A phase II study of capecitabine plus cisplatin in metastatic triple-negative breast cancer patients pretreated with anthracyclines and taxanes

Background: Cisplatin is an effective agent for triple-negative breast cancer (TNBC) and synergistic activity between cisplatin and capecitabine has been demonstrated by in vitro and in vivo studies. This study was designed as a prospective clinical trial to evaluate the efficacy and safety of capecitabine plus cisplatin (XP) regimen in metastatic TNBC patients pretreated with anthracyclines and taxanes. Patients and Methods: Thirty-three patients with metastatic TNBC who had anthracyclines and taxanes as prior therapy were treated with capecitabine 2000 mg/m² orally on day 1 through 14 plus cisplatin 75mg/m² intravenously on day 1 of a 21-day cycle, followed by capecitabine maintenance medications after a maximum of 6 cycles. The primary end point was objective response rate (ORR) and the secondary end points included progression-free survival (PFS), overall survival (OS) and toxicity profiles. Results: A total of 162 cycles was given. ORR was 63.6%. Median PFS was 8.2 (95%CI: 4.8–11.6) months in the entire population and 10.8 (95%CI: 6.5–15.1) months in responding patients. Median OS was 17.8 (95%CI: 14.4–21.2) months in all enrolled patients and 25.8 (95%CI: 14.6–37.0) months in responding patients. Most adverse events were mild and manageable, with neutropenia and nausea/vomiting as the most common toxicities. Grade 3/4 toxicities included leukopenia (10, 30.3%), neutropenia (10, 30.3%), anemia (2, 6.1%), thrombocytopenia (1, 3.0%), nausea/vomiting (3, 9.1%), hand-foot syndrome (HFS; 1, 3.0%), and sensory neuropathy (1, 3.0%). Conclusions: Capecitabine plus cisplatin demonstrated an excellent activity and an acceptable safety profile in metastatic TNBC patients pretreated with anthracyclines and taxanes.