HANNOVER, Germany-Epirubicin (Ellence)/paclitaxel (Taxol) as first-line treatment significantly slows progression of metastatic breast cancer, compared with epirubicin/cyclophosphamide. Interim results of a multicenter phase III trial comparing the two regimens were reported by Hans-Joachim Luck, MD, of the Medical University, Hannover, Germany, at the ASCO annual meeting.
HANNOVER, GermanyEpirubicin (Ellence)/paclitaxel (Taxol) as first-line treatment significantly slows progression of metastatic breast cancer, compared with epirubicin/cyclophosphamide. Interim results of a multicenter phase III trial comparing the two regimens were reported by Hans-Joachim Luck, MD, of the Medical University, Hannover, Germany, at the ASCO annual meeting.
Dr. Luck reported that time to progression, the primary study endpoint, was 39 weeks with epirubicin/paclitaxel vs 32 weeks with epirubicin/cyclophosphamide.
Overall survival was not significantly different (38 weeks with epirubicin/paclitaxel vs 26 weeks with epirubicin/cyclophosphamide), but the rate of primary treatment failure during the time on treatment was 11% with epirubicin/paclitaxel vs 24% with epirubicin/cyclophosphamide (P = .003).
Response rates were also not significantly different. Complete responses occurred in 8% of patients on epirubicin/paclitaxel and 6% on epirubicin/cyclophosphamide, and the overall response rates were 46% vs 40%.
The trial enrolled patients with histologically proven metastatic breast cancer who had no prior chemotherapy and not more than one prior hormonal therapy for metastatic disease.
About one-third of patients had prior treatment with cyclophosphamide/methotrexate/fluorouracil (CMF), which is often used in Germany for this indication, and about 40% had prior adjuvant endocrine therapy.
Patients were randomized to treatment either with epirubicin at 60 mg/m² and paclitaxel at 175 mg/m² or with epirubicin at 60 mg/m² and cyclophosphamide at 600 mg/m². Cycles repeated every 21 days. Dr. Luck said that the delivered dose intensity was 59.6 mg/m² for epirubicin and 173.3 mg/m² for paclitaxel.
For this interim analysis, 489 patients were evaluable for toxicity and 481 for response. Median follow-up was 36 weeks.
There was more hematologic toxicity with epirubicin/cyclophosphamide, but no febrile neutropenia was observed. Cardiotoxicity occurred in less than 1% of patients. Neutropenia was the most common toxicity, and grade 3-4 neutropenia occurred in 34% of patients receiving epirubicin/paclitaxel and 45% of patients receiving epirubicin/cyclophosphamide.
Dr. Luck concluded that the epirubicin/paclitaxel regimen was associated with a lower rate of primary progression, although not with increased overall survival. He reported that patients with previous adjuvant chemotherapy (primarily CMF) had significantly better progression-free survival with epirubicin/paclitaxel than with epirubicin/cyclophosphamide.
In discussing this study, Clifford Hudis, MD, of Memorial Sloan-Kettering Cancer Center, said, It doesnt strike most of us that there is a major difference in progression-free survival between 32 weeks on epirubicin/cyclophosphamide and 39 weeks with epirubicin/paclitaxel...Theres probably a lot less here than meets the eye.
Dr. Hudis suggested that a more useful approach to test might be doxorubicin/cyclophosphamide or epirubicin/cyclophosphamide followed by a taxane.