Magnetic Resonance Imaging in Measuring the Effect of Cabozantinib in Patients With Castrate Resistant Prostate Cancer

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.

Inclusion Criteria:

- Histologically or cytologically confirmed prostate cancer with progressive disease

- Evidence of castration resistance defined as disease progression despite a
testosterone level < 50ng/dL (or surgical castration)

- Evidence of metastatic disease to the bones within the lumbar spine, sacrum, or pelvic
bones that is identifiable on screening pelvic MRI

- If patient has had prior pelvis radiation therapy (RT), then bone metastases must be
out of radiated port (e.g. lumbar or sacral spine)

- Any prior therapy for castrate disease acceptable other than prior XL184 with a
minimum washout of 28 days for any other anticancer therapy

- Patients with castrate resistant disease post antiandrogen therapy/withdrawal must
meet at least one of the following criteria:

- Have not received docetaxel chemotherapy

- Have received docetaxel chemotherapy but received less then 225mg/m2 cumulative
dose

- Have documented liver metastases

- Have no pain or pain that does not require a long acting (SR) narcotic

- Have received mitoxantrone chemotherapy in the past for CRPC

Exclusion Criteria:

- Patients who have had chemotherapy or radiotherapy within 4 weeks prior to entering
the study

- Patients who are receiving any other investigational agents

- Prior treatment with other vascular endothelial growth factor (VEGF) or c-MET targeted
therapies

- History of hematemesis or hemoptysis

- The subject has uncontrolled or significant intercurrent illness

- The patient requires concomitant treatment, in therapeutic doses, with anticoagulants