Phase II Trial of Loubo^® (Lobaplatin) and Pemetrexed for Patients with Metastatic Breast Cancer not Responding to Anthracycline or Taxanes

Purpose: This phase II study was undertaken to determine the efficacy and safety of Loubo$^{(R)}$ (Lobaplatin) in combination with pemetrexed in treating patients with metastatic breast cancer who failed to respond to anthracycline or taxanes. Patients and Methods: Metastatic breast cancer cases who had previously received an anthracycline and a taxane in either adjuvant or metastatic settings, were enrolled. All patients were recruited from Jiangsu Cancer Hospital and Research Institute, and were treated with Loubo$^{(R)}$ (Lobaplatin) 35 $mg/m^2$ (intravenous; on day 1) and pemetrexed 500 $mg/m^2$ (intravenous; on day 1) every 21 days. Efficacy and side effects were evaluated after at least two cycles of chemotherapy. Results: All eligible 19 patients completed at least 2 cycles of chemotherapy with pemetrexed and lobaplatin, and were evaluable. Overall, 3 (15.8%) patients achieved partial response, 11 (57.9%) stable disease, 5 (26.3%) progression of disease, with no complete remission. Response rate was 15.8%, disease control rate was 42.1%. The median survival time was 10.3 months. Neutrophil suppression occurred in 36.8% of patients who had grade 2 toxicity, and 26.3% had grade 3, 26.4% had grade 4. Thrombocytopenia was encountered as follows: 21.1% grade 2, 15.8% grade 3 and 5.5% grade 4. Incidences of anemia were 10.5% in grade 2, 5.3% grade 3 and 0% grade 4. Only 5.3% of patients required packed red blood cell transfusion. Grade 3 digestive tract toxicity occurred in 5.5% of patients. Other toxicities included elevated transaminase,oral mucositis and skin rashes. Conclusions: The regimen of lobaplatin and pemetrexed is modestly active in metastatic breast cancer patients who failed anthracycline or taxanes, and the toxicity profile suggesting that the doses of chemotherapy should be further modified.