Epirubicin as a single agent therapy for the treatment of breast cancer--a pharmacokinetic and clinical study.

Sixty women with breast cancer (mean age: 61 years; range 36-78 years) were treated with Epirubicin (4'epi-Doxorubicin), 60 mg m-2, as single drug therapy. The drug was administered as 2 hours' constant rate infusions. The pharmacokinetics of the drug during the first course of treatment was evaluated by measurements of the plasma concentration of Epirubicin at the end of the infusion period. There was a five-fold inter-individual variation of the dose-normalized maximum plasma concentration, which increased with increasing age of the patients. There was no correlation between this pharmacokinetic parameter and degree of obesity. An increase in maximum plasma concentration was associated with an increasing degree of alopecia (p = 0.025). Also the degree of nausea and vomiting showed a tendency to increase with increasing maximum plasma concentration (p = 0.07). Fifty four of the sixty patients entered in the present study were evaluable for clinical response. There was one CR (complete remission). Seventeen patients achieved PR (partial response), and twenty five patients had SD (stable disease). Eleven patients did not respond to treatment. The median maximum plasma concentrations were 322, 316, 336 and 288 ng ml-1 in patients with CR, PR, SD and PD, respectively. The results in the present study showed that 60 mg m-2 of Epirubicin given as a constant rate infusion over 2 hours is a useful alternative to more aggressive combination drug therapy for the treatment of breast cancer.