Cabozantinib, TKI, for metastatic castration resistant prostate disease.

For metastatic castration resistant prostate cancer, many new options are becoming available, such as androgen receptor targeted agents such as abiratone, enzalutamide, plus other novel drugs such as sipulecel-T, and cabazitaxel. An oral TKI, called Cabozantinib, has activity against VEGF2 and mesenchymal-epithelial transistion factor (MET)- both of which are expressed in CRPC. A phase II trial, 171 CRPC patients, those with stable disease after one regimen of chemo were randomly assigned to cabozantinib or placebo. Patients on cabozantinib has higher median PFS, 23.9m vs 5.9months. and had better resolution of bone improvements as seen on bone scan. Toxicity of cabozantinib were like other TKI which inc fatigue, weight loss, hand-foot syndrome, which led to reduction of dose in 60% of patients. Due to the striking change in bone scans of phase II patients, Phase III trials are in progress studing affects of cabozantinib vs either mitoxantone and prednisone or prednisone alone in order to access pain and bone scan responses. Ref- Smith D. C., et al. (2013). Cabozantinib in patients with advanced prostate cancer: results of a phase II randomised discontinuation trial. Journal of Clinical Oncology, 31, 412.