Anlotinib Induces a T Cell–Inflamed Tumor Microenvironment by Facilitating Vessel Normalization and Enhances the Efficacy of PD-1 Checkpoint Blockade in Neuroblastoma

Abstract

◥Purpose: Anlotinib has achieved good results in clinical trials of a variety of cancers. However, the effects of anlotinib on the tumor microenvironment (TME) and systemic immunity have not been reported. There is an urgent need to identify the underlying mechanism to reveal new opportunities for its application in neuroblastoma (NB) and other cancers. Understanding the mechanism will hopefully achieve the goal of using the same method to treat different cancers.Experimental Design: This study used bioinformatics, NB syngeneic mouse models, flow cytometry, RNA-seq, and immunofluorescence staining to explore the mechanisms of anlotinib on the TME, and further explored anlotinib-containing combination treatment strategies.Results: We proved that anlotinib facilitates tumor vessel normalization at least partially through CD4 þ T cells, reprograms the immunosuppressive TME into an immunostimulatory TME, significantly inhibits tumor growth, and effectively prevents systemic immunosuppression. Moreover, the combination of anlotinib with a PD-1 checkpoint inhibitor counteracts the immunosuppression caused by the upregulation of PD-L1 after monotherapy, extends the period of vascular normalization, and finally induces NB regression.Conclusions: To our knowledge, this study is the first to dynamically evaluate the effect of a multitarget antiangiogenic tyrosine kinase inhibitor on the TME. These findings have very important clinical value in guiding the testing of related drugs in NB and other cancers. Based on these findings, we are conducting a phase II clinical study (NCT04842526) on the efficacy and safety of anlotinib, irinotecan, and temozolomide in the treatment of refractory or relapsed NB, and hopefully we will observe patient benefit.

Combination of Anti-PD-1 Antibody, Anlotinib and Pegaspargase “Sandwich” With Radiotherapy in Localized Natural Killer/T Cell Lymphoma

“…Vascular endothelial growth factor (VEGF) has been found to play an important role in systemic and local immunosuppression in tumor models ( 31 ). Increased levels of VEGF in tumor microenvironment could change the expression of adhesion molecules to directly inhibit the function of T cell, prevent T-cell activation, reduce the T cell-mediated anticancer immune response, and promote the recruitment and proliferation of immunosuppressive cells ( 31 , 32 ). As a multitarget antiangiogenic TKI, anlotinib could firstly inhibit the VEGFR to normalize the tumor vessels, reducing tissue hypoxia and enhancing the delivery of other antitumor agents such as immune checkpoint inhibitor ( 32 ).…”

“…Increased levels of VEGF in tumor microenvironment could change the expression of adhesion molecules to directly inhibit the function of T cell, prevent T-cell activation, reduce the T cell-mediated anticancer immune response, and promote the recruitment and proliferation of immunosuppressive cells ( 31 , 32 ). As a multitarget antiangiogenic TKI, anlotinib could firstly inhibit the VEGFR to normalize the tumor vessels, reducing tissue hypoxia and enhancing the delivery of other antitumor agents such as immune checkpoint inhibitor ( 32 ). Secondly, monotherapy of anlotinib was found to upregulate the expression of PD-L1 in the tumor microenvironment (TME), which could increase the antitumor effect of anti-PD-1 antibody ( 31 , 32 ).…”

“…As a multitarget antiangiogenic TKI, anlotinib could firstly inhibit the VEGFR to normalize the tumor vessels, reducing tissue hypoxia and enhancing the delivery of other antitumor agents such as immune checkpoint inhibitor ( 32 ). Secondly, monotherapy of anlotinib was found to upregulate the expression of PD-L1 in the tumor microenvironment (TME), which could increase the antitumor effect of anti-PD-1 antibody ( 31 , 32 ). Finally, anlotinib was identified to reprogram the immunosuppressive TME into an immunostimulatory TME by enhancing the infiltration of immune effector cells and the antigen presentation function ( 20 ).…”

Efficacy and safety of Anlotinib plus PD-1 blockade for the treatment of advanced non-small cell lung cancer: A Retrospective study

“…[17] For instance, anlotinib can reprogram the immunosuppressive tumor microenvironment into an immunotimulatory tumor microenvironment through CD4+ T cells. [18] Moreover, PD-1 blockade can regulate immune cell functions, helping to normalize tumor vessels, thus forming a reinforcing loop between tumor vascular normalization and immune reprogramming for reciprocal regulation. [19] On the basis of this, increasing vivo experiments have illustrated that PD-1 blockade combined with anti-angiogenesis can significantly reduce the volume of tumor, reduce the number of metastases and prolong the survival in tumor bearing mice.…”

Effective low-dose Anlotinib induces long-term tumor vascular normalization and improves anti-PD-1 therapy

“…The combination of Anlotinib and anti-PD-1 therapy has been shown to improve antitumor responses ( 25 , 26 ). A preclinical study indicated that Anlotinib could transiently normalize the tumor vasculature and improve the therapeutic effect of PD-1 blockade ( 27 ). The clinical data of anti-PD-1 treatment concomitant with Anlotinib also showed enhanced antitumor activity in patients with various advanced tumors ( 28 – 30 ).…”