Dr. Posadas Discusses Cabozantinib in Prostate Cancer

Edwin M. Posadas, MD, FACP, medical director, Urologic Oncology Program, Cedars-Sinai’s Samuel Oschin Comprehensive Cancer Institute, discusses a translational phase II study of cabozantinib in men with metastatic castration-resistant prostate cancer(mCRPC) with visceral metastases with characterization of circulating tumor cells and large oncosomes.

Posadas says cabozantinib is a small molecule inhibitor of the tyrosine kinases c-Met and VEGFR-2 that received FDA approval for the treatment of patients with progressive metastatic medullary thyroid cancer in December 2012. There has been a long-standing interest in using this drug in prostate cancer.

Most agents used in prostate cancer are hormonal, cytotoxic, or immunotherapeutic in nature, Posadas says. Kinase inhibitors have been studied for a long time in prostate cancer, but have shown little clinical activity. Cabozantinib is the first kinase inhibitor to show activity, Posadas says.

Cabozantinib has multiple molecular targets and researchers are still unsure of how it works. A phase II study was developed to understand how the drug is working using blood and tissue samples. Posadas also mentions that some of these patients are strongly benefiting from the agent.