Magnetic Resonance Molecular Imaging of Patient-Derived Xenografts with MT218

Motivation: Triple negative breast cancer (TNBC) is an aggressive form of breast cancer that often metastasizes early. Early and accurate diagnosis is imperative for improving TNBC patient management and survival. Goal(s): We aim to evaluate MT218, an MRI contrast agent targeting extradomain-B fibronectin in the tumor extracellular matrix, in more clinically relevant small animal models. Approach: Using NSG mice bearing TNBC PDX xenografts, we performed MRI of tumors after administration of MT218 at doses significantly lower than the clinical dose. Results: Both low doses of MT218 demonstrated significant tumor-specific enhancement and facilitated the delineation of tumor boundaries for effective MRI of TNBC. Impact: We demonstrate that MT218 can effectively enhance patient-derived xenograft tumors of triple negative breast cancer, a clinically relevant tumor model, further supporting the clinical translation of MT218 for magnetic resonance molecular imaging of cancer.