Trial watch: immunotherapeutic strategies on the horizon for hepatocellular carcinoma

A landscape of checkpoint blockade resistance in cancer: underlying mechanisms and current strategies to overcome resistance

The discovery of immune checkpoints and the development of immune checkpoint inhibitors (ICI) have achieved a durable response in advanced-stage cancer patients. However, there is still a high proportion of patients who do not benefit from ICI therapy due to a lack of response when first treated (primary resistance) or detection of disease progression months after objective response is observed (acquired resistance). Here, we review the current FDA-approved ICI for the treatment of certain solid malignancies, evaluate the contrasting responses to checkpoint blockade in different cancer types, explore the known mechanisms associated with checkpoint blockade resistance (CBR), and assess current strategies in the field that seek to overcome these mechanisms. In order to improve current therapies and develop new ones, the immunotherapy field still has an unmet need in identifying other molecules that act as immune checkpoints, and uncovering other mechanisms that promote CBR.

Similar usage of T-cell receptor β-chain between tumor and adjacent normal tissue in hepatocellular carcinoma

BACKGROUND

In this study, we comprehensively profiled the T-cell receptor (TCR) repertoire of the tumor and adjacent normal tissue in patients with HBV-associated hepatocellular carcinoma (HCC) and determined the baseline characteristics and clinical significance of TCR.

METHODS

High-throughput sequencing was used to determine the profile of complementarity-determining region 3 (CDR3) of the TCR-β chain variable (TRBV) in the tumor and normal tissue samples of 14 HCC patients. At the same time, TRBV diversity and differences in expression between tumor and normal tissues were investigated. The cumulative frequency of top 100 CDR3 (CF100), clonality, and Shannon entropy as indices to evaluate diversity, RESULTS: The diversity of TRBV CDR3 showed no significant difference between tumor and normal tissues. Of the 58 V gene segments in TRBV, TRBV16 and TRBV7-6 had a significantly higher frequency in the tumor group than in the normal group (p < 0.05). The frequency of 14 J gene segments showed no significant difference between tumor and normal tissues. In contrast, the frequency of 22 TRBVx/BJx combinations was significantly higher in the tumor than in the normal tissue. In addition, the length and type of TRBV CDR3 were similar in tumor and normal tissues, and a Gaussian distribution was observed in both groups.

CONCLUSION

This study provided a large amount of information about the TCR lineage in HBV-associated HCC, laying the foundation for further research. In addition, the fact that the immune repertoire (TRBV CDR3) hardly differs between tumor and adjacent normal tissue provides a new clue for exploring the mechanism of the liver as an organ with immune privileges.

The rapidly evolving landscape of HCC: Selecting the optimal systemic therapy

Over the past years, there has been a remarkable advance in the systemic treatment options for advanced HCC. The overall survival has gradually increased over time, with larger benefits for patients with sensitive tumors and preserved liver function, the latter being an essential condition for the delivery of sequential lines of treatment and optimization of clinical outcomes. With the approval of new first-line agents and the introduction of immune checkpoint inhibitor-based therapies, the treatment landscape of advanced HCC is becoming wider than ever. Atezolizumab plus bevacizumab and, more recently, durvalumab plus tremelimumab have entered the clinical practice and are the current standard of care for treatment-naïve patients, surpassing sorafenib and lenvatinib monopoly. As no head-to-head comparisons are available among all the first-line treatment options, the recommendation for the most appropriate choice and sequence is patient-driven and integrates efficacy data with clinical comorbidities, background liver disease, and the safety profile of available drugs. In addition, predictive biomarkers for successful patients' stratification are yet to be available and constitute the focus of ongoing research. The treatment algorithm is likely to become even more complex since systemic therapeutic approaches are now being translated into earlier stages of the disease, with an impact on the evolution of the sequential treatment of patients with HCC.