Phase II trial of weekly docetaxel, zoledronic acid and selenium for hormone refractory prostate cancer

Abstract

16113 Background: Treatment options for patients with hormone refractory prostate cancer (HRPC) showed unsatisfactory outcomes. Docetaxel-based combinations could offer more promising and tolerated results especially when zoledronic acid was included. Moreover, preclinical and clinical trials showed that Selenium significantly reduced malignant prostate cell proliferation and the risk of developing prostate cancer. Methods: We conducted a phase II trial associating weekly Docetaxel, Zoledronic acid and Selenium. Eligibility consisted of metastatic prostate adenocarcinoma with objective progression or rising prostate specific antigen levels (PSA) despite androgen deprivation therapy. Zoledronic acid was given at a dose of 4 mg on day 1, Docetaxel (25 mg/m2) on days 1, 8 and Selenium orally at 200 microg once daily for 21-day cycle. Results: Thirty one patients were selected but only twenty-seven were enrolled between August 2005 and November 2007. Median age was 67 years (range 53 to 83). A total of 135 cycles were administered with a median of 6 cycles per patient (2–6 cycles). The major toxicities were grades 1 to 2 anemia (37%), alopecia (7.4%) and motor neuropathy (7.4%). Out of the 27 patients assessed for efficacy, only 4 (15%) had a biologic response (>50% PSA decline). A total of 8 patients (30%) experienced clinical benefit with pain reduction. The median survival time was 15 months (95% CI: 11,19) whereas the median progression time was estimated at 6.5 months (95% CI: 5.0,8.1). Conclusions: Combination of weekly Docetaxel, Zoledronic acid and Selenium is a well tolerated regimen but but with limited efficacy. Adding Selenium to chemotherapy does not seem offering any therapeutic advantage. Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Expert Testimony Other Remuneration sanofi-aventis