A phase I and pharmacokinetic study with 21-day continuous infusion of epirubicin.

ABSTRACT

A phase I study with continuous administration of epirubicin for 21 days using a venous access port and a portable pump was performed. The first dose step was 2 mg/m2/d for 21 days. Interval between courses was 3 weeks. Dose increment per step was 1 mg/m2/d. Twenty-two patients entered the study and received a total of 58 courses with a median of two (range, one to nine). Up to 5 mg/m2/d no toxicity (according to World Health Organization [WHO] criteria) occurred. At 6 mg/m2/d (six pts), one patient had leukopenia grade 3. Two others had some hair loss. At 7 mg/m2/d (four patients), all patients developed mucositis (two grade 3). Three patients had bone marrow depression (one grade 3 anemia, one grade 4 leukocytopenia), and one patient developed the hand-foot syndrome. No other toxicity occurred in the patients. One patient obtained a partial response (18 weeks), ten had stable disease (12 to 54 weeks), seven had progressive disease, and four were not evaluable for response. One patient developed cellulitis around the port, responding to antibiotic treatment; one patient developed a vena cava superior syndrome that resolved with urokinase and removal of the access port. No septicemia occurred. Pharmacokinetic studies were performed by high-performance liquid chromatography (HPLC) with fluorometric detection. Plasma steady state was reached after 57 hours. During steady state there was a linear relationship between epirubicin dose administered and epirubicin level in plasma (r = .58, P less than .05), whole blood (r = .75, P less than .005), and in leukocytes (r = .68, P less than .05). The area under the curve in leukocytes was higher with continuous infusion of 6 mg/m2 for 21 days compared with bolus injection of 80 mg/m2. This method of continuous infusion with epirubicin may be a way to increase intracellular drug-uptake as expressed by intracellular area under curve (AUC). We recommend 6 mg/m2/d for 3 weeks for evaluation of antitumor efficacy in phase II studies.