Non-pegylated liposome-encapsulated doxorubicin citrate plus cyclophosphamide or vinorelbine in metastatic breast cancer not previously treated with chemotherapy:a multicenter phase III study.

We conducted a phase III multicenter randomized trial to compare the efficacy of the combination of liposome encapsulated doxorubicin (Myocet(©)) plus either cyclophosphamide (MC) or vinorelbine (MV). Since July 2006, 233 patients affected with metastatic breast cancer were randomized to receive the combination of Myocet (M) 60 mg/m(2) i.v. plus cyclophosphamide (C) 600 mg/m2 on Day 1 of a 21­day cycle (Arm A) or Myocet (M) at 50 mg/m2 plus vinorelbine (V) 25 mg/m2 i.v. on Day 1 and V 60 mg/m2 orally on Day 8 on a 21­day cycle (Arm B). The primary endpoints of the study was time to progression (TTP); secondary endpoints were RR, toxicity and OS. Response was observed in 53/116 (45.7%) evaluable patients of Arm A vs. 51/112 (45.5%) of Arm B, respectively (P=NS). Median TTP was 41 weeks (95% CI, 32­51) and 34 weeks (95% CI, 26­39), for M/C and M/V, respectively (P=0.0234). The difference in median OS was not statistically significant (131 vs. 122 weeks; P=0.107). With regard to toxicity, patients treated with MV showed a slight increase of neutropenia and constipation, as compared to those treated with MC. No clinical signs of cardiotoxicity were observed. The MC combination remains as an unbeaten 'standard' in first line treatment of MBC.