Phase III trial of liposomal doxorubicin and cyclophosphamide compared with epirubicin and cyclophosphamide as first-line therapy for metastatic breast cancer

Objective: To ascertain the efficacy and tolerability of non-pegylated liposomal doxorubicin (Myocet(TM)) and epirubicin combined with cyclophosphamide in the first-line treatment of patients with metastatic breast cancer. Methods: One hundred and sixty anthracycline-naive metastatic breast cancer patients were randomised to receive Myocet (M; 75 mg/m(2)) or epirubicin (E; 75 mg/m(2)) in combination with cyclophosphamide (C; 600 mg/m(2)), every 3 weeks for up to eight cycles. Outcome measures: Response (overall response = complete + partial response rates), time to disease progression, overall survival and cardiac function (left ventricular ejection fraction). Results: Overall response rates were 46% and 39% for MC and EC treatment, respectively (P=0.42). MC was superior to EC with respect to median time to treatment failure (5.7 versus 4.4 months; P=0.01) and median time to disease progression (7.7 versus 5.6 months; P=0.02). Median survival times were 18.3 and 16.0 months for MC and EC, respectively (P=0.504). Unsurprisingly, given an equimolar comparison, neutropenia and stomatitis/mucositis were significantly more common in patients who received MC. However, there was less injection site toxicity with MC. Both treatments showed a low incidence of cardiotoxicity. Conclusion: Myocet appears to be an acceptable alternative to epirubicin as a first-line treatment for patients with metastatic breast cancer because it combines the dose-effect reliability of doxorubicin with the level of safety provided by epirubicin.