Exelixis has begun a Phase II clinical trial comparing cabozantinib plus abiraterone and prednisone (abiraterone/prednisone) versus abiraterone/prednisone in patients with castration-resistant prostate cancer (CRPC) who have bone metastases and have not been previously treated with chemotherapy. The primary endpoint for the randomized, open-label trial is radiographic progression-free survival (PFS). The trial will compare abiraterone/prednisone against abiraterone/prednisone in combination wit...