Docetaxel. A pharmacoeconomic review of its use in the treatment of metastatic breast cancer.

UNLABELLED: Advanced breast cancer has a poor prognosis (median duration of survival about 2 years); thus, treatment options are largely palliative. Recent studies with the taxoids docetaxel and paclitaxel suggest that these agents are effective second-line therapy in patients with metastatic breast cancer. Objective response rates range from 30 to 57% with docetaxel monotherapy in clinical trials in patients with advanced disease who had failed to respond to previous therapy, and the median time to disease progression ranges from 17 to 20 weeks. Currently available pharmacoeconomic data relating to docetaxel in the treatment of women with metastatic breast cancer include a cost-minimisation study and 3 cost-utility studies which relate to the UK, French and US healthcare systems. All analyses compared docetaxel with paclitaxel. Since no direct clinical comparisons of these 2 agents have been performed, model assumptions were based on available, rather than comparative, clinical data. The French model also considered vinorelbine monotherapy as a comparator. Considering direct costs only, costs associated with docetaxel ranged from < 0.3% less to 13% more than those of paclitaxel. When utilities were evaluated, docetaxel was associated with incremental gains versus paclitaxel of 33 and 75 additional days of quality-adjusted health in the UK and US studies, respectively, and 22 additional days of quality-adjusted progression-free survival (QPFS) in the French analysis. Thus, the incremental cost utility of docetaxel versus paclitaxel was an estimated Pounds 2431 per quality-adjusted life-year (QALY) in the UK analysis (1994 values) and US$8615 per QALY in the US analysis (1997 values). The French model found that docetaxel cost 700 French francs less for the extra days of QPFS (1993 costs).
CONCLUSIONS: Cost-utility analyses, compiled in the absence of direct comparative data, show that docetaxel offers utility gains versus paclitaxel in the treatment of metastatic breast cancer. The incremental cost for these gains is within the accepted range for healthcare interventions.