Men with CRPC whose disease had progressed on聽1 or 2 previous chemotherapy regimens, including a taxane, were eligible. All participants received oxaliplatin 120 mg/m2 and pemetrexed 500 mg/m2 intravenously every 21 days. The primary end point was response rate; objective responses were determined using Response Evaluation Criteria in Solid Tumors (RECIST), version 1.0, criteria and the Prostate Cancer Working Group (1999) criteria. Secondary end points included progression-free survival and OS.
Forty-seven men received a median of 6 cycles (range, 1-21). The overall response rate was 30% (95% confidence interval [CI], 18%-45%), including 10 men with RECIST responses of the 40 who had measurable disease (25%). Overall, 64% had a prostate-specific antigen (PSA) decline and 74% of men had clinical disease control (partial response or stable disease as their best response). Median progression-free survival was 5.8 months (95% CI, 3.8-7.6), with a median OS of 11.9 months. Six of 15 evaluable patients (40%) experienced a pain response. Nineteen patients (40%) experienced a grade 3 or 4 hematologic toxicity, and 16 (34%) experienced a grade 3 nonhematologic toxicity. One patient died while participating in the study.
Combination oxaliplatin and pemetrexed (PemOx) is an effective and tolerable second- or third-line treatment for men with CRPC.