Advanced breast cancer. A comparative evaluation of epirubicin and doxorubicin (Adriamycin): Preliminary report of the EORTC breast cancer cooperative group

A preliminary report on an uncompleted Phase III study following results obtained from a Phase II study is presented. In the Phase II study epirubicin 90 mg/m² i.v. every three weeks and doxorubicin (Adriamycin) 75 mg/m² i.v. every three weeks were given, the myelotoxicity expected and found being approximately the same for each group. There were two complete and eight partial responses obtained in the epirubicin group of 31 patients and five complete and five partial responses obtained from the 33 patients on doxorubicin. The median duration of complete response in the epirubicin group was 38 1/2 weeks and 24 weeks for doxorubicin. The overall response rate was 32% for epirubicin and 30% for doxorubicin. In the Phase III study, 30 patients out of 90 have given responses - seven complete, 23 partial. Only two patients on epirubicin and four on doxorubicin had a nadir platelet count below 50,000. With respect to myelotoxicity the dosages of 90 and 75 mg/m² for epirubicin and doxorubicin respectively appeared to be adequate. The antitumour activities of both compounds appear to be equal. Oral toxicity and diarrhoea appear to be slightly less with epirubicin.