Immunotherapy Sensitiziation via Tumor Acidosis Mitigation by Esomeprazole Monitored with MRI

Motivation: Biomarkers to predict immunotherapy response are needed. AcidoCEST MRI and hyperpolarized magnetic resonance spectroscopy (HP-MRS) may predict response. Goal(s): Establish baseline pHe and lactate to pyruvate ratio in tumors with varying immunotherapy response. Observe changes after combination treatment with esomeprazole and immune checkpoint blockade (ICB). Approach: AcidoCEST MRI and HP-MRS were used to measure extracellular pH (pHe) and lactate to pyruvate ratio. Imaging was performed on treated and untreated groups. Results: Baseline lactate to pyruvate ratio and pHe were higher in the most resistant model compared to other models, but were unchanged in treatment vs control groups for the most resistant model. Impact: Robust clinical tools are sorely needed to predict immunotherapy response. Development of a non-invasive clinical imaging tool would allow for less wasted time trying ineffective medications and more personalized treatment plans tailored so treatment is as effective as possible.