A Phase II Study of Cabozantinib (XL184) Therapy in Castrate Resistant Prostate Cancer (CRPC) With Visceral Metastases
Cabozantinib (XL184), a multi-targeted tyrosine kinase inhibitor, has demonstrated a
powerful clinical phenotype in men with metastatic castrate resistant prostate cancer
(mCRPC) both before and after chemotherapy. This phenotype consists of rapid reduction in
pain (when present) and improvement in bone scans that may or may not be accompanied by
decrease in serum prostate specific antigen (PSA) concentrations. In previous studies of
cabozantinib in advanced prostate cancer, patients with visceral disease have been excluded.
Hence, this protocol creates a unique opportunity to define the activity of this disease in
the population of men with visceral disease - a marker for poorer prognosis in mCRPC.
- To assess the clinical benefit (complete response + partial response + stable disease) of
cabozantinib in patients with mCRPC with visceral metastases.
- To assess the impact of cabozantinib on numbers live circulating tumor cells (CTCs)
using a novel combination of nanofluidic technology and near-infrared heptamethine
- To test the feasibility of measuring variation in gene expression in circulating tumor
cells (CTCs) in response to therapy.
- To determine if there is an impact of cabozantinib on live circulating tumor cell (CTC)
number and patterns of gene expression.
- To measure the impact of cabozantinib on serum HGF (hepatocyte growth factor) and VEGF
(vascular endothelial growth factor) levels in men with metastatic,
castration-resistant prostate cancer (mCRPC).
- To assess the safety and tolerability of lower doses (i.e. doses below 100 mg daily) of
cabozantinib in mCRPC with visceral metastases.
- To collect biospecimens which may be used determine if there are germline genetic
variations that correlate with toxicity.
- To pilot correlations between molecular content between circulating tumor cells (CTCs),
large oncosomes, and tumor tissue.
Endpoint Classification: Efficacy Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Treatment
Clinical benefit rate from cabozantinib (XL184)
Clinical benefit rate is defined as the combination of complete response, partial response, and stable disease as defined by modified Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 and Prostate Cancer Working Group 2 (PCWG2) criteria.
Baseline to 12 weeks after starting therapy
Edwin Posadas, MD FACP
Cedars-Sinai Medical Center Samuel Oschin Comprehensive Cancer Institute
United States: Food and Drug Administration
|Cedars-Sinai Medical Center||Los Angeles, California 90048|