4653 Background: D-based chemotherapy is a burgeoning option for men with advanced HRPC. Alone or in combination with E, D has been shown to improve median survival. In this study we tested the combination of D with two different doses of E in patients (pts) with HRPC to improve response rates and to lower side effects. Methods: 72 metastatic HRPC pts were randomly assigned to receive D (70 mg/m2 IV, d2, q3w) and E (3 × 280 mg/d PO starting 1 day prior to D, for 5 consecutive days) for arm A or E (3 x 140 mg/d PO starting 1 day prior to D, for 3 consecutive days) for arm B. Premedication with oral DX at a total daily dose of 16 mg, in divided doses two times a day was administered in arm A on day 1 to 5 and in arm B on day 1 to 3. Initially, 6 cycles were administered and repeated after significant PSA rise. Pts were monitored for PSA response, time to progression (TTP), survival and toxicity. Results: PSA declines of ≥75%, ≥50% and ≤50% were 36.8%, 55.3% and 44.7% in arm A and 38.2%, 67.6% and 32.4% in arm B, respectively (P = .442). TTP in Arm A and Arm B were 11 months (95% CI, 7–14) versus 14 months (95% CI, 8–19), P = .6911) and overall survival 21 months (95% CI, 6–35) versus 22 months (95% CI, 18–27), respectively, (P = .4149). The primary treatment-related side effects observed in arm A and arm B were granulocytopenia (34% and 29%, P = .663) and thrombotic complications caused by E (four pts (11%) and one pt (3%), respectively, P = .206). Associated baseline factors with overall survival in univariate analysis were ECOG performance status (P < .001), hemoglobin level (P < .001), bone pain (P < .001), and PSA (P < .097) and in multivariate analysis ECOG performance status (95% CI, 2.9–13.9) and bone pain (95% CI, 3.2–20.1), (P < .001). Conclusions: In this randomized phase II study the combination of D and E had substantial activity in HRPC. We did not find a statistically significant difference of higher dose of E in combination with D compared to a lower dose of E and D regarding PSA response, TTP and survival. However, there was a tendency of higher toxicity in the high dose E group. These treatment-related toxicities were mainly hematologic and manageable. The results of this study support the assertion that estramustine is not necessary in docetaxel-based treatment regimens. No significant financial relationships to disclose.
A reassessment of P2X7 receptor inhibition as a neuroprotective strategy in rat models of contusion injury