Immunomodulatory Effects of Current Targeted Therapies on Hepatocellular Carcinoma: Implication for the Future of Immunotherapy.

Multikinase inhibitors with antiangiogenic properties used to be standard therapy for patients with advanced hepatocellular carcinoma (HCC). Recently, several antiangiogenic agents (lenvatinib, cabozantinib, and ramucirumab) have demonstrated antitumor activity for advanced HCC in randomized controlled trials. However, the landscape of drug development for HCC may change dramatically with the advent of immune checkpoint inhibitor therapy, particularly the anti-programmed cell death-1 (anti-PD1) agents. In addition, early-phase clinical trials of combination of anti-PD-1 and antiangiogenic agents have shown very promising anti-tumor activity in patients with advanced HCC. Therefore, the critical research questions at present are whether this combination strategy will be the next generation of standard therapy and which antiangiogenic agents will be the optimal partner for the combination. All of the 4 multikinase inhibitors for HCC (sorafenib, regorafenib, lenvatinib, and cabozantinib) have been reported to have immune modulatory effects. The authors systematically reviewed the pre-clinical evidence of their immune modulatory effects to explore whether these effects were mediated by angiogenesis inhibition or by other "off-target" effects on the tumor microenvironment. Studies of sorafenib comprised the majority (58 of the 71) of the research articles reviewed. Potentially beneficial effects on anti-tumor immunity may result from increased M1 polarization of macrophages and stimulation of CD8 T cell function. On the other hand, high dosage of the kinase inhibitors in pre-clinical models and hypoxia associated with angiogenesis may contribute to immune suppression in the tumor microenvironment. Sorafenib and other multikinase inhibitors may promote anti-tumor immunity through modulation of multiple immune cell types as well as the tumor microenvironment. The optimal immune modulatory dosage should be defined to facilitate design of future combination regimens.

Lin YY ，Tan CT ，Chen CW ，Ou DL ，Cheng AL ，Hsu C ... -  《-》

Molecular targeted and immune checkpoint therapy for advanced hepatocellular carcinoma.

Liu Z ，Lin Y ，Zhang J ，Zhang Y ，Li Y ，Liu Z ，Li Q ，Luo M ，Liang R ，Ye J ... -  《-》

CXCR4 inhibition in tumor microenvironment facilitates anti-programmed death receptor-1 immunotherapy in sorafenib-treated hepatocellular carcinoma in mice.

Sorafenib, a broad tyrosine kinase inhibitor, is the only approved systemic therapy for advanced hepatocellular carcinoma (HCC) but provides limited survival benefits. Recently, immunotherapy has emerged as a promising treatment strategy, but its role remains unclear in HCCs, which are associated with decreased cytotoxic CD8(+) T-lymphocyte infiltration in both murine and human tumors. Moreover, in mouse models after sorafenib treatment intratumoral hypoxia is increased and may fuel evasive resistance. Using orthotopic HCC models, we now show that increased hypoxia after sorafenib treatment promotes immunosuppression, characterized by increased intratumoral expression of the immune checkpoint inhibitor programmed death ligand-1 and accumulation of T-regulatory cells and M2-type macrophages. We also show that the recruitment of immunosuppressive cells is mediated in part by hypoxia-induced up-regulation of stromal cell-derived 1 alpha. Inhibition of the stromal cell-derived 1 alpha receptor (C-X-C receptor type 4 or CXCR4) using AMD3100 prevented the polarization toward an immunosuppressive microenvironment after sorafenib treatment, inhibited tumor growth, reduced lung metastasis, and improved survival. However, the combination of AMD3100 and sorafenib did not significantly change cytotoxic CD8(+) T-lymphocyte infiltration into HCC tumors and did not modify their activation status. In separate experiments, antibody blockade of the programmed death ligand-1 receptor programmed death receptor-1 (PD-1) showed antitumor effects in treatment-naive tumors in orthotopic (grafted and genetically engineered) models of HCC. However, anti-PD-1 antibody treatment had additional antitumor activity only when combined with sorafenib and AMD3100 and not when combined with sorafenib alone. Anti-PD-1 treatment can boost antitumor immune responses in HCC models; when used in combination with sorafenib, anti-PD-1 immunotherapy shows efficacy only with concomitant targeting of the hypoxic and immunosuppressive microenvironment with agents such as CXCR4 inhibitors.

Chen Y ，Ramjiawan RR ，Reiberger T ，Ng MR ，Hato T ，Huang Y ，Ochiai H ，Kitahara S ，Unan EC ，Reddy TP ，Fan C ，Huang P ，Bardeesy N ，Zhu AX ，Jain RK ，Duda DG ... -  《-》

Molecular therapies for HCC: Looking outside the box.

Over the past decade, sorafenib has been the only systemic agent with proven clinical efficacy for patients with unresectable hepatocellular carcinoma (HCC). Recently, lenvatinib was shown to be non-inferior to sorafenib, while regorafenib, cabozantinib, and ramucirumab were shown to be superior to placebo in patients failing sorafenib. In addition, trials of immune checkpoint inhibitors reported encouraging efficacy signals. However, apart from alpha-fetoprotein, which is used to select patients for ramucirumab, no biomarkers are available to identify patients that may respond to a specific treatment. Different synergisms have been postulated based on the potential interplay between antiangiogenic drugs and immunotherapy, with several clinical trials currently testing this hypothesis. Indeed, encouraging preliminary results of phase I studies of bevacizumab plus atezolizumab and lenvatinib plus pembrolizumab have led to the design of ongoing phase III trials, including both antiangiogenics and immune checkpoint inhibitors in the front-line setting. Other important phase II studies have tested molecular therapies directed against different novel targets, such as transforming growth factor-beta, MET (hepatocyte growth factor receptor), and fibroblast growth factor receptor 4. These studies integrated translational research with the aim of better defining the biological tumour profile and identifying tumour and blood biomarkers that select patients who may really benefit from a specific molecular therapy. Importantly, good safety profiles make these drugs suitable for future combinations. In this review, we discuss the most recent data on novel combination strategies and targets, as well as looking ahead to the future role of molecular therapies in the treatment of patients with advanced HCC.

Faivre S ，Rimassa L ，Finn RS 《-》

Oral chemotherapy for the treatment of hepatocellular carcinoma.

Yamamoto S ，Kondo S 《-》