December 4th 2004
This study was designed to evaluate the cardiac safety of the combined treatment of HER2-positive metastaticbreast cancer patients with trastuzumab (Herceptin) plus epirubicin and cyclophosphamide (EC) incomparison with EC alone in HER2-negative metastatic breast cancer patients. Patients included those withmetastatic breast cancer without any prior anti-HER2 treatment, anthracycline therapy, or any other chemotherapyfor metastatic disease. This was a nonrandomized, prospective, dose-escalating, multicenter, openlabel,phase II study in Germany. A control group of 23 patients received EC 90/600 mg/m2 3-weekly for sixcycles (EC90 alone). A total of 26 HER2-positive patients were treated with trastuzumab, or H (2 mg/kg weeklyafter an initial loading dose of 4 mg/kg), and EC 60/600 mg/m2 3-weekly for six cycles (EC60+H); another 25HER2-positive patients received H and EC 90/600 mg/m2 3-weekly for six cycles. Asymptomatic reductions inleft ventricular ejection fraction (LVEF) of more than 10% points were detected in 12 patients (48%) treatedwith EC60 + H and in 14 patients (56%) treated with EC90 + H vs 6 patients (26%) in the EC90 alone cohort.LVEF decreases to < 50% occurred in one patient in the EC60+H cohort and in two patients in the EC90+Hcohort during the H monotherapy. No cardiac event occurred in the cohort with EC90 alone. The overallresponse rates for EC60+H and EC90+H were >60%, vs 26% for EC90 alone. The interim results of this studysuggest the cardiac safety of the combination of H with EC may be greater than that of H with AC (doxorubicin[Adriamycin]/cyclophosphamide); however, studies in larger numbers of patients are warranted. The combinationregimen revealed promising efficacy.