A phase II study of lipoplatin (liposomal cisplatin)/vinorelbine combination in HER-2/neu-negative metastatic breast cancer

We assessed the efficacy and safety of a liposomal cisplatin (lipoplatin) and vinorelbine combination in metastatic breast cancer (MBC). Thirty-five patients were treated. The objective response rate was 53.1% and the median survival time was 22 months. Grade 3/4 neutropenia was observed in 44% of cycles, and febrile neutropenia was seen in 4 patients (11.4%). No grade 3/4 nephrotoxicity or neuropathy was noted. This combination is effective and well tolerated in patients with MBC and it warrants investigation as first-line treatment.

Background: Liposomal cisplatin (lipoplatin) has a mechanism of action similar to that of cisplatin, with reduced toxicities and enhanced or similar efficacy. We wanted to assess the efficacy and safety of a lipoplatin/vinorelbine combination in a phase II clinical trial in metastatic breast cancer (MBC).

Methods: Thirty-five patients with HER-2/neu-negative (HER-2/neu(-)) MBC were enrolled. Lipoplatin 120 mg/m(2) (days 1, 8, and 15) and vinorelbine 30 mg/m(2) (days 1 and 8) were administered in a 21-day cycle.

Results: Thirty-five patients were included in the intent-to-treat (ITT) analysis; 32 patients were evaluable for response. The objective response rate was 53.1%. Complete response (CR) was achieved in 3 patients (9.4%), partial response (PR) was seen in 14 patients (43.8%), stable disease (SD) was obtained in 12 patients (37.5%), and progressive disease (PD) was seen in 3 patients (9.4%). Median time to disease progression was 8 months (range 6-10 months). After a median follow-up of 15.5 months, 18 patients were still alive; the median survival time was 22 months (95% confidence interval [CI], 14-30). A total of 174 cycles were administered. Neutropenia was the most frequent hematologic toxicity, with grade 3/4 neutropenia observed in 44% of cycles. Febrile neutropenia was observed in 4 patients (11.4%). No grade 3/4 nephrotoxicity or neuropathy was noted. Grade 1/2 nephrotoxicity occurred in 8 patients (22.9%) and grade 3 vomiting was seen in 3 patients (8.6%).

Conclusions: The results of this trial reveal that vinorelbine/lipoplatin is effective in treating patients with MBC. This regimen is well tolerated with no grade 3/4 nephrotoxicity or neuropathy. The investigation of this regimen as first-line treatment in MBC is warranted.