Preclinical use of focal radiation and immune checkpoint blockade to improve therapeutic response in an immunologically cold tumor

AACR Annual Meeting

POSTER | "Preclinical Use of Focal Radiation and Immune Checkpoint Blockade to Improve Therapeutic Response in an Immunologically Cold Tumor" (PDF)

Introduction and Background

• Radiation therapy (RT) is a highly utilized clinical treatment modality with more than 50% of all cancer patients receiving some type of radiotherapy during the course of their illness. Appropriate systems and models to test preclinical radiation combinations are needed.
• In mouse models, radiation treatment has been shown to increase the level of tumor antigen presentation and the variety of peptides available for cross-presentation. Current work in the field focuses on using radiation as a tool to bridge the gap from tumor equilibrium to tumor elimination, which could improve the response rate of immuno-oncology agents.
• 4T1 is a murine breast cancer model known to have a large percentage of myeloid derived suppressor cells (MDSC) making the model resistant to many immunotherapies and is considered an immunologically cold tumor.
• We hypothesized that treatment with focal radiation would sensitize 4T1 tumors to anti-mCTLA-4 treatment.