The evolving treatment paradigm of advanced hepatocellular carcinoma: putting all the pieces back together

Liver cancer in ovo models for preclinical testing

Immunotherapies have significantly improved the prognosis of patients with advanced hepatocellular carcinoma (HCC), although more than 70% of patients still do not respond to this first-line treatment. Many new combination strategies are currently being explored, which drastically increases the need for preclinical models that would allow large-scale testing of new immunotherapies and their combinations. We developed several in ovo (in the egg) human liver cancer models, based on human tumor xenografts of different liver cancer cell lines on the chicken embryo's chorioallantoic membrane. We characterized the angiogenesis, as well as the collagen accumulation and tumor immune microenvironment, and tested atezolizumab (anti-PD-L1) plus bevacizumab (anti-VEGF) treatment. Our results show the involvement of chicken immune cells in tumor growth, reproducing a classical non-inflamed "cold" as well as inflamed "hot" tumor status, depending on the in ovo liver cancer model. The treatment by atezolizumab and bevacizumab was highly efficient in the "hot" tumor model PLC/PRF/5 in ovo with the reduction of tumor size by 76% (p ≤ .0001) compared with the control, whereas the efficacy was limited in the "cold" Hep3B in ovo tumor. The contribution of the anti-PD-L1 blockade to the anti-tumoral effect in the PLC/PRF/5 in ovo model was demonstrated by the efficacy of atezolizumab monotherapy (p = .0080, compared with the control). To conclude, our study provides a detailed characterization and rational arguments that could help to partially replace conventional laboratory animals with a more ethical model, suited to the current needs of preclinical research of new immunotherapies for liver cancer.

Targeting NAD+ metabolism of hepatocellular carcinoma cells by lenvatinib promotes M2 macrophages reverse polarization, suppressing the HCC progression

BACKGROUND

Lowered nicotinamide adenine dinucleotide (NAD+) levels in tumor cells drive tumor hyperprogression during immunotherapy, and its restoration activates immune cells. However, the effect of lenvatinib, a first-line treatment for unresectable hepatocellular carcinoma (HCC), on NAD+ metabolism in HCC cells, and the metabolite crosstalk between HCC and immune cells after targeting NAD+ metabolism of HCC cells remain unelucidated.

METHODS

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) and ultra-high-performance liquid chromatography multiple reaction monitoring-mass spectrometry (UHPLC-MRM-MS) were used to detect and validate differential metabolites. RNA sequencing was used to explore mRNA expression in macrophages and HCC cells. HCC mouse models were used to validate the effects of lenvatinib on immune cells and NAD+ metabolism. The macrophage properties were elucidated using cell proliferation, apoptosis, and co-culture assays. In silico structural analysis and interaction assays were used to determine whether lenvatinib targets tet methylcytosine dioxygenase 2 (TET2). Flow cytometry was performed to assess changes in immune cells.

RESULTS

Lenvatinib targeted TET2 to synthesize and increase NAD+ levels, thereby inhibiting decomposition in HCC cells. NAD+ salvage increased lenvatinib-induced apoptosis of HCC cells. Lenvatinib also induced CD8+ T cells and M1 macrophages infiltration in vivo. And lenvatinib suppressed niacinamide, 5-Hydroxy-L-tryptophan and quinoline secretion of HCC cells, and increased hypoxanthine secretion, which contributed to proliferation, migration and polarization function of macrophages. Consequently, lenvatinib targeted NAD+ metabolism and elevated HCC-derived hypoxanthine to enhance the macrophages polarization from M2 to M1. Glycosaminoglycan binding disorder and positive regulation of cytosolic calcium ion concentration were characteristic features of the reverse polarization.

CONCLUSIONS

Targeting HCC cells NAD+ metabolism by lenvatinib-TET2 pathway drives metabolite crosstalk, leading to M2 macrophages reverse polarization, thereby suppressing HCC progression. Collectively, these novel insights highlight the role of lenvatinib or its combination therapies as promising therapeutic alternatives for HCC patients with low NAD+ levels or high TET2 levels.

Progression patterns and therapeutic sequencing following immune checkpoint inhibition for hepatocellular carcinoma: An international observational study

BACKGROUND AND AIMS

Different approaches are available after the progression of disease (PD) to immune checkpoint inhibitors (ICIs) for hepatocellular carcinoma (HCC), including the continuation of ICI, treatment switching to tyrosine kinase inhibitors (TKIs) and cessation of anticancer therapy. We sought to characterise the relationship between radiological patterns of progression and survival post-ICI, also appraising treatment strategies.

METHODS

We screened 604 HCC patients treated with ICIs, including only those who experienced PD by data cut-off. We evaluated post-progression survival (PPS) according to the treatment strategy at PD and verified its relationship with radiological patterns of progression: intrahepatic growth (IHG), new intrahepatic lesion (NIH), extrahepatic growth (EHG), new extrahepatic lesion (NEH) and new vascular invasion (nVI).

RESULTS

Of 604 patients, 364 (60.3%) experienced PD during observation. Median PPS was 5.3 months (95% CI: 4.4-6.9; 271 events). At the data cut-off, 165 patients (45%) received no post-progression anticancer therapy; 64 patients (17.6%) continued ICI beyond PD. IHG (HR 1.64 [95% CI: 1.21-2.22]; p = .0013) and nVI (HR 2.15 [95% CI: 1.38-3.35]; p = .0007) were associated with shorter PPS. Multivariate models adjusted for progression patterns, treatment line and albumin-bilirubin grade and Eastern Cooperative Oncology Group performance status at PD confirmed receipt of ICI beyond PD with (HR 0.17, 95% CI: 0.09-0.32; p < .0001) or without subsequent TKI (HR 0.39, 95% CI: 0.26-0.58; p < .0001) as predictors of prolonged PPS versus no anticancer therapy.

CONCLUSIONS

ICI-TKI sequencing is a consolidated option in advanced HCC. nVI and IHG predict a poorer prognosis. Despite lack of recommendation, the continuation of ICI beyond progression in HCC is adopted clinically: future efforts should appraise which patients benefit from this approach.

eIF4A1 Is a Prognostic Marker and Actionable Target in Human Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a primary liver tumor with high lethality and increasing incidence worldwide. While tumor resection or liver transplantation is effective in the early stages of the disease, the therapeutic options for advanced HCC remain limited and the benefits are temporary. Thus, novel therapeutic targets and more efficacious treatments against this deadly cancer are urgently needed. Here, we investigated the pathogenetic and therapeutic role of eukaryotic initiation factor 4A1 (eIF4A1) in this tumor type. We observed consistent eIF4A1 upregulation in HCC lesions compared with non-tumorous surrounding liver tissues. In addition, eIF4A1 levels were negatively correlated with the prognosis of HCC patients. In HCC lines, the exposure to various eIF4A inhibitors triggered a remarkable decline in proliferation and augmented apoptosis, paralleled by the inhibition of several oncogenic pathways. Significantly, anti-growth effects were achieved at nanomolar concentrations of the eIF4A1 inhibitors and were further increased by the simultaneous administration of the pan mTOR inhibitor, Rapalink-1. In conclusion, our results highlight the pathogenetic relevance of eIF4A1 in HCC and recommend further evaluation of the potential usefulness of pharmacological combinations based on eIF4A and mTOR inhibitors in treating this aggressive tumor.

Preliminary evidence of safety and tolerability of atezolizumab plus bevacizumab in patients with hepatocellular carcinoma and Child-Pugh A and B cirrhosis: A real-world study

BACKGROUND AND AIMS

Atezolizumab plus bevacizumab (AtezoBev) is the standard of care for first-line treatment of unresectable HCC. No evidence exists as to its use in routine clinical practice in patients with impaired liver function.

APPROACH AND RESULTS

In 216 patients with HCC who were consecutively treated with AtezoBev across 11 tertiary centers, we retrospectively evaluated treatment-related adverse events (trAEs) graded (G) according to Common Terminology Criteria for Adverse Events v5.0, including in the analysis all patients treated according to label (n = 202, 94%). We also assessed overall survival (OS), progression-free survival (PFS), overall response (ORR), and disease control rates (DCR) defined by Response Evaluation Criteria in Solid Tumors v1.1. Disease was mostly secondary to viral hepatitis, namely hepatitis C (n = 72; 36%) and hepatitis B infection (n = 35, 17%). Liver function was graded as Child-Pugh (CP)-A in 154 patients (76%) and CP-B in 48 (24%). Any grade trAEs were reported by 143 patients (71%), of which 53 (26%) were G3 and 3 (2%) G4. Compared with CP-A, patients with CP-B showed comparable rates of trAEs. Presence and grade of varices at pretreatment esophagogastroduodenoscopy did not correlate with bleeding events. After a median follow-up of 9.0 months (95% CI, 7.8-10.1), median OS was 14.9 months (95% CI, 13.6-16.3), whereas median PFS was 6.8 months (95% CI, 5.2-8.5). ORR and DCR were respectively 25% and 73%, with no difference across CP classes.

CONCLUSIONS

This study confirms reproducible safety and efficacy of AtezoBev in routine practice. Patients with CP-B reported similar tolerability compared with CP-A, warranting prospective evaluation of AtezoBev in this treatment-deprived population.

PKCα/ZFP64/CSF1 axis resets the tumor microenvironment and fuels anti-PD1 resistance in hepatocellular carcinoma

BACKGROUND & AIMS

Despite remarkable advances in treatment, most patients with hepatocellular carcinoma (HCC) respond poorly to anti-programmed cell death 1 (anti-PD1) therapy. A deeper insight into the tolerance mechanism of HCC against this therapy is urgently needed.

METHODS

We performed next-generation sequencing, multiplex immunofluorescence, and dual-color immunohistochemistry and constructed an orthotopic HCC xenograft tumor model to identify the key gene associated with anti-PD1 tolerance. A spontaneously tumorigenic transgenic mouse model, an in vitro coculture system, mass cytometry, and multiplex immunofluorescence were used to explore the biological function of zinc finger protein 64 (ZFP64) on tumor progression and immune escape. Molecular and biochemical strategies like RNA-sequencing, chromatin immunoprecipitation-sequencing and mass spectrometry were used to gain insight into the underlying mechanisms of ZFP64.

RESULTS

We showed that ZFP64 is frequently upregulated in tumor tissues from patients with anti-PD1-resistant HCC. Elevated ZFP64 drives anti-PD1 resistance by shifting macrophage polarization toward an alternative activation phenotype (M2) and fostering an inhibitory tumor microenvironment. Mechanistically, we primarily demonstrated that protein kinase C alpha (PKCα) directly phosphorylates ZFP64 at S226, leading to its nuclear translocation and the transcriptional activation of macrophage colony-stimulating factor (CSF1). HCC-derived CSF1 transforms macrophages to the M2 phenotype to drive immune escape and anti-PD1 tolerance. Notably, Gö6976, a protein kinase inhibitor, and lenvatinib, a multi-kinase inhibitor, reset the tumor microenvironment and restore sensitivity to anti-PD1 by blocking the PKCα/ZFP64/CSF1 axis.

CONCLUSIONS

We propose that the PKCα/ZFP64/CSF1 axis is critical for triggering immune evasion and anti-PD1 tolerance. Inhibiting this axis with Gö6976 or lenvatinib overcomes anti-PD1 resistance in HCC.

LAY SUMMARY

Despite remarkable treatment progress, most patients with hepatocellular carcinoma respond poorly to anti-PD1 therapy (a type of immunotherapy). A deeper insight into the tolerance mechanisms to this therapy is urgently needed. Herein, we unravel a previously unexplored mechanism linking tumor progression, macrophage polarization, and anti-PD1 resistance, and offer an attractive novel target for anti-PD1 combination therapy, which may benefit patients with hepatocellular carcinoma.

Immune cell infiltration and immunotherapy in hepatocellular carcinoma

Hepatocellular carcinoma is a highly malignant tumor and patients yield limited benefits from the existing treatments. The application of immune checkpoint inhibitors is promising but the results described in the literature are not favorable. It is therefore urgent to systematically analyze the immune microenvironment of HCC and screen the population best suited for the application of immune checkpoint inhibitors to provide a basis for clinical treatment. In this study, we collected The Cancer Genome Atlas Liver Hepatocellular Carcinoma (TCGA-LIHC)-related data sets to evaluate the immune microenvironment and immune cell infiltration (ICI) in HCC. Three independent ICI subtypes showing significant differences in survival were identified. Further, TCGA-LIHC immunophenoscore (IPS) was used to identify the differentially expressed genes between high- and low-IPS in HCC, so as to identify the immune gene subtypes in HCC tumors. The ICI score model for HCC was constructed, whereby we divided HCC samples into high- and low-score groups based on the median ICI score. The differences between these groups in genomic mutation load and immunotherapy benefit in HCC were examined in detail to provide theoretical support for accurate immunotherapy strategy in HCC. Finally, four genes were screened, which could accurately predict the subtype based on the tumor immune infiltration score. The findings may provide a basis and simplify the process for screening clinical drugs suitable for relevant subgroups.

Regorafenib Combined with PD-1 Blockade Immunotherapy versus Regorafenib as Second-Line Treatment for Advanced Hepatocellular Carcinoma: A Multicenter Retrospective Study

Purpose

To evaluate the safety and efficacy of regorafenib combined with anti-PD-1 antibody sintilimab (rego-sintilimab) as a second-line treatment for advanced hepatocellular carcinoma (HCC).

Methods

This multicenter retrospective study evaluated consecutive patients with advanced HCC who received rego-sintilimab (rego-sintilimab group) or regorafenib alone (regorafenib group) as a second-line treatment from January 2019 to December 2020. Adverse events, objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) were compared between the two groups. Uni- and multi-variable analyses of prognostic factors for OS and PFS were performed using Cox proportional hazard regression models.

Results

In total, 113 patients were included in the study: 58 received rego-sintilimab and 55 received regorafenib. The rego-sintilimab group had higher ORR (36.2% vs 16.4%, P = 0.017), longer PFS (median 5.6 vs 4.0 months; P = 0.045), and better OS (median 13.4 vs 9.9 months; P = 0.023) than the regorafenib group. Regorafenib alone, Child-Pugh B, and neutrophil-to-lymphocyte ratio (NLR) > 3.6 were independent prognostic factors for poor OS. Regorafenib alone, α-fetoprotein level, and NLR > 3.6 were independent prognostic factors for poor PFS. Subgroup analyses showed a survival benefit of rego-sintilimab in patients with NLR ≤ 3.6 (hazard ratio 0.518 [95% CI, 0.257–0.955]) but not in those with NLR > 3.6 (0.852 [0.461–1.572]); P = 0.002 for interaction. The difference in incidence of grade 3/4 adverse events between the two groups was not statistically significant (39.7% vs 30.9%; P = 0.331).

Conclusion

Rego-sintilimab was tolerated and led to better OS than regorafenib as a second-line treatment for advanced HCC patients, especially in those with NLR ≤ 3.6.

Immunomodulation for hepatocellular carcinoma therapy: current challenges

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Histone Acetylation Regulator-Mediated Acetylation Patterns Define Tumor Malignant Pathways and Tumor Microenvironment in Hepatocellular Carcinoma

Background

Histone acetylation modification is one of the most common epigenetic methods used to regulate chromatin structure, DNA repair, and gene expression. Existing research has focused on the importance of histone acetylation in regulating tumorigenicity, tumor progression, and tumor microenvironment (TME) but has not explored the potential roles and interactions of histone acetylation regulators in TME cell infiltration, drug sensitivity, and immunotherapy.

Methods

The mRNA expression and genetic alterations of 36 histone acetylation regulators were analyzed in 1599 hepatocellular carcinoma (HCC) samples. The unsupervised clustering method was used to identify the histone acetylation patterns. Then, based on their differentially expressed genes (DEGs), an HAscore model was constructed to quantify the histone acetylation patterns and related subtypes of individual samples. Lastly, the relationship between HAscore and transcription background, tumor clinical features, characteristics of TME, drug response, and efficacy of immunotherapy were analyzed.

Results

We identified three histone acetylation patterns characterized by high, medium, and low HAscore. Patients with HCC in the high HAscore group experienced worse overall survival time, and the cancer-related malignant pathways were more active in the high HAscore group, comparing to the low HAscore group. The high HAscore group was characterized by an immunosuppressive subtype because of the high infiltration of immunosuppressive cells, such as regulatory T cells and myeloid-derived suppressor cells. Following validation, the HAscore was highly correlated with the sensitivity of anti-tumor drugs; 116 therapeutic agents were found to be associated with it. The HAscore was also correlated with the therapeutic efficacy of the PD-L1 and PD-1 blockade, and the response ratio was significantly higher in the low HAscore group.

Conclusion

To the best of our knowledge, our study is the first to provide a comprehensive analysis of 36 histone acetylation regulators in HCC. We found close correlations between histone acetylation patterns and tumor malignant pathways and TME. We also analyzed the therapeutic value of the HAscore in targeted therapy and immunotherapy. This work highlights the interactions and potential clinical utility of histone acetylation regulators in treatment of HCC and improving patient outcomes.

Systemic Treatment for Older Patients with Unresectable Hepatocellular Carcinoma

The incidence rate of hepatocellular carcinoma is growing and age at diagnosis is increasing; however, despite the unprecedented wealth of therapeutic options for advanced HCC, its optimal management in some categories, such as older adults, is yet to be defined. Even though age is not an exclusion criterion per se, most of the landmark trials enrolled a limited number of senior patients, raising some concerns on the potential benefit of active treatments in this group. The identification of more vulnerable patients remains a crucial issue in clinical practice. In fact, the suitability assessment for systemic therapy through performance status metrics might underestimate or conversely overestimate the fitness of older patients, failing to detect other relevant impairments. Thus, the assessment of frailty through geriatric screening scales is largely necessary. In addition, most of the available data relate to the use of sorafenib, while very little is known about the most recent therapeutic agents. Age subgroup analyses provided by many of the pivotal trials did not find significant efficacy or safety differences across ages; however, the most widely used cut-off age of 65 years may not be very informative for the current older population. Regarding immunotherapy, the clinical benefit reported with immune checkpoint inhibitors reassures their safe use in senior patients and supports further investigations to assess their efficacy in this population.