A Phase II Study of Docetaxel Plus Carboplatin in Chemonaive Hormone-Refractory Prostate Cancer (HRPC) Patients

Docetaxel-prednisolone is the current standard in HRPC, based on 2 large randomized trials showing improved survival compared to mitoxantrone-prednisolone. Carboplatin has activity in prostate cancer and the combination of Docetaxel-carboplatin is known to be synergistic and is used with good effect in many cancers. The advantage of using this combination in prostate cancer is suported by clinical data: high response rates of docetaxel-carboplatin-estramustine (with G-CSF support) in a phase II trial (Oh, Halabi, Kelly et al. Cancer. 2003 Dec 15;98(12):2592-8), and additional effect of this combination in prior taxane failures (Oh, George, Tay. Clin Prostate Cancer. 2005 Jun;4(1):61-4). Carboplatin itself has activity and theoretically could target the more hormone resistant clones or neuroendocrine components of the tumor.(Di Sant' Agnese. J Urol. 1994 Nov;152(5 Pt 2):1927-31.) We are studying the combination of docetaxel-carboplatin both given in a weekly, low-dose fashion, without estramustine and without G-CSF. This is expected to be an effective and tolerable treatment for HRPC patients. We will be documenting (to our knowledge) for the first time in this trial the efficacy of the combination given in this particular dose and schedule.