhibition Elicits Antitumor Immunity and Enhances Programmed Cell Death-1 Checkpoint Blockade in Hepatocellular Carcinoma

BACKGROUND AND AIMS

Combining anti-angiogenic therapy with immune checkpoint blockade with anti-programmed cell death-1 (PD-1) antibodies is a promising treatment for hepatocellular carcinoma (HCC). Tyrosine kinase inhibitors are well-known anti-angiogenic agents and offer potential for combination with anti-PD-1 antibodies. This study investigated the possible underlying immunomodulatory mechanisms of combined therapy.

METHODS

HCC tissue samples for RNA-sequencing (RNA-seq) were obtained from patients with differential prognoses following anti-PD-1 treatment. Recombinant basic fibroblast growth factor (bFGF) and vascular endothelial growth factor A (VEGFA) were used to stimulate T cells following lenvatinib or sorafenib treatment, respectively. T cell function was analyzed by flow cytometry and lactate dehydrogenase assay. In vivo experiments were conducted in murine H22 and Hepa 1-6 competent models of HCC. Local immune infiltration in the tumor microenvironment (TME) was assessed using multicolor flow cytometry. Gene regulation was evaluated by RNA-seq. Microvascular density was measured by immunohistochemistry, and PD-1 ligand (PD-L1) induction was quantified by western blot.

RESULTS

The baseline expression of VEGF and fibroblast growth factor (FGF) in patients with progressive disease was significantly higher than in patients achieving stable disease following anti-PD-1 treatment. VEGFA and bFGF significantly upregulated the expression of PD-1, cytotoxic T-lymphocyte-associated protein-4, and Tim-3 on T cells, while inhibiting the secretion of interferon gamma (IFNG) and granzyme B and suppressing T cell cytotoxicity. This immunosuppressive effect was reverted by lenvatinib but not sorafenib. Furthermore, dual lenvatinib/anti-PD-1 antibody therapy led to better antitumor effects than either sorafenib or fibroblast growth factor receptor (FGFR) inhibitor (BGJ398) in H22 murine models of HCC. Combined lenvatinib/anti-PD-1 treatment also led to long-term immune memory formation, while synergistically modulating the TME and enhancing the cytotoxic effect of T cells. Finally, lenvatinib inhibited PD-L1 expression on human umbilical vein endothelial cells, which improved the function of T cells.

CONCLUSIONS

Inhibition of vascular endothelial growth factor receptor and FGFR augmented the efficacy of anti-PD-1 antibodies. Combined lenvatinib/anti-PD-1 treatment appears to exert antitumor activity by synergistically modulating effector T cell function in the TME and by mutually regulating tumor vessel normalization.

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

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

Is the era of sorafenib over? A review of the literature

Hepatocellular carcinoma (HCC) is one of the most severe diseases worldwide. For the different stages of HCC, there are different clinical treatment strategies, such as surgical therapy for the early stage, and transarterial chemoembolization (TACE) and selective internal radiation therapy (SIRT) for intermediate-stage disease. Systemic treatment, which uses mainly targeted drugs, is the standard therapy against advanced HCC. Sorafenib is an important first-line therapy for advanced HCC. As a classically effective drug, sorafenib can increase overall survival markedly. However, it still has room for improvement because of the heterogeneity of HCC and acquired resistance. Scientists have reported the acquired sorafenib resistance is associated with the anomalous expression of certain genes, most of which are also related with HCC onset and development. Combining sorafenib with inhibitors targeting these genes may be an effective treatment. Combined treatment may not only overcome drug resistance, but also inhibit the expression of carcinoma-related genes. This review focuses on the current status of sorafenib in advanced HCC, summarizes the inhibitors that can combine with sorafenib in the treatment against HCC, and provides the rationale for clinical trials of sorafenib in combination with other inhibitors in HCC. The era of sorafenib in the treatment of HCC is far from over, as long as we find better methods of medication.

Regulation of the tumor immune microenvironment and vascular normalization in TNBC murine models by a novel peptide

Triple-negative breast cancer (TNBC) is a highly metastatic and aggressive disease with limited treatment options. Recently, the combination of the immune checkpoint inhibitor (ICI) atezolizumab (anti-PD-L1) with nab-paclitaxel was approved following a clinical trial that showed response rates in at least 43% of patients. While this approval marks a major advance in the treatment of TNBC it may be possible to improve the efficacy of ICI therapies through further modulation of the suppressive tumor immune microenvironment (TIME). Several factors may limit immune response in TNBC including aberrant growth factor signaling, such as VEGFR2 and cMet signaling, inefficient vascularization, poor delivery of drugs and immune cells, and the skewing of immune cell populations toward immunosuppressive phenotypes. Here we investigate the immune-modulating properties of AXT201, a novel 20 amino-acid integrin-binding peptide in two syngeneic mouse TNBC models: 4T1-BALB/c and NT4-FVB. AXT201 treatment improved survival in the NT4 model by 20% and inhibited the growth of 4T1 tumors by 47% over 22 days post-inoculation. Subsequent immunohistochemical analyses of 4T1 tumors also showed a 53% reduction in vascular density and a 184% increase in pericyte coverage following peptide treatment. Flow cytometry analyses demonstrated evidence of a more favorable anti-tumor immune microenvironment following treatment with AXT201, including significant decreases in the populations of T regulatory cells, monocytic myeloid-derived suppressor cells, and PD-L1 expressing cells and increased expression of T cell functional markers. Together, these findings demonstrate immune-activating properties of AXT201 that could be developed in combination with other immunomodulatory agents in the treatment of TNBC.

Small Molecular Immune Modulators as Anticancer Agents

After decades of intense effort, immune checkpoint inhibitors have been conclusively demonstrated to be effective in cancer treatments and thus are revolutionizing the concepts in the treatment of cancers. Immuno-oncology has arrived and will play a key role in cancer treatment in the foreseeable future. However, efforts to find novel methods to improve the immune response to cancer have not ceased. Small-molecule approaches offer inherent advantages over biologic immunotherapies since they can cross cell membranes, penetrate into tumor tissue and tumor microenvironment more easily, and are amenable to be finely controlled than biological agents, which may help reduce immune-related adverse events seen with biologic therapies and provide more flexibility for the combination use with other therapies and superior clinical benefit. On the one hand, small-molecule therapies can modulate the immune response to cancer by restoring the antitumor immunity, promoting more effective cytotoxic lymphocyte responses, and regulating tumor microenvironment, either directly or epigenetically. On the other hand, the combination of different mechanisms of small molecules with antibodies and other biologics demonstrated admirable synergistic effect in clinical settings for cancer treatment and may expand antibodies' usefulness for broader clinical applications. This chapter provides an overview of small-molecule immunotherapeutic approaches either as monotherapy or in combination for the treatment of cancer.

Dual Programmed Death Receptor-1 and Vascular Endothelial Growth Factor Receptor-2 Blockade Promotes Vascular Normalization and Enhances Antitumor Immune Responses in Hepatocellular Carcinoma

BACKGROUND AND AIMS

Activation of the antitumor immune response using programmed death receptor-1 (PD-1) blockade showed benefit only in a fraction of patients with hepatocellular carcinoma (HCC). Combining PD-1 blockade with antiangiogenesis has shown promise in substantially increasing the fraction of patients with HCC who respond to treatment, but the mechanism of this interaction is unknown.

APPROACH AND RESULTS

We recapitulated these clinical outcomes using orthotopic-grafted or induced-murine models of HCC. Specific blockade of vascular endothelial receptor 2 (VEGFR-2) using a murine antibody significantly delayed primary tumor growth but failed to prolong survival, while anti-PD-1 antibody treatment alone conferred a minor survival advantage in one model. However, dual anti-PD-1/VEGFR-2 therapy significantly inhibited primary tumor growth and doubled survival in both models. Combination therapy reprogrammed the immune microenvironment by increasing cluster of differentiation 8-positive (CD8+ ) cytotoxic T cell infiltration and activation, shifting the M1/M2 ratio of tumor-associated macrophages and reducing T regulatory cell (Treg) and chemokine (C-C motif) receptor 2-positive monocyte infiltration in HCC tissue. In these models, VEGFR-2 was selectively expressed in tumor endothelial cells. Using spheroid cultures of HCC tissue, we found that PD-ligand 1 expression in HCC cells was induced in a paracrine manner upon anti-VEGFR-2 blockade in endothelial cells in part through interferon-gamma expression. Moreover, we found that VEGFR-2 blockade increased PD-1 expression in tumor-infiltrating CD4+ cells. We also found that under anti-PD-1 therapy, CD4+ cells promote normalized vessel formation in the face of antiangiogenic therapy with anti-VEGFR-2 antibody.

CONCLUSIONS

We show that dual anti-PD-1/VEGFR-2 therapy has a durable vessel fortification effect in HCC and can overcome treatment resistance to either treatment alone and increase overall survival in both anti-PD-1 therapy-resistant and anti-PD-1 therapy-responsive HCC models.

Treatment options after first-line immunotherapy in metastatic NSCLC

Introduction: The recent approvals of checkpoint inhibitors as single agents or in combination with chemotherapy with programmed death ligand 1 expression of < or ≥1% have challenged clinicians when it is time to begin a metastatic lung cancer patient in second-line therapy. The advantages given by immunotherapy over conventional chemotherapy such as improved overall survival and a better toxicity profile make the second-line clinical scenario more difficult for a patient who faces a likely inferior regimen as well as toxicity which may significantly impact the quality of life.Areas covered: Options given today by the National Comprehensive Cancer Network are very limited, and essentially, we go back to conventional cytotoxic agents alone or in combination with biological agents if possible. In this article, we discuss the actual treatment available for this difficult scenario and some of the ongoing trials which aim to address this dilemma.Expert commentary: This is an unmet need in lung cancer management; we need a better understanding of the mechanism of resistance to immunotherapy so we can target them once the patient moves to second-line treatment.

Transcriptomic analysis reveals the oncogenic role of S6K1 in hepatocellular carcinoma

The p70 ribosomal protein S6 kinase 1 (S6K1), a serine/threonine kinase, is commonly overexpressed in a variety of cancers. However, its expression level and functional roles in hepatocellular carcinoma (HCC), which ranks as the third leading cause of cancer-related death worldwide, is still largely unknown. In the current report, we show the in vivo and in vitro overexpression of S6K1 in HCC. In the functional analysis, we demonstrate that S6K1 is required for the proliferation and colony formation abilities in HCC. By using comparative transcriptomic analysis followed by gene ontology enrichment analysis and Ingenuity Pathway Analysis, we find that the depletion of S6K1 can elevate the expression of a cluster of apoptotic genes, tumor suppressor genes and immune responsive genes. Moreover, the knockdown of S6K1 is predicted to reduce the tumorigenicity of HCC through the regulation of hubs of genes including STAT1, HDAC4, CEBPA and ONECUT1. In conclusion, we demonstrate the oncogenic role of S6K1 in HCC, suggesting the possible use of S6K1 as a therapeutic target for HCC treatment.

Developments in predictive biomarkers for hepatocellular carcinoma therapy

Introduction: Hepatocellular carcinoma (HCC) is the most common primary tumor of the liver and the third largest cause of cancer-relateddeaths worldwide. Potentially curative treatments (surgical resection, radiofrequency or liver transplantation) are only available for few patients, while transarterial chemoembolization (TACE) or systemic agents are the best treatments for intermediate and advanced stage disease. The identification of markers that allow us to choose the best treatment for the patient is urgent.Areas covered: In this review we summarize the potential biological markers to predict the efficacy of all treatment available in patients with HCC and discuss anew biomarker with ahigher potential of success in the next future.Expert opinion: HCC is aheterogeneous disease. Tumors are heterogeneous in terms of genetic alteration,with spatial heterogeneity in cellular density, necrosis and angiogenesis.This heterogeneity may affect prognosis and treatment. Tumor heterogeneity can be difficult to quantify with traditional imaging due to subjective assessment of images; the same for sampling biopsy, which evaluates only asmall part of the tumor. We think that combining multi-OMICSwith radiomics represents apromising strategy for evaluating tumor heterogenicity and for identifying biomarkers of response and prognosis.

Effectiveness and Safety of Combination Therapy of Transarterial Chemoembolization and Apatinib for Unresectable Hepatocellular Carcinoma in the Chinese Population: A Meta-Analysis

BACKGROUND

The combination of transarterial chemoembolization (TACE) and apatinib has been used in the treatment of intermediate or advanced hepatocellular carcinoma (HCC). However, its effectiveness and safety are also argued.

METHODS

Eligible studies were collected from a computer search of literatures published from the database establishment to May 2019 in PubMed, Web of Science, EMBASE, Ovid, the Cochrane Library, Wanfang Database, China National Knowledge Infrastructure, and China Biology Medicine Disc. The objective response rate (ORR), the disease control rate (DCR), survival rate (SR), and the incidences of treatment-related adverse effects (AEs) were collected as the relevant outcomes. Data were analyzed through fixed/random effects of meta-analysis models with RevMan 5.3 software.

RESULTS

Eight randomized controlled clinical trials comprising 528 patients and 4 cohort studies comprising 226 patients were eventually included. Compared to the control group treated with TACE solely, combination therapy group, in which intermediate or advanced HCC patients were treated with TACE and apatinib, significantly enhanced ORR (relative risk [RR] 2.06, 95% CI 1.63-2.61, p < 0.001), DCR (RR 1.65, 95% CI 1.24-2.20, p < 0.001), and whole SRs of 6-month (RR 1.52, 95% CI 1.08-2.14, p = 0.02), 1-year (RR 1.52, 95% CI 1.25-1.84, p < 0.001), and 2-year (RR 1.84, 95% CI 1.34-2.54, p < 0.001). The incidence of hand foot syndrome, proteinuria, hypertension, and diarrhea was significantly increased in the combination therapy group compared with the control group (p < 0.05), and the incidence of nausea and vomiting, fever, and myelosuppression, respectively, was similar in 2 groups (p > 0.05).

CONCLUSIONS

The combination therapy of TACE and apatinib can enhance the clinical effectiveness better than TACE solely in patients with intermediate or advanced HCC, while increase in the AEs is usually tolerable.

New Insight into Therapies Targeting Angiogenesis in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a malignancy characterized by neoangiogenesis that is determined by an augmented production of proangiogenesis factors by tumor and adjacent cells. This unbalanced angiogenesis process is a key feature of HCC carcinogenesis and progression. Proangiogenic factors also have a relevant role in the generation and maintenance of an immunosuppressive tumor microenvironment. Several therapeutic options for HCC treatment are based on the inhibition of angiogenesis, both in the early/intermediate stages of the disease and in the late stages of the disease. Conventional treatment options employing antiangiogenic approaches provide for the starving of tumors of their blood supply to avoid the refueling of oxygen and nutrients. An emerging alternative point of view is the normalization of vasculature leading to enhance tumor perfusion and oxygenation, potentially capable, when proposed in combination with other treatments, to improve delivery and efficacy of other therapies, including immunotherapy with checkpoint inhibitors. The introduction of novel biomarkers can be useful for the definition of the most appropriate dose and scheduling for these combination treatment approaches. The present review provides a wide description of the pharmaceutical compounds with an antiangiogenic effect proposed for HCC treatment and investigated in clinical trials, including antibodies and small-molecule kinase inhibitors.

Immunotherapy for hepatocellular carcinoma: recent advances and future perspectives

The introduction of immunotherapies has been a major development in the treatment of many advanced cancers, including hepatocellular carcinoma (HCC). We are entering a new era of systemic therapy for advanced HCC associated with an explosion of clinical trial activity. Data from phase I/II studies of checkpoint inhibitors in advanced HCC have been promising, with durable objective response rates of approximately 20% seen (in both first- and second-line settings) and acceptable safety profiles (including immune-mediated hepatitis). Phase III studies evaluating anti-programmed cell death protein 1 (anti-PD-1) and anti-programmed cell death ligand 1 (anti-PD-L1) antibodies compared with sorafenib are already underway. The potential synergistic effects of anti-PD-1/anti-PD-L1 when used in combination with agents against other checkpoint molecules, systemic therapies, as well as conventional surgical and locoregional therapies are also being explored in upcoming clinical trials. Aside from this, other strategies to harness the immune system, including chimeric antigen receptor-engineered T cells, natural killer cell therapies, and peptide vaccines directed against HCC antigens have entered phase I/II studies. Current limitations of immunotherapies and areas of future research include the accurate assessment and prediction of tumor response, overcoming the immunosuppressive effects of a hypoxic microenvironment, and the management of immune-related hepatitis in patients who already have limited liver reserve.

Can Combined Therapy Benefit Immune Checkpoint Blockade Response in Hepatocellular Carcinoma?

Background:

Hepatocellular Carcinoma (HCC) is one of the most common cancers with high mortality rate. The effects of most therapies are limited. The Immune Checkpoint Blockade (ICB) improves the prognosis in multiple malignancies. The application of immune checkpoint blockade to hepatocellular carcinoma patients has recently started. Early phase clinical trials have shown some benefits to cancer patients.

Methods/Results:

This review focuses on the immune system of liver and clinical trials of ICB. In particular, we analyze the mechanisms by which immune checkpoint blockade therapies can be used for the treatment of hepatocellular carcinoma patients, then examine the factors in cancer resistance to the therapies and finally suggest possible combination therapies for the treatment of hepatocellular carcinoma patients.

Conclusion:

ICB is a promising therapy for advanced HCC patients. Combined therapy exhibits a great potential to enhance ICB response in these patients. The better understanding of the factors influencing the sensitivity of ICB and more clinical trials will consolidate the efficiency and minimize the adverse effects of ICB.

Combinatorial Approaches With Checkpoint Inhibitors to Enhance Anti-tumor Immunity

Treatment of cancer patients has been recently revolutionized by the application of various immunotherapeutics. However, the response rates are still limited ranging between approximately 20 and 40% suggesting that combinations of immunotherapy with conventional treatment, like chemotherapy, radiation, epigenetic modulators, targeted therapies using small molecules as well as other (immuno) therapeutics, might be an option to increase systemic anti-tumor immunity. It is postulated that different non-immune based therapies in combination with immunotherapies could reprogram the immune suppressive tumor microenvironment and enhance the immunogenicity of tumor cells leading to an improved therapeutic efficacy and a better patients' outcome. Despite there exist various examples of increased objective responses achieved by adding these different therapies to immunotherapies, strategies for rational and evidence-based design of checkpoint inhibitor combinations to maximize the clinical benefit for patients are urgently required. Therefore, the main purpose of this review is to summarize recent results obtained from experimental models and clinical trials to enhance tumor immunogenicity by combining immunotherapy with other therapeutic options to maximize patients' outcome and minimize adverse events.

Evolving Landscape of Systemic Therapy for Hepatocellular Carcinoma: Breakthroughs, Toxicities, and Future Frontiers

The incidence and death rates of hepatocellular carcinoma (HCC) are rising. For more than a decade, the multikinase inhibitor sorafenib was the only U.S. Food and Drug Administration (FDA)-approved systemic therapy for HCC. However, since 2017, five additional agents have been approved in the first- or second-line setting. Although this represents an incredible victory for the field, there are no clear guidelines for agent selection on the basis of either patient or tumor characteristics. Here, we review the available systemic therapy options for advanced HCC and reported clinical data for each. We outline each agent's unique toxicity profile, potential impact on patient quality of life, monitoring recommendations, and supportive strategies. Last, we review molecular and immunologic classifications of HCC as well as preclinical data that may serve as a basis for future biomarker enriched clinical trials to enable precision oncology care in HCC.

The potential combinational immunotherapiesfor treatment of hepatocellular carcinoma

The treatment choices available for hepatocellular carcinoma (HCC) are limited and unsatisfactory. Recent improvements in our understanding of the mechanism involving immune checkpoints, including programmed cell death protein 1 (PD1), programmed death-ligand 1 (PD-L1), and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), and also progress in the development of medicines make immunotherapy a promising approach to the treatment of numerous cancers, especially HCC. However, around 40% of patients still suffer from a progressive disease when treated with a monotherapy. Several clinical trials applying a combination therapy including immune checkpoint inhibitors have demonstrated the durable antitumor activity of these approaches in HCC patients. These clinical trials were done with the intent of evaluating the safety of these combination therapies, as well as whether they help improve the overall survival of patients. This study reviewed the recent progress in the use of combination therapies including immunotherapy in treating patients with HCC.

LKB1 and Tumor Metabolism: The Interplay of Immune and Angiogenic Microenvironment in Lung Cancer

Liver kinase B1 (LKB1) is a tumor suppressor gene whose inactivation is frequent in different tumor types, especially in lung adenocarcinoma (about 30% of cases). LKB1 has an essential role in the control of cellular redox homeostasis by regulating ROS production and detoxification. Loss of LKB1 makes the tumor cell more sensitive to oxidative stress and consequently to stress-inducing treatments, such as chemotherapy and radiotherapy. LKB1 loss triggers complex changes in tumor microenvironment, supporting a role in the regulation of angiogenesis and suggesting a potential role in the response to anti-angiogenic treatment. On the other hand, LKB1 deficiency can promote an immunosuppressive microenvironment and may be involved in primary resistance to anti-PD-1/anti-PD-L1, as it has been reported in lung cancer. The aim of this review is to discuss interactions of LKB1 with the tumor microenvironment and the potential applications of this knowledge in predicting response to treatment in lung cancer.

Low-Dose Apatinib Optimizes Tumor Microenvironment and Potentiates Antitumor Effect of PD-1/PD-L1 Blockade in Lung Cancer

The lack of response to treatment in most lung cancer patients suggests the value of broadening the benefit of anti-PD-1/PD-L1 monotherapy. Judicious dosing of antiangiogenic agents such as apatinib (VEGFR2-TKI) can modulate the tumor immunosuppressive microenvironment, which contributes to resistance to anti-PD-1/PD-L1 treatment. We therefore hypothesized that inhibiting angiogenesis could enhance the therapeutic efficacy of PD-1/PD-L1 blockade. Here, using a syngeneic lung cancer mouse model, we demonstrated that low-dose apatinib alleviated hypoxia, increased infiltration of CD8⁺ T cells, reduced recruitment of tumor-associated macrophages in tumor and decreased TGFβ amounts in both tumor and serum. Combining low-dose apatinib with anti-PD-L1 significantly retarded tumor growth, reduced the number of metastases, and prolonged survival in mouse models. Anticancer activity was evident after coadministration of low-dose apatinib and anti-PD-1 in a small cohort of patients with pretreated advanced non-small cell lung cancer. Overall, our work shows the rationale for the treatment of lung cancer with a combination of PD-1/PD-L1 blockade and low-dose apatinib.

Immune Checkpoint Inhibitors in Hepatocellular Carcinoma: Opportunities and Challenges

Hepatocellular carcinoma (HCC) is the most common malignancy worldwide, and is especially common in China. A total of 70%-80% of patients are diagnosed at an advanced stage and can receive only palliative care. Sorafenib has been the standard of care for a decade, and promising results for regorafenib as a second-line and lenvatinib as a first-line treatment were reported only 1 or 2 years ago. FOLFOX4 was recently recommended as a clinical practice guideline by the China Food and Drug Administration. All approved systemic therapies remain unsatisfactory, with limited objective response rates and poor overall survival. Immune checkpoint inhibitors (CPIs) offer great promise in the treatment of a rapidly expanding spectrum of solid tumors. Immune checkpoint molecules are involved in almost the whole process of viral-related hepatitis with cirrhosis and HCC and in the most important resistance mechanism of sorafenib. The approval of nivolumab by the U.S. Food and Drug Administration on September 23, 2017, for the treatment of patients with HCC, based only on a phase I/II clinical trial, is a strong hint that immunotherapy will introduce a new era of HCC therapy. CPI-based strategies will soon be a main approach in anticancer treatment for HCC, and we will observe the rapid advances in the therapeutic use of CPIs, even in an adjuvant setting, with great interest. How shall we face the opportunities and challenges? Can we dramatically improve the prognosis of patients with HCC? This review may provide some informed guidance. IMPLICATIONS FOR PRACTICE: Immune checkpoint molecules are involved in almost the whole process of viral-related hepatitis with cirrhosis and hepatocellular carcinoma (HCC) and in the most important resistance mechanism of sorafenib. As all approved systemic therapies in HCC remain unsatisfactory, checkpoint inhibitor (CPI)-based strategies will soon be a main approach in anticancer treatment for advanced stage of HCC, even in an adjuvant setting. In virus-related HCC, especially hepatitis B virus-related HCC, whether CPIs can control virus relapse should be further investigated. Combination strategies involving conventional therapies and immunotherapies are needed to increase clinical benefit and minimize adverse toxicities with regard to the underlying liver disease.

Immunomodulatory activity of lenvatinib contributes to antitumor activity in the Hepa1-6 hepatocellular carcinoma model

Angiogenesis inhibitors such as lenvatinib and sorafenib, and an immune checkpoint inhibitor (ICI), nivolumab, are used for anticancer therapies against advanced hepatocellular carcinoma (HCC). Combination treatments comprising angiogenesis inhibitors plus ICIs are promising options for improving clinical benefits in HCC patients, and clinical trials are ongoing. Here, we investigated the antitumor and immunomodulatory activities of lenvatinib (a multiple receptor tyrosine kinase inhibitor targeting vascular endothelial growth factor receptor 1‐3, fibroblast growth factor receptor 1‐4, platelet‐derived growth factor receptor α, KIT and RET) and the combined antitumor activity of lenvatinib plus anti‐programmed cell death 1 (PD‐1) antibody in the Hepa1‐6 mouse HCC syngeneic model. We found that the antitumor activities of lenvatinib and sorafenib were not different in immunodeficient mice, but lenvatinib showed more potent antitumor activity than sorafenib in immunocompetent mice. The antitumor activity of lenvatinib was greater in immunocompetent mice than in immunodeficient mice and was attenuated by CD8⁺ T cell depletion. Treatment with lenvatinib plus anti‐PD‐1 antibody resulted in more tumor regression and a higher response rate compared with either treatment alone in immunocompetent mice. Single‐cell RNA sequencing analysis demonstrated that treatment with lenvatinib with or without anti‐PD‐1 antibody decreased the proportion of monocytes and macrophages population and increased that of CD8⁺ T cell populations. These data suggest that lenvatinib has immunomodulatory activity that contributes to the antitumor activity of lenvatinib and enhances the antitumor activity in combination treatment with anti‐PD‐1 antibody. Combination treatment of lenvatinib plus anti‐PD‐1 antibody therefore warrants further investigation against advanced HCC.