Background: Docetaxel administered every three weeks is the standard treatment for advanced hormone-refractory prostate cancer (HRPC). However, biweekly administration might be better tolerated due to the reduced peak drug concentrations. Therefore, we compared biweekly to triweekly docetaxel as first- or second-line chemotherapy for advanced HRPC in this prospective randomized multicenter trial.
Patients and methods: In this study, 360 patients were randomly allocated to receive docetaxel 75 mg/m(2) i.v. d1 q3 weeks (tT) or 50 mg/m(2) i.v. d1 and d 14, q4 weeks (bT) from March 2004 to May 2009. Oral prednisolone (10 mg/day) was administered in both groups. The groups were well balanced according to the WHO performance status in terms of mean age (70 vs. 68, range 45-87 years) and median serum PSA level at the time of study entry (109 vs. 98 μg/l, range 11-1490 μg/l). The primary endpoint was time to treatment failure (TTF). ClinicalTrials.gov study identifier: NCT00255606.
Results: Ultimately, 158 patients (tT=79; bT=79) were included in this preplanned interim safety analysis; 567 and 487 cycles (equivalent to 1701 and 1948 weeks of treatment) were administered in the tT and bT groups, respectively. The most common grade 3-4 adverse events (expressed as %/cycles) in tT /bT were neutropenia 20%/14%; infection with/without neutropenia 8%/3%; fatigue 3%/3%; febrile neutropenia 2%/1%; and bone pain 2%/1%. Serious adverse events occurred more frequently in the group tT (n=60, 10.6% of cycles) than in the group bT (n=29, 6.0%, p=0.012). One patient died due to coronary infarction, and another was diagnosed with acute lymphocytic leukemia (both in the bT group). Thirty patients (38%) in the bT group and 22 patients (28%) in the tT group were still receiving treatment at 6 months (p=0.176).
Conclusion: Biweekly docetaxel was tolerated better than conventional triweekly with fewer serious adverse events and more patients were still on the therapy at 6 months. Biweekly docetaxel therapy might be considered as an option for elderly patients exhibiting a compromised general condition.