The Intersection between Tumor Angiogenesis and Immune Suppression

Area of Science:

• Oncology
• Immunology
• Pharmacology

Background:

• Immune checkpoint inhibitors (ICI) and antiangiogenesis agents represent significant advancements in cancer therapy.
• Antiangiogenesis agents are effective in highly vascularized tumors, while ICIs primarily benefit immunologically inflamed tumors.
• Overcoming resistance in non-inflamed tumors and the immunosuppressive tumor microenvironment remains a key challenge for ICI development.

Purpose of the Study:

• To explore the synergistic effects of combining antiangiogenesis agents with immune checkpoint inhibitors (ICI).
• To understand how this combination therapy can overcome immune suppression and resistance in various cancer types.
• To highlight the clinical significance of combining these therapeutic modalities.

Main Methods:

• Review of existing clinical data and research on the combination of antiangiogenesis agents and ICIs.
• Analysis of the mechanisms by which angiogenesis factors contribute to immune suppression.
• Examination of the impact of these combinations on tumor response and patient outcomes.

Main Results:

• Angiogenesis factors promote immune suppression by impairing antigen-presenting cells and effector cells, and by augmenting regulatory T cells (Treg), myeloid-derived suppressor cells (MDSC), and tumor-associated macrophages (TAM).
• These suppressive immune cells can, in turn, promote angiogenesis, creating a detrimental cycle.
• The combination of bevacizumab and ipilimumab was the first to demonstrate the potential of this dual approach, with numerous similar combinations now in clinical use.

Conclusions:

• The combination of antiangiogenesis agents and ICIs offers a promising strategy to enhance cancer treatment efficacy.
• This approach effectively targets both tumor vascularization and the immunosuppressive microenvironment.
• The successful clinical translation of these combinations underscores their therapeutic value.