Docetaxel (75mg/m2 q21d) is standard of care for patients with hormone refractory prostate cancer (HRPC). Recent data indicate, that chemotherapeutics given at MTD induce, besides their cytotoxic effects, mobilization of circulating endothelial cells (CEC) and - progenitors (CEP) in drug-free breaks of each cycle. In preclinical models, mobilized CEC/CEP result in tumor vasculogenesis and progression of disease.
We hypothesize that treatment with sunitinib, an anti-angiogenic tyrosine kinase inhibitor, in between 3 weekly docetaxel disrupts CEC/CEP spikes following docetaxel leading to chemosensitization and reduced tumor re-growth in HRPC patients responding to docetaxel.
