Potentiation of immune checkpoint blockade with a pH-sensitizer as monitored in two pre-clinical tumor models with acidoCEST MRI.

Background: Tumor acidosis causes resistance to immune checkpoint blockade (ICB). We hypothesized that a "pH-sensitizer" can increase tumor extracellular pH (pHe) and improve tumor control following ICB. We also hypothesized that pHe measured with acidoCEST MRI can predict improved tumor control with ICB.