PRIMARY OBJECTIVES:
I. To determine effect of XL184 on the functional MRI metrics Ktrans and apparent diffusion coefficient (ADC) within castrate resistant prostate cancer bone metastases.
SECONDARY OBJECTIVES:
I. To quantify progression free survival in men with castrate resistant prostate cancer (CRPC) treated with XL184 according to Prostate Cancer Working Group criteria.
II. To correlate and changes in MRI based functional metrics with bone scan, prostate specific antigen (PSA), Response Evaluation Criteria in Solid Tumors (RECIST) response criteria, circulating tumor cells (CTC) number and with changes in pain.
III. To explore c-MET, phospho-c-MET staining on circulating tumor cells as a predictive biomarker for response and duration of response to XL-184.
OUTLINE:
Patients receive cabozantinib orally (PO) once daily (QD). Treatment continues in the absence of disease progression or unacceptable toxicity.
After completion of study treatment, patients are followed up periodically.
