Phase I Trial of Pegylated Liposomal Doxorubicin and Docetaxel in Advanced Breast Cancer

Abstract

PURPOSE: To develop a combination of pegylated liposomal doxorubicin (Doxil; Alza Pharmaceuticals, Palo Alto, CA) and docetaxel (Taxotere; Aventis Pharmaceutical, Parsipanny, NJ) that can be safely used for the treatment of advanced breast cancer. PATIENTS AND METHODS: Forty-one patients with locally advanced (n = 10) or metastatic (n = 31) breast cancer received Doxil (30-, 40-, or 45-mg/m2 intravenous [IV] infusion over 30 to 60 minutes), followed 1 hour later by docetaxel (60 or 75 mg/m2 by IV infusion over 1 hour) in cohorts of three to six patients. Dose-limiting toxicity (DLT) was defined as febrile neutropenia, prolonged neutropenia, or grade 3 to 4 nonhematologic toxicity that occurred during cycle 1. RESULTS: In conjunction with docetaxel 75 mg/m2 every 4 weeks, the MTD of Doxil was 30 mg/m2 and required granulocyte colony-stimulating factor (G-CSF) to prevent febrile neutropenia. Without G-CSF, the MTD was docetaxel 60 mg/m2 and Doxil 30 mg/m2 every 3 weeks; only 1 (7%) out of 15 patients treated at this dose level had cycle 1 DLT. Infusion reactions were common with Doxil with the recommended infusion schedule during the first cycle (55%) but were reduced with a modified schedule (7%). There was no clinically significant cardiac toxicity. Objective response occurred in eight of nine assessable patients with stage III disease and in 16 (52%) of 31 patients (95% confidence interval, 34% to 70%) with stage IV disease. CONCLUSION: The recommended dose and schedule of this combination for further evaluation is Doxil 30 mg/m2 and docetaxel 60 mg/m2 given every 3 weeks without G-CSF. When used with G-CSF, it is Doxil 30 mg/m2 and docetaxel 75 mg/m2 every 4 weeks.