Phase III studies of single-agent docetaxel in patients with metastatic breast cancer who have progressed despite previous chemotherapy regimens: preliminary results.

A recent large phase III trial has for the first time demonstrated that choice of treatment can influence survival duration in patients with metastatic breast cancer who have progressed despite previous anthracycline-containing therapy. In a multicenter study, patients who received docetaxel (Taxotere; Rhône-Poulenc Rorer, Antony, France) experienced a longer median survival time (II.4 months v 8.7 months; P = .0097) as well as a longer time to progression (19 weeks v II weeks; P < .001) and higher overall response rate (30% v II.6%; P < .0001) than patients receiving treatment with mitomycin C and vinblastine. The toxicity profile was manageable and tolerable for both arms. Evidence for a risk to benefit ratio favoring docetaxel is also provided by a second phase III trial in which docetaxel was compared with doxorubicin in metastatic breast cancer patients who have progressed despite prior alkylating chemotherapy. In these patients, docetaxel was more active than doxorubicin, achieving an overall response at a significantly higher rate (47.8% v 33.3%; P = .008) and in a shorter time (median, 12 weeks v 23 weeks; P = .007). In this study, the duration of survival was not influenced by treatment. However, the higher response rate with docetaxel was achieved without the risk of potentially fatal cardiac toxicity seen in some patients who received doxorubicin. To date, docetaxel is the only single agent shown to have a potential superior activity when compared with doxorubicin in patients with progressive metastatic disease.