Initial experience of anti-PD1 therapy with nivolumab in advanced hepatocellular carcinoma

Comprehensive assessment of TECENTRIQ® and OPDIVO®: analyzing immunotherapy indications withdrawn in triple-negative breast cancer and hepatocellular carcinoma

Atezolizumab (TECENTRIQ®) and nivolumab (OPDIVO®) are both immunotherapeutic indications targeting programmed cell death 1 ligand 1 (PD-L1) and programmed cell death 1 (PD-1), respectively. These inhibitors hold promise as therapies for triple-negative breast cancer (TNBC) and hepatocellular carcinoma (HCC) and have demonstrated encouraging results in reducing the progression and spread of tumors. However, due to their adverse effects and low response rates, the US Food and Drug Administration (FDA) has withdrawn the approval of atezolizumab in TNBC and nivolumab in HCC treatment. The withdrawals of atezolizumab and nivolumab have raised concerns regarding their effectiveness and the ability to predict treatment responses. Therefore, the current study aims to investigate the immunotherapy withdrawal of PD-1/PD-L1 inhibitors, specifically atezolizumab for TNBC and nivolumab for HCC. This study will examine both the structural and clinical aspects. This review provides detailed insights into the structure of the PD-1 receptor and its ligands, the interactions between PD-1 and PD-L1, and their interactions with the withdrawn antibodies (atezolizumab and nivolumab) as well as PD-1 and PD-L1 modifications. In addition, this review further assesses these antibodies in the context of TNBC and HCC. It seeks to elucidate the factors that contribute to diverse responses to PD-1/PD-L1 therapy in different types of cancer and propose approaches for predicting responses, mitigating the potential risks linked to therapy withdrawals, and optimizing patient outcomes. By better understanding the mechanisms underlying responses to PD-1/PD-L1 therapy and developing strategies to predict these responses, it is possible to create more efficient treatments for TNBC and HCC.

Efficacy and Safety of PD-1/PD-L1 Inhibitors in Advanced Hepatocellular Carcinoma: A Systematic Review and Meta-analysis

INTRODUCTION

Programmed cell death 1 (PD-1) and programmed cell death ligand 1 (PD-L1) inhibitors have been increasingly employed for the treatment of various cancers in clinical practice. This study aimed to systematically evaluate the efficacy and safety of PD-1/PD-L1 inhibitors for advanced hepatocellular carcinoma (HCC).

METHODS

PubMed, EMBASE, Cochrane library, Web of Science, and Abstracts of American Society of Clinical Oncology proceedings databases were searched. Objective response rate (ORR), disease control rate (DCR), median progression-free survival (PFS), median overall survival (OS), and incidence of adverse events (AEs) and drug withdrawal were pooled. Odds ratio (OR) and hazard ratio (HR) were calculated to analyze the difference in the ORR, DCR, PFS, and OS between groups.

RESULTS

Among the 14,902 initially identified papers, 98 studies regarding use of PD-1/PD-L1 inhibitors in advanced HCC were included. Based on different criteria of response in solid tumors, the pooled ORR, DCR, and median PFS was 16-36%, 54-74%, and 4.5-6.8 months, respectively. The pooled median OS was 11.9 months. Compared to multitarget tyrosine kinase inhibitors (TKIs), PD-1/PD-L1 inhibitors monotherapy significantly increased ORR (OR 2.73, P < 0.00001) and OS (HR 0.97, P = 0.05), and PD-1/PD-L1 inhibitors combined with TKIs significantly increased ORR (OR 3.17, P < 0.00001), DCR (OR 2.44, P < 0.00001), PFS (HR 0.58, P < 0.00001), and OS (HR 0.58, P < 0.00001). The pooled incidence of all-grade AEs, grade ≥ 3 AEs, and drug withdrawal was 71%, 25%, and 7%, respectively.

CONCLUSION

On the basis of the present systematic review and meta-analysis, PD-1/PD-L1 inhibitors should be the preferred treatment choice for advanced HCC owing to their higher antitumor effect and improved outcomes.

Clinical Outcomes Associated with Monotherapy and Combination Therapy of Immune Checkpoint Inhibitors as First-Line Treatment for Advanced Hepatocellular Carcinoma in Real-World Practice: A Systematic Literature Review and Meta-Analysis

BACKGROUND

Immune checkpoint inhibitors (ICIs)-based therapy has recently been demonstrated to greatly ameliorate survival outcomes in advanced hepatocellular carcinoma (HCC). We aimed to evaluate clinical outcomes of ICIs-based monotherapy and combination therapy as first-line treatment of adults with advanced HCC in real-world practice by conducting a systematic literature review and meta-analysis.

METHODS

PubMed, Web of Science, and Embase were searched up to 25 April 2022. Retrospective or prospective real-world studies evaluating progression-free survival (PFS), overall survival (OS), objective response rate (ORR), disease control rate (DCR), and treatment-related adverse events (TRAEs) of patients with advanced HCC receiving first-line ICIs-based therapy were included.

RESULTS

Of 7805 studies retrieved, 38 were deemed eligible for inclusion. For patients receiving first-line ICIs-based therapy in real-world practice, the pooled median PFS and OS were 7.03 (95% CI: 5.55-8.51) and 14.39 (95% CI: 10.91-17.86) months. The ORR and DCR were 0.432 (95% CI: 0.327-0.538) and 0.756 (95% CI: 0.677-0.836), according to mRECIST 1.1, 0.317 (95% CI: 0.218-0.416) and 0.740 (95% CI: 0.644-0.835), judged by RECIST 1.1. The best outcomes of survival and response rate were observed in ICIs-based combination therapy of ICIs, TKIs, plus LRTs. Furthermore, ORR, DCR judged by mRECIST 1.1, and PFS could be potential prognostic factors for OS.

CONCLUSIONS

This research revealed diversified first-line ICIs-based therapies for advanced HCC in real-world practice. Future studies are needed to adopt prospective, multicentric and comparative designs to test the ICIs-based combination therapies, especially triple therapies of ICIs, TKIs, plus LRTs.

Mechanisms and Clinical Trials of Hepatocellular Carcinoma Immunotherapy

Hepatocellular carcinoma (HCC), one of the most common and lethal tumors worldwide, is usually not diagnosed until the disease is advanced, which results in ineffective intervention and unfavorable prognosis. Small molecule targeted drugs of HCC, such as sorafenib, provided only about 2.8 months of survival benefit, partially due to cancer stem cell resistance. There is an urgent need for the development of new treatment strategies for HCC. Tumor immunotherapies, including immune check point inhibitors, chimeric antigen receptor T cells (CAR-T) and bispecific antibodies (BsAb), have shown significant potential. It is known that the expression level of glypican-3 (GPC3) was significantly increased in HCC compared with normal liver tissues. A bispecific antibody (GPC3-S-Fabs) was reported to recruit NK cells to target GPC3 positive cancer cells. Besides, bispecific T-cell Engagers (BiTE), including GPC3/CD3, an aptamer TLS11a/CD3 and EpCAM/CD3, were recently reported to efficiently eliminate HCC cells. It is known that immune checkpoint proteins programmed death-1 (PD-1) binding by programmed cell death-ligand 1 (PD-L1) activates immune checkpoints of T cells. Anti-PD-1 antibody was reported to suppress HCC progression. Furthermore, GPC3-based HCC immunotherapy has been shown to be a curative approach to prolong the survival time of patients with HCC in clinically trials. Besides, the vascular endothelial growth factor (VEGF) inhibitor may inhibit the migration, invasion and angiogenesis of HCC. Here we review the cutting-edge progresses on mechanisms and clinical trials of HCC immunotherapy, which may have significant implication in our understanding of HCC and its immunotherapy.

Anti-Programmed death-1 therapy in advanced hepatocellular carcinoma: A real-world experience

Nivolumab is an effective and safe treatment in HCC.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

The Role of Immunotherapy in Hepatocellular Carcinoma: A Systematic Review and Pooled Analysis of 2,402 Patients

BACKGROUND

Immune checkpoints inhibitors (ICIs) have emerged as a treatment option for several malignancies. Nivolumab, pembrolizumab, nivolumab plus ipilimumab, and atezolizumab plus bevacizumab have been approved for the management of advanced-stage hepatocellular carcinoma (HCC). We aimed to systematically review the literature and summarize the characteristics and outcomes of patients with HCC treated with ICIs.

METHODS

A systematic literature search of PubMed, the Cochrane Library, and ClinicalTrials.gov was performed according to the PRISMA statement (end of search date: November 7, 2020). Quality of evidence assessment was also performed.

RESULTS

Sixty-three articles including 2,402 patients were analyzed, 2,376 of whom received ICIs for unresectable HCC. Response to ICIs could be evaluated in 2,116 patients; the overall objective response rate (ORR) and disease control rate (DCR) were 22.7% and 60.7%, respectively, and the mean overall survival (OS) was 15.8 months. The ORR, DCR, and OS for nivolumab (n = 846) were 19.7%, 51.1%, and 18.7 months, respectively; for pembrolizumab (n = 435) they were 20.7%, 64.6% and 13.3 months, respectively. The combination of atezolizumab/bevacizumab (n = 460) demonstrated an ORR and DCR of 30% and 77%, respectively. The overall rate of treatment discontinuation because of adverse events was 14.9%. Fifteen patients received ICIs in the liver transplant (LT) setting (one pre-LT for bridging, 14 for post-LT recurrence); fatal graft rejection was reported in 40.0% (n = 6/15) and mortality in 80.0% (n = 12/15).

CONCLUSION

ICIs are safe and effective against unresectable HCC, but caution is warranted regarding their use in the LT setting because of the high graft rejection rate.

IMPLICATIONS FOR PRACTICE

This systematic review pooled the outcomes from studies reporting on the use of immune checkpoint inhibitors (ICIs) for the management of 2,402 patients with advanced-stage hepatocellular carcinoma (HCC), 2,376 of whom had unresectable HCC. The objective response rate and disease control rate were 22.7% and 60.7%, respectively, and the mean overall survival was 15.8 months. The overall rate of treatment discontinuation because of adverse events was 14.9%. Fifteen patients received ICIs in the liver transplant (LT) setting (one pre-LT for bridging, 14 for post-LT recurrence). Six of these patients experienced graft rejection (40.0%).

Therapy in Advanced Hepatocellular Carcinoma

Treatment of advanced hepatocellular carcinoma (HCC) is challenging. Several randomized clinical trials are investigating the efficacy of systemic therapy, immunotherapy, and locoregional therapy as monotherapy or combined with other modalities in the treatment of HCC. Systemic therapy is the preferred treatment in advanced disease. To date, multiple first-line and second-line agents received Food and Drug Administration approval. For over a decade, sorafenib was the only first-line agent. In May 2020, combination of atezolizumab and bevacizumab has been approved as a first-line systemic regimen. Lenvatinib is another first-line agent that has multikinase activity. Second-line agents include cabozantinib, regorafenib, ramucirumab, and nivolumab. Adoptive cell transfer therapy is a highly specific immunotherapy that has shown antitumor activity against HCC. Oncolytic viruses are genetically modified viruses that infect cancer cells and induce apoptosis. Locoregional therapies such as transarterial chemoembolization and radioembolization have shown a potential benefit in selected patients with advanced HCC. In this review, we aim to summarize the treatment options available for advanced HCC.

Programmed cell death protein 1 (PD-1)-inhibition in hepatocellular carcinoma (HCC): a single center experience

BACKGROUND

The prognosis for advanced Hepatocellular carcinoma (HCC)is still very poor. Despite initial usefulness of immune checkpoint inhibitor (PD-1), phase 3 trials failed to show significant benefit of PD-1 inhibition with nivolumab or pembrolizumab in the first and second line therapy of HCC. Clinical evidence of PD-1 inhibition in patients with advanced and heavily pretreated HCC outside clinical trials is extremely limited. In this study, we analyzed the clinical experience with PD-1 inhibition in patients with heavily pretreated HCC.

METHODS

Between May 2016 and January 2019 14 patients with advanced and heavily pretreated HCC were treated with nivolumab or pembrolizumab at the University Hospital Bonn, Germany. Base line characteristics prior to immunotherapy, immunohistochemistry of different immunological markers, beneficial outcome and safety were recorded and retrospectively analyzed.

RESULTS

Immunotherapy with PD-1 inhibition was well tolerated and resulted in significant clinical benefit as last line therapy. Median overall survival (OS) was 6.6 months (95%CI:3.9-11.8), progression-free survival (PFS) was 5.3 months (95%CI:2.4-11.7) and overall response rate (ORR) was 30.8%. One patient reached a complete remission.

CONCLUSIONS

Despite numerous pretreatments, PD-1 inhibition was well tolerated and showed clinical benefit in patients with heavily pretreated HCC.

Effectiveness of nivolumab versus regorafenib in hepatocellular carcinoma patients who failed sorafenib treatment

Background/Aims

Several treatment options are currently available for patients with hepatocellular carcinoma (HCC) failing previous sorafenib treatment. We aimed to compare the effectiveness of regorafenib and nivolumab in these patients.

Methods

Consecutive HCC patients who received regorafenib or nivolumab after failure of sorafenib treatment were included. Primary endpoint was overall survival (OS) and secondary endpoints were time to progression, tumor response rate, and adverse events. Inverse probability of treatment weighting (IPTW) using the propensity score was conducted to reduce treatment selection bias.

Results

Among 150 study patients, 102 patients received regorafenib and 48 patients received nivolumab. Median OS was 6.9 (95% confidence interval [CI], 3.0–10.8) months for regorafenib and 5.9 (95% CI, 3.7–8.1) months for nivolumab (P=0.77 by log-rank test). In multivariable analysis, nivolumab was associated with prolonged OS (vs. regorafenib: adjusted hazard ratio [aHR], 0.54; 95% CI, 0.30–0.96; P=0.04). Time to progression was not significantly different between groups (nivolumab vs. regorafenib: aHR, 0.82; 95% CI, 0.51–1.30; P=0.48). HRs were maintained after IPTW. Objective response rates were 5.9% and 16.7% in patients treated with regorafenib and nivolumab, respectively (P=0.04).

Conclusions

After sorafenib failure, the use of nivolumab may be associated with improved OS and better objective response rate as compared to using regorafenib.

Role of cellular, molecular and tumor microenvironment in hepatocellular carcinoma: Possible targets and future directions in the regorafenib era

Hepatocellular carcinoma (HCC) remains as one of the major causes of cancer-related mortality, despite the recent development of new therapeutic options. Regorafenib, an oral multikinase inhibitor, is the first systemic therapy that has a survival benefit for patients with advanced HCC that have a poor response to sorafenib. Even though regorafenib has been approved by the FDA, the clinical trial for regorafenib treatment does not show significant improvement in overall survival. The impaired efficacy of regorafenib caused by various resistance mechanisms, including epithelial-mesenchymal transitions, inflammation, angiogenesis, hypoxia, oxidative stress, fibrosis and autophagy, still needs to be resolved. In this review, we provide insight on regorafenib microenvironmental, molecular and cellular mechanisms and interactions in HCC treatment. The aim of this review is to help physicians select patients that would obtain the maximal benefits from regorafenib in HCC therapy.

Cytolytic Activity of Effector T-lymphocytes Against Hepatocellular Carcinoma is Improved by Dendritic Cells Pulsed with Pooled Tumor Antigens

Cellular immunotherapy is a promising new therapeutic approach for hepatocellular carcinoma (HCC), which has a high recurrence rate, irrespective of the treatment administered. In this study, we attempted to improve the cytolytic activity of effector T-lymphocytes against HCC. T-lymphocytes were activated by monocyte-derived dendritic cells (DCs) pulsed with cell lysate or RNA prepared from HCC cell lines. Monocytes were activated for differentiation into DCs by treatment with the IL4 and GM-CSF. DCs were pulsed with cell lysate or RNA prepared from a single cell line or combinations of two or three HCC cell lines, and then co-cultured with autologous T-lymphocytes with the intent of creating specific cytotoxicity. We discovered that DCs pulsed with total RNA effectuated greater T-lymphocyte function than DCs pulsed with total cell lysate, as evidenced by greater cytolytic activities against HCC target cells. The percentage of Huh7, HepG2, and SNU449 cell apoptosis at effector:target ratio of 10:1 was 42.6 ± 4.5% (p = 0.01), 33.6 ± 3.1% (p = 0.007), and 21.4 ± 1.4% (p < 0.001), respectively. DCs pulsed with pools of antigens prepared from three cell lines improved the cytolytic function of effector T-lymphocytes by approximately two-fold (p < 0.001), which suggests that this approach be further developed and applied for adoptive transfer treatment of HCC.

Adverse Events of Concurrent Immune Checkpoint Inhibitors and Antiangiogenic Agents: A Systematic Review

Background: Immune checkpoint blockade has revolutionized the treatment of multiple malignancies. Currently, however, the effect is not universal, with objective response rates (ORR) of about 15–25%, and even lower for some cancers. Abnormal vasculature is a hallmark of most solid tumors and plays a role in immune evasion. Growing body of evidence suggests that vascular normalization and immune reprogramming could operate synergistic effect, resulting in an enhanced therapeutic efficacy. However, the benefit of antitumor efficacy must be weighed against the risk of added toxicity. In this systematic review, we summarize severe toxicity observed in such a kind of combination regimen.

Methods: PubMed and Embase were searched for English references published up to May 31, 2019, with MeSH and keywords search terms of immune checkpoint inhibitors (ICIs) and antiangiogenic agents approved for using in solid tumors. Studies performing concomitant use of ICIs and antiangiogenic agents, and also reporting severe treatment-related adverse events (trAEs) (≥grade 3), were included for further analysis.

Results: A total of 32 studies including a total of 2,324 participants were analyzed. Limited available data suggests that both antiangiogenic monoclonal antibodies (mAbs) and tyrosine kinase inhibitors (TKIs) show potential risk of increasing treatment-related toxicity when combined with ICIs. Overall, the total incidence of severe adverse events (AEs) associated with ICIs plus mAbs (44.5%) is lower than that of ICIs plus TKIs (60.1%). However, the trAEs observed in combination therapy are mostly consistent with the known safety profiles of corresponding monotherapy, and they seem to be largely related to antiangiogenic agents, rather than a true immune-related adverse event (irAE) predominantly due to ICIs. The majority of trAEs are intervened by holding ICI treatment and adding corticosteroids, as well as reducing dose or adjusting administration frequency of the antiangiogenic drugs.

Conclusions: Concurrent use of ICIs and antiangiogenic agents shows potential treatment-related toxicity. Further research is required to compare the efficacy and safety of the combination regimen and corresponding monotherapy and identify predictive biomarkers, as well as explore dose, duration, and sequencing schedules of drugs.

Locoregional Therapy, Immunotherapy and the Combination in Hepatocellular Carcinoma: Future Directions

Image-guided locoregional therapies (LRTs) have long been a vital part of treatment regimens for hepatocellular carcinoma (HCC). Ablation, chemoembolization, and radioembolization are examples of commonly used treatment techniques for HCC. This review describes the various methods utilized to treat HCC in the field of interventional oncology and also focuses on new and novel treatment concepts being developed in the field including the use of novel immunotherapy agents and combination therapy of LRTs with immunotherapy.

Stereotactic Body Radiation Therapy as an Alternative Treatment for Patients with Hepatocellular Carcinoma Compared to Sorafenib: A Propensity Score Analysis

BACKGROUND AND AIMS

Stereotactic body radiation therapy (SBRT) has emerged as a safe and effective treatment for patients with hepatocellular carcinoma (HCC), but its role in patients with advanced HCC is not yet defined. In this study, we aim to assess the efficacy and safety of SBRT in comparison to sorafenib treatment in patients with advanced HCC.

METHODS

We included 901 patients treated with sorafenib at six tertiary centers in Europe and Asia and 122 patients treated with SBRT from 13 centers in Germany and Switzerland. Medical records were reviewed including laboratory parameters, treatment characteristics and development of adverse events. Propensity score matching was performed to adjust for differences in baseline characteristics. The primary endpoint was overall survival (OS) and progression-free survival.

RESULTS

Median OS of SBRT patients was 18.1 (10.3-25.9) months compared to 8.8 (8.2-9.5) in sorafenib patients. After adjusting for different baseline characteristics, the survival benefit for patients treated with SBRT was still preserved with a median OS of 17.0 (10.8-23.2) months compared to 9.6 (8.6-10.7) months in sorafenib patients. SBRT treatment of intrahepatic lesions in patients with extrahepatic metastases was also associated with improved OS compared to patients treated with sorafenib in the same setting (17.0 vs. 10.0 months, p = 0.012), whereas in patients with portal vein thrombosis there was no survival benefit in patients with SBRT.

CONCLUSIONS

In this retrospective comparative study, SBRT showed superior efficacy in HCC patients compared to patients treated with sorafenib.

Association of Platelet Count and Mean Platelet Volume with Overall Survival in Patients with Cirrhosis and Unresectable Hepatocellular Carcinoma

BACKGROUND

Platelets have been reported to influence tumor biology and may promote metastasis. Traditionally, thrombocytopenia, a hallmark of cirrhosis, was associated with hepatocellular carcinoma (HCC) development. However, the impact of platelet count on outcome in patients with established HCC is not well studied.

METHODS

Outcomes of patients with cirrhosis diagnosed with HCC between 1995 and 2013 (derivation cohort) and 2000-2016 (validation cohort) who were not eligible for surgical treatment and did not receive antiplatelet therapy were retrospectively studied. Thrombocytopenia was defined as platelet count < 150 g/L. High mean platelet volume (MPV) was defined as ≥median value of the respective cohort (derivation cohort: ≥11 fL; validation cohort: ≥10.6 fL).

RESULTS

Among 626 patients with unresectable HCC, thrombocytopenia was present in 378 (60.4%) and was associated with favorable baseline tumor characteristics: lower diameter of the largest nodule (5.6 ± 3.2 vs. 7.6 ± 4.2 cm), less extrahepatic spread (9.5 vs. 20.2%, both p < 0.001), less macrovascular invasion (21.2 vs. 31.0%, p = 0.005), and lower BCLC stages (63.0 vs. 73.4% BCLC C/D; p = 0.007) as compared to patients with normal platelet count. On univariate analysis, thrombocytopenia and larger MPV were associated with longer overall survival (OS) (thrombocytopenia: median OS [95% CI], 11.5 [9.3-13.8] vs. 5.5 [3.8-7.1] months; p = 0.001; MPV ≥11 fL: 11.7 [9.1-14.2] vs. 6.0 [4.4-7.6] months; p < 0.001). In multivariate analysis, the combined variable of thrombocytopenia and larger MPV was independently associated with longer OS (HR [95% CI], 0.80 [0.65-0.98]; p = 0.029). These results were confirmed in an independent external validation cohort of 525 patients with cirrhosis and HCC. Again, patients with thrombocytopenia and high MPV had significantly longer OS (15.3 [11.7-18.9] vs. 9.3 [7.4-11.2] months; p < 0.001).

CONCLUSIONS

Thrombocytopenia and higher MPV are associated with better outcome in patients with advanced HCC. These findings may prompt further clinical research on additive antiplatelet therapy in the prevention and management of HCC.

Programmed cell death protein-1 (PD-1)/programmed death-ligand-1 (PD-L1) axis in hepatocellular carcinoma: prognostic and therapeutic perspectives

Hepatocellular carcinoma (HCC) is the most common primary neoplasia of the liver. There have been tremendous efforts in the development of therapeutic strategies in the last decades. As opposed to other cancer entities immunotherapy has just recently gained popularity in HCC. Among various immunotherapy approaches, programmed cell death protein-1 (PD-1), and its ligand programmed death receptor ligand-1 (PD-L1) axis became one of the most promising pathway of the decade. The scientific interest in PD-1/PD-L1 axis is definitely justified due to: ability to detect PD-L1 expression in patients that underwent resection for HCC with prognostic values; the role of serum PD-L1 as a tool to identify early recurrences and to monitor treatment outcome; PD-1/PDL1 is a highly targetable pathway, with possible predictive markers, and with high clinical applicability that might help us in selecting a subgroup of HCC patients who are most likely to benefit from PD-1/PD-L1 inhibitors. In this review we will first discuss the prognostic role of PD-1/PD-L1 as a bio-marker in various clinical scenarios. Afterwards we will critically analyse the recently published trials with PD-1/PD-L1 inhibitors in HCC either alone or in combination with other treatment modalities. The higher focus will be on clinical rather than preclinical studies. Nevertheless, the strengths and limits of PD-1/PD-L1 axis in both prognosis and therapy of HCC will be highlighted.

The Use of the Humanized Mouse Model in Gene Therapy and Immunotherapy for HIV and Cancer

HIV and cancer remain prevailing sources of morbidity and mortality worldwide. There are current efforts to discover novel therapeutic strategies for the treatment or cure of these diseases. Humanized mouse models provide the investigative tool to study the interaction between HIV or cancer and the human immune system in vivo. These humanized models consist of immunodeficient mice transplanted with human cells, tissues, or hematopoietic stem cells that result in reconstitution with a nearly full human immune system. In this review, we discuss preclinical studies evaluating therapeutic approaches in stem cell-based gene therapy and T cell-based immunotherapies for HIV and cancer using a humanized mouse model and some recent advances in using checkpoint inhibitors to improve antiviral or antitumor responses.