Epidoxorubicin and docetaxel as first-line chemotherapy in patients with advanced breast cancer: a multicentric phase I-II study.

BACKGROUND: The combination of anthracyclines and taxanes is currently considered the first choice chemotherapy in advanced breast cancer (ABC) and considerable emphasis has been placed on programs exploring the safest and most efficient way to integrate these classes of drugs in both the metastatic and, more recently, the adjuvant setting. We report here the overall results of the combination of epidoxorubicin (E) 90 mg/m2 and docetaxel (D) 75 mg/m2 as first-line chemotherapy in ABC. PATIENTS AND METHODS: A total of 70 patients were entered in the initial dose-finding study (20 patients) and in the subsequent extended phase II trial (50 patients). Overall 54% of patients had dominant visceral disease and 57% had at least two metastatic sites. Adjuvant anthracyclines were allowed in the phase II part of the study based on the lack of cardiac toxicity observed in the phase I study at a median cumulative E dose of 480 mg/m2. A maximum of eight cycles of the combination was allowed, and cardiac function was monitored at baseline and after every second course by echocardiography.
RESULTS: Overall, the median number of cycles administered with the combination was 4 (range 3-8). Neutropenia was confirmed to be the main haematological toxicity, with granulocyte colony-stimulating factor (G-CSF) support required in 44% of the cycles. Febrile neutropenia occurred in 12% of cycles of the combination but 52% of the episodes could be managed on an outpatient basis with oral antibiotics. Overall, the median cumulative dose of E, including prior adjuvant anthracyclines, was 495 mg/m2 (range 270-1020 mg/m2). One patient who received adjuvant E together with radiotherapy to the left chest wall developed fully reversible clinical signs of cardiotoxicity and a significant decrease of LVEF to 35% after a cumulative E dose of 870 mg/m2, with four additional patients (6%) developing asymptomatic and transient decline of resting LVEF. The overall response rate (ORR) in 68 evaluable patients was 66% (95% confidence interval (95% CI): 54%-73%). A comparable antitumour activity of 71% was reported in the group of patients with a prior adjuvant chemotherapy with anthracyclines. After an overall median follow-up time of 22 months (range 4-39+), the median time to progression (TTP) was 4.5 months and the median duration of response was 8 months (range 3-16). No pharmacokinetic (Pk) interaction could be demonstrated between E and D when given simultaneously and sequentially with a one-hour interval.
CONCLUSIONS: The combination of E and D in a multiinstitutional setting is an active and safe regimen in poor-prognosis patients with ABC. New combinations and schedules are worth considering in an attempt to further improve disease response and long-term control of the disease.