Unraveling the Synergy between Atezolizumab and Bevacizumab for the Treatment of Hepatocellular Carcinoma

Systemic Therapy for Hepatocellular Carcinoma

Systemic therapy for hepatocellular carcinoma has evolved from sorafenib to now include immune checkpoint blockade, either atezolizumab/bevacizumab or durvalumab/tremelimumab, and soon to include camrelizumab/rivoceranib and nivolumab/ipilimumab. Second-line therapy remains predominantly either a multikinase inhibitor or ramucirumab. Areas of development include testing immune checkpoint-based regimens in the adjuvant setting after surgery, ablation, or transarterial embolization. Also of interest are studies for patients with Child-Pugh B liver function and adding new checkpoint molecules to the current standard platforms.

Clinical and Radiologic Predictors of Response to Atezolizumab-Bevacizumab in Advanced Hepatocellular Carcinoma

PURPOSE

This study aimed to identify clinical and radiologic characteristics that could predict response to atezolizumab-bevacizumab combination therapy in patients with advanced hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

This single-center retrospective study included 108 advanced HCC patients with intrahepatic lesions who were treated with atezolizumab-bevacizumab. Two radiologists independently analyzed imaging characteristics of the index tumor on pretreatment computed tomography. Predictive factors associated with progressive disease (PD) at the best response based on Response Evaluation Criteria in Solid Tumors, ver. 1.1 were evaluated using logistic regression analysis. Progression-free survival (PFS) was estimated by the Kaplan-Meier method and compared with the log-rank test.

RESULTS

Of 108 patients with a median PFS of 15 weeks, 40 (37.0%) had PD during treatment. Factors associated with PD included the presence of extrahepatic metastases (adjusted odds ratio [aOR], 4.13; 95% confidence interval [CI], 1.19 to 14.35; p=0.03), the infiltrative appearance of the tumor (aOR, 3.07; 95% CI, 1.05 to 8.93; p=0.04), and the absence of arterial-phase hyperenhancement (APHE) (aOR, 6.34; 95% CI, 2.18 to 18.47; p < 0.001). Patients with two or more of these factors had a PD of 66.7% and a median PFS of 8 weeks, indicating a significantly worse outcome compared to the patients with one or no of these factors.

CONCLUSION

In patients with advanced HCC treated with atezolizumab-bevacizumab treatment, the absence of APHE, infiltrative appearance of the intrahepatic tumor, and presence of extrahepatic metastases were associated with poor response and survival. Evaluation of early response may be necessary in patients with these factors.

Advances in Understanding Hepatocellular Carcinoma Vasculature: Implications for Diagnosis, Prognostication, and Treatment

Hepatocellular carcinoma (HCC) progresses through multiple stages of hepatocarcinogenesis, with each stage characterized by specific changes in vascular supply, drainage, and microvascular structure. These vascular changes significantly influence the imaging findings of HCC, enabling non-invasive diagnosis. Vascular changes in HCC are closely related to aggressive histological characteristics and treatment responses. Venous drainage from the tumor toward the portal vein in the surrounding liver facilitates vascular invasion, and the unique microvascular pattern of vessels that encapsulate the tumor cluster (known as a VETC pattern) promotes vascular invasion and metastasis. Systemic treatments for HCC, which are increasingly being used, primarily target angiogenesis and immune checkpoint pathways, which are closely intertwined. By understanding the complex relationship between histopathological vascular changes in hepatocarcinogenesis and their implications for imaging findings, radiologists can enhance the accuracy of imaging diagnosis and improve the prediction of prognosis and treatment response. This, in turn, will ultimately lead to better patient care.

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.

Safety/efficacy of atezolizumab + bevacizumab during anti-platelet/anticoagulation therapy in unresectable hepatocellular carcinoma

BACKGROUND AND AIMS

This study aimed to determine the safety and efficacy of atezolizumab + bevacizumab therapy in hepatocellular carcinoma patients receiving anti-platelet agents or anticoagulants.

METHODS

Patients were divided into those using (IM out) and those not using (IM in) anti-platelet agents or anticoagulants, who violated the exclusion criteria of the IMbrave150 trial, and were retrospectively examined.

RESULTS

The study included 185 patients (IM in: 157; IM out: 28). For first-line treatment, progression-free survival was 184 days for IM in and 266 days for IM out (p = .136). Overall survival was 603 days for IM in and not reached for IM out (p = .265), with no significant between-group difference. Similarly, there were no significant between-group differences in progression-free survival or overall survival for later-line treatment. Haemorrhagic adverse events of ≥grade 3 were observed in 11 IM in patients and 3 IM out patients. No significant factors associated with haemorrhagic adverse events of ≥grade 3 were identified in the multivariate analysis including IM out classification, whose p value was .547. Regarding thrombotic/embolic adverse events in the IM out group, one case of exacerbation of portal vein thrombosis was observed. No deaths were directly attributable to bleeding events or exacerbations of thrombosis.

CONCLUSION

Atezolizumab + bevacizumab therapy shows similar safety and efficacy in patients receiving and those not receiving anti-platelet agents or anticoagulants; therefore, it can be considered for patients with hepatocellular carcinoma receiving anti-platelet agents or anticoagulants.

Analysis of Immune-Related Adverse Events of Atezolizumab and Bevacizumab in Patients with Hepatocellular Carcinoma: A Multicentre Cohort Study

Introduction

Despite the emergence of atezolizumab and bevacizumab (A + B) as standard first-line systemic therapy for unresectable hepatocellular carcinoma (HCC), a comprehensive understanding of the clinical significance of immune-related adverse events (irAEs) remains limited. We aimed to assess the impact of irAEs on patients with HCC undergoing A + B treatment.

Methods

This multicentre retrospective study included consecutive patients with HCC who were treated with the A + B regimen from September 2020 to December 2022. Patients were categorized into three groups based on the severity of irAEs, ranging from those without any experience of irAEs to those with severe irAEs.

Results

This study included 150 patients with HCC, with a mean age of 63.3 years. Among them, 93.3% of patients were classified as Barcelona Clinic Liver Cancer stage C, 52.0% had portal vein tumour thrombosis (PVTT), and 60.7% extrahepatic spread. Patients were classified as follows: group 1 (n = 84) had no irAEs, group 2 (n = 37) had mild irAEs (grade 1-2), and group 3 (n = 29) had severe irAEs (grade ≥3). The median overall survival (OS), progression-free survival (PFS), and time-to-treatment discontinuation (TTD) were 13.6, 5.7, and 3.6 months, respectively. Group 2 demonstrated significantly superior OS compared to group 1 (9.5 months) and group 3 (5.6 months), with a median OS of 23.0 months (p < 0.001). Furthermore, group 2 demonstrated significantly better outcomes in terms of PFS and TTD compared to both group 1 and group 3 (p < 0.001 for both). Multivariate analysis identified mild irAEs (hazard ratio [HR], 0.353; p = 0.010), ALBI grade 1 (HR, 0.389; p = 0.006), Child-Pugh class A (HR, 0.338; p = 0.002), and the absence of PVTT (HR, 0.556; p = 0.043) as independent predictors of better OS.

Conclusion

Our study highlights the significant impact of irAE severity on the outcomes of patients with HCC receiving A + B. Notably, the occurrence of mild irAEs was independently associated with favourable survival, suggesting their potential role as surrogate indicators of HCC prognosis.

Evolution of Systemic Treatment for Hepatocellular Carcinoma: Changing Treatment Strategies and Concepts

Systemic therapy for hepatocellular carcinoma (HCC) has undergone substantial advancements. With the advent of atezolizumab plus bevacizumab (ATZ/BEV) combination therapy, followed by durvalumab plus tremelimumab, the era of immunotherapy for HCC has commenced. The emergence of systemic treatment with high response rates has led to improvements in overall survival while enabling conversion to radical surgical resection in some patients with HCC. In patients with intermediate-stage HCC, new treatment strategies combining systemic treatment and transcatheter arterial chemoembolization (TACE) are under development in clinical trials. Moreover, the addition of local therapies, such as TACE, to systemic treatment according to the treatment effect could achieve a certain percentage of complete response. In the IMbrave050 trial, the efficacy of ATZ/BEV combination therapy was validated in patients predicted to have a high risk of recurrence, especially in those who had undergone radical surgery or radiofrequency ablation for HCC. Therefore, systemic treatment for HCC is entering a new phase for all disease stages. The objective of this review is to organize the current position of systemic therapy for each HCC stage and discuss the development of new treatment methods and strategies, with a focus on regimens incorporating immune checkpoint inhibitors, along with future prospects.

Efficacy and Safety of Atezolizumab and Bevacizumab in Appendiceal Adenocarcinoma

PURPOSE

Appendiceal adenocarcinoma (AA) remains an orphan disease with limited treatment options for patients unable to undergo surgical resection. Evidence supporting the efficacy of combined VEGF and PD-1 inhibition in other tumor types provided a compelling rationale for investigating this combination in AA, where immune checkpoint inhibitors have not been explored previously.

EXPERIMENTAL DESIGN

We conducted a prospective, single-arm phase II study evaluating efficacy and safety of atezolizumab in conjunction with bevacizumab (Atezo+Bev) in advanced, unresectable AA.

RESULTS

Patients treated with the Atezo+Bev combination had 100% disease control rate (1 partial response, 15 stable disease) with progression-free survival (PFS) of 18.3 months and overall survival not-yet-reached with median duration of follow-up of 40 months. These survival intervals were significantly longer relative to a clinically and molecularly matched synthetic control cohort treated with cytotoxic chemotherapy designed for colorectal cancer (PFS of 4.4 months, P = 0.041).

CONCLUSIONS

In light of recent data demonstrating a lack of efficacy of 5-fluorouracil-based chemotherapy, Atezo+Bev is a promising treatment option for patients with low-grade unresectable AA; further study is warranted.

SIGNIFICANCE

AA remains an orphan disease with limited systemic therapy options for patients who are not candidates for surgical resection. These data suggest activity from combined VEGF and PD-L1 inhibition that warrants further study.

Advances in Immunotherapy for Hepatocellular Carcinoma (HCC)

Hepatocellular carcinoma (HCC) is the second most common cause of cancer-related deaths in the world. More than half of patients with HCC present with advanced stage, and highly active systemic therapies are crucial for improving outcomes. Immune checkpoint inhibitor (ICI)-based therapies have emerged as novel therapy options for advanced HCC. Only one third of patients achieve an objective response with ICI-based therapies due to primary resistance or acquired resistance. The liver tumor microenvironment is naturally immunosuppressive, and specific mutations in cell signaling pathways allow the tumor to evade the immune response. Next, gene sequencing of the tumor tissue or circulating tumor DNA may delineate resistance mechanisms to ICI-based therapy and provide a rationale for novel combination therapies. In this review, we discuss the results of key clinical trials that have led to approval of ICI-based therapy options in advanced HCC and summarize the ongoing clinical trials. We review resistance mechanisms to ICIs and discuss how immunotherapies may be optimized based on the emerging research of tumor biomarkers and genomic alterations.

Mechanisms and therapeutic strategies to combat the recurrence and progression of hepatocellular carcinoma after thermal ablation

Thermal ablation (TA), including radiofrequency ablation (RFA) and microwave ablation (MWA), has become the main treatment for early-stage hepatocellular carcinoma (HCC) due to advantages such as safety and minimal invasiveness. However, HCC is prone to local recurrence, with more aggressive malignancies after TA closely related to TA-induced changes in epithelial-mesenchymal transition (EMT) and remodeling of the tumor microenvironment (TME). According to many studies, various components of the TME undergo complex changes after TA, such as the recruitment of innate and adaptive immune cells, the release of tumor-associated antigens (TAAs) and various cytokines, the formation of a hypoxic microenvironment, and tumor angiogenesis. Changes in the TME after TA can partly enhance the anti-tumor immune response; however, this response is weak to kill the tumor completely. Certain components of the TME can induce an immunosuppressive microenvironment through complex interactions, leading to tumor recurrence and progression. How the TME is remodeled after TA and the mechanism by which the TME promotes HCC recurrence and progression are unclear. Thus, in this review, we focused on these issues to highlight potentially effective strategies for reducing and preventing the recurrence and progression of HCC after TA.

ROS in hepatocellular carcinoma: What we know

Hepatocellular carcinoma (HCC), which is a primary liver cancer subtype, has a poor prognosis due to its high degree of malignancy. The lack of early diagnosis makes systemic therapy the only hope for HCC patients with advanced disease; however, resistance to drugs is a major obstacle. In recent years, targeted molecular therapy has gained popularity as a potential treatment for HCC. An increase in reactive oxygen species (ROS), which are cancer markers and a potential target for HCC therapy, can both promote and inhibit the disease. At present, many studies have examined targeted regulation of ROS in the treatment of HCC. Here, we reviewed the latest drugs that are still in the experimental stage, including nanocarrier drugs, exosome drugs, antibody drugs, aptamer drugs and polysaccharide drugs, to provide new hope for the clinical treatment of HCC patients.