Immunomodulatory effects of regorafenib: Enhancing the efficacy of anti-PD-1/PD-L1 therapy

Regorafenib for patients with progression of advanced hepatocellular carcinoma after treatment with atezolizumab plus bevacizumab: a case series

BACKGROUND

Immunotherapy has reshaped the systemic treatment of hepatocellular carcinoma (HCC), with atezolizumab plus bevacizumab (TA) regimen and regorafenib being the first-line and second-line treatment options for advanced HCC, respectively. However, the efficacy of using the second-line therapeutic agent regorafenib in patients with HCC that has progressed after TA regimen treatment is unknown, and there is a lack of supporting clinical data. The purpose of this case series was to evaluate the clinical efficacy of the second-line therapeutic agent regorafenib in patients with advanced HCC who progressed after treatment with a first-line TA regimen.

CASE DESCRIPTION

This case series included five patients with intermediate to advanced HCC treated with regorafenib after progression on a TA regimen. We retrospectively report the clinical data, clinical outcomes, and adverse events of these five patients. According to modified Response Evaluation Criteria in Solid Tumors (mRECIST), one patient achieved partial response (PR), three patients achieved stable disease (SD), and one patient experienced progressive disease (PD); the disease control rate (DCR) reached 80%, and the objective response rate (ORR) reached 20%.

CONCLUSIONS

In patients with intermediate to advanced HCC who experience disease progression after TA therapy, second-line treatment with regorafenib may be effective in delaying progression and may be associated with better disease control. However, these findings need to be further confirmed in prospective studies with larger cohorts.

Efficacy and safety of radiotherapy combined with anti-angiogenic therapy and immune checkpoint inhibitors in MSS/pMMR metastatic colorectal cancer

PURPOSE

Several studies have demonstrated the effectiveness of anti-angiogenic drugs in combination with immune checkpoint inhibitors (ICIs) in patients with microsatellite stable (MSS) or mismatch repair proficient (pMMR) metastatic colorectal cancer (mCRC). However, whether combination radiotherapy (RT) can further improve the prognosis of mCRC patients after second-line treatment remains to be explored.

METHODS

Retrospective analysis of data from mCRC patients who received anti-angiogenic targeted therapy (TT) and immunotherapy (IT) with or without RT after the failure of standard therapy. Progression-free survival (PFS), overall survival (OS), objective response rate (ORR), disease control rate (DCR), and safety were evaluated.

RESULTS

A total of 82 patients who received TT + IT were analyzed. For RT group (n = 42) versus NRT group (n = 40), ORR was 21.4% (9/42) versus 5.0% (2/40); DCR was 83.8% (35/42) versus 65.0% (26/40). Compared with NRT group, RT improved PFS (median: 5.0 vs. 3.6 months; p = 0.04) and OS (median: 15.2 vs. 7.2 months; p = 0.01). In addition, in the population receiving RT, the PFS of RT sequential/simultaneous TT + IT was superior to TT + IT sequential RT (median: 7.1 vs. 6.2 vs. 3.5 months, p = 0.004). Multivariate analysis suggested RT was an independent prognostic factor for PFS and OS. No treatment-related deaths were reported.

CONCLUSIONS

Compared with TT + IT, RT combined with TT + IT improved survival outcomes in MSS/pMMR mCRC patients, with manageable toxicity. RT sequential/simultaneous TT + IT treatment is expected to be the optimal strategy for MSS/PMMR mCRC.

Immune Cells in the Tumor Microenvironment of Soft Tissue Sarcomas

Soft tissue sarcomas (STSs) are a rare heterogeneous group of malignant neoplasms characterized by their aggressive course and poor response to treatment. This determines the relevance of research aimed at studying the pathogenesis of STSs. By now, it is known that STSs is characterized by complex relationships between the tumor cells and immune cells of the microenvironment. Dynamic interactions between tumor cells and components of the microenvironment enhance adaptation to changing environmental conditions, which provides the high aggressive potential of STSs and resistance to antitumor therapy. Today, active research is being conducted to find effective antitumor drugs and to evaluate the possibility of using therapy with immune cells of STS. The difficulty in assessing the efficacy of new antitumor options is primarily due to the high heterogeneity of this group of malignant neoplasms. Studying the role of immune cells in the microenvironment in the progression STSs and resistance to antitumor therapies will provide the discovery of new biomarkers of the disease and the prediction of response to immunotherapy. In addition, it will help to initially divide patients into subgroups of good and poor response to immunotherapy, thus avoiding wasting precious time in selecting the appropriate antitumor agent.

Mechanism of M2 type macrophage-derived extracellular vesicles regulating PD-L1 expression via the MISP/IQGAP1 axis in hepatocellular carcinoma immunotherapy resistance

BACKGROUND

Hepatocellular carcinoma (HCC) is a prevailing cancer affecting human health. M2 macrophages are essential in mediating immune responses in tumors. This study investigated the action of M2 macrophages in immune escape of HCC.

METHODS

Mitotic spindle positioning (MISP), IQ motif containing GTPase activating protein 1 (IQGAP1) and programmed cell death-1 (PD-L1) levels in primary HCC/tumor-adjacent tissues were determined by Western blot, followed by correlation analysis. M2 macrophage and CD3+CD8+T cell percentages were estimated by flow cytometry. Hep3B and HepG2 cells were treated with M2 macrophage conditioned medium (M2-CM) and M2 macrophage-derived extracellular vesicles (M2-EVs) and/or co-cultured with CD8+T cells, followed by assessment of cell viability and apoptosis. TNF-α and INF-γ levels were measured by ELISA. MISP and IQGAP1 overexpression plasmids were transfected into HCC cells to explore their role in immune escape. The interactions among MISP, IQGAP1, STAT3, and PD-L1 were analyzed by co-immunoprecipitation. The mechanism of M2-EVs in HCC immune escape was verified in nude mice.

RESULTS

MISP/IQGAP1/PD-L1 were upregulated in HCC tissues. MISP negatively-correlated with IQGAP1/PD-L1 and IQGAP1 positively-correlated with PD-L1. M2 macrophages were reduced but CD8+T cells were increased in HCC tissues with high MISP expression. M2-CM or M2-EVs inhibited the killing ability of CD8+T cells, increased HCC cell viability, impeded HCC cell apoptosis, induced CD8+T cell apoptosis, downregulated TNF-α and INF-γ, and upregulated PD-L1. M2-EVs facilitated HCC cell immune escape by potentiating IQGAP1 nuclear translocation and activating STAT3 phosphorylation through MISP downregulation. In vivo experiments further verified the action of M2-EVs through MISP.

CONCLUSION

M2-EVs promote HCC cell immune escape by upregulating PD-L1 through the MISP/IQGAP1/STAT3 axis.

Identification of a tissue resident memory CD8 T cell-related risk score signature for colorectal cancer, the association with TME landscapes and therapeutic responses

Backgrounds: The tissue resident memory CD8 T cell (Trm) constitutes an important component of the local immunity. In the context of malignant tumors, mounting evidence also supports the potential anti-tumor property of this cell subset. Therefore, identification of Trm marker genes and exploration of the causative effect of Trm in shaping tumor microenvironment (TME) heterogeneity might provide novel insights for the comprehensive management of cancer patients. Methods: By dissecting a single T cell transcriptome dataset, we acquired marker genes for Trm, which were latter applied to bulk RNA sequencing profiles of two large colorectal cancer (CRC) patient cohorts downloaded from TCGA and GEO databases. First, colorectal cancer patients were divided into different Trm clusters using consensus clustering algorithm. Then, we established a Trm-related gene (TRMRG) risk score signature and tested its efficacy in predicting prognosis for colorectal cancer patients. Moreover, a sequence of rigorous and robust analyses were also carried out to investigate the potential role of Trm-related gene risk score in tumor microenvironment remodeling and therapeutic utility of it in colorectal cancer treatment. Results: A total of 49 Trm marker genes were identified by analyzing single cell RNA sequencing profiles. First, colorectal cancer patients were successfully classified into two Trm clusters with significant heterogeneity in functional enrichment patterns and tumor microenvironment landscapes. Then, we developed a Trm-related gene risk score signature and divided patients into different risk levels. High risk patients were characterized by attenuated immunogenicity, weakened sensitivity to immunotherapy, as well as adverse clinical outcomes. While low risk patients with advantages in survival exhibited increased immunogenicity, stronger metabolic activity and improved immunotherapeutic responses. Conclusion: Through combinatorial analysis of single cell and bulk RNA sequencing data, the present study identified Trm to play a non-negligible role in regulating the complexity and heterogeneity of tumor microenvironment for colorectal cancer. Moreover, the Trm-related gene risk score signature developed currently was corroborated to be tightly correlated with prognosis and therapeutic responses of colorectal cancer patients, thus exhibiting potential application value for clinical practice.

PD-1/PD-L1 checkpoint inhibitors in advanced hepatocellular carcinoma immunotherapy

Hepatocellular carcinoma (HCC) has a high prevalence and mortality rate worldwide. Sorafenib monotherapy has been the standard of first-line treatment for advanced HCC for a long time, but there are still many shortcomings. In recent years, with the deepening of research on tumor immune microenvironment, researchers have begun to explore new approaches in immunotherapy, and the introduction of immune checkpoint inhibitors has brought fundamental changes to the treatment of HCC. Programmed cell death protein 1 (PD-1) is an immune checkpoint molecule that plays an important role in down-regulating immune system function and promoting tolerance. Programmed cell death ligand 1 (PDL-1) is involved in tumor immune evasion by binding to PD-1, resulting in failure of treatment. Currently, immunotherapy targeting the PD-1/PD-L1 axis has achieved unprecedented success in HCC, but it also faces great challenges, with its low remission rate still to be solved. For most patients with HCC, the PD-1/PD-L1 pathway is not the only rate limiting factor of antitumor immunity, and blocking only the PD-1/PD-L1 axis is not enough to stimulate an effective antitumor immune response; thus, combination therapy may be a better option. In this study, changes in the immune microenvironment of HCC patients were reviewed to clarify the feasibility of anti-PD-1/PD-L1 therapy, and a series of monotherapy and combination therapy clinical trials were summarized to verify the safety and efficacy of this newly developed treatment in patients with advanced HCC. Furthermore, we focused on hyperprogressive disease and drug resistance to gain a better understanding of PD-1/PD-L1 blockade as a promising treatment.