Carbozantinib (Exelixis) enters Phase III for metastatic castration resistant Prostate Cancer

COMET-1 trial is initiated for cabozantinib from Exelixis Inc., and is a double-blind, placebo-controlled Phase III study that will include up to 240 international sites. The trial is designed to enroll 960 patients with metastatic castration-resistant Prostate Cancer (mCRPC) who have previously been treated with docetaxel, and abiraterone acetate and/or MDV3100. All patients will have bone metastases and there is no limit to the number or type of prior treatments. Patients will be randomized 2:1 to receive cabozantinib (60 mg daily, N=640) or prednisone (5 mg twice daily, N=320). Each arm will also receive placebo in order to account for the once-daily versus twice-daily dosing regimens of cabozantinib and prednisone. The primary endpoint for COMET-1 is overall survival in mCRPC patients who have had disease progression after treatment with docetaxel and abiraterone acetate and/or MDV3100. Exelixis expects data from COMET-1 to be available in the first half of 2014.