SOUTH SAN FRANCISCO, Calif.--(BUSINESS WIRE)--Exelixis Inc. (NASDAQ:EXEL) today announced the initiation of a phase 1 dose-finding trial of cabozantinib in combination with abiraterone in men with metastatic castration-resistant prostate cancer (CRPC) who have disease progression following treatment with up to two prior chemotherapy regimens. The study is designed to define the maximum tolerated dose (MTD) of cabozantinib in combination with abiraterone and prednisone. Abiraterone was approved by the FDA in April 2011 and is indicated in combination with prednisone for the second-line treatment of CRPC in men who have received prior chemotherapy containing docetaxel. The study is being led by Dr. Chris Sweeney at the Dana-Farber Cancer Institute. The Massachusetts General Hospital and Beth Israel Deaconess Medical Center will also participate in accrual to the study.