Multicenter phase II trial of Genexol-PM, a Cremophor-free, polymeric micelle formulation of paclitaxel, in patients with metastatic breast cancer

• DOI: 10.1007/s10549-007-9591-y
• Publication Date: 2007-05-02T15:05:13Z
• Authors: Keun Seok Lee; Hyun Cheol Chung; Seock Ah Im; Yeon Hee Park; Chul Soo Kim; Sung-Bae Kim; Sun Young Rha; Min Young Lee; Jungsil Ro
• Keywords: 0301 basic medicine; Breast Neoplasms/pathology; Time Factors; Polymers; Chemistry, Pharmaceutical; Kaplan-Meier Estimate; Polyethylene Glycols; Breast cancer; Paclitaxel/adverse effects; Phytogenic/chemistry; Neoplasm Metastasis; Infusions, Intravenous; Micelles; Drug Carriers; Middle Aged; Phase II; 3. Good health; Polyethylene Glycols/chemistry; Clinical trial; Genexol-PM; Chemistry; Treatment Outcome; Breast Neoplasms/drug therapy*; Paclitaxel/chemistry; Female; Phytogenic/administration & dosage; Intravenous; Adult; Infusions; Paclitaxel; Drug Compounding; Phytogenic/therapeutic use*; 610; Antineoplastic Agents; Breast Neoplasms/mortality; Breast Neoplasms; Drug Administration Schedule; Phytogenic/adverse effects; 03 medical and health sciences; Paclitaxel/administration & dosage; Paclitaxel/therapeutic use*; Humans; Micelles*; Aged; Drug Carriers*; Korea; Antineoplastic Agents, Phytogenic; Polymers/chemistry*; Pharmaceutical

Genexol-PM is a novel Cremophor EL-free polymeric micelle formulation of paclitaxel. This single arm, multicenter phase II study was designed to evaluate the efficacy and safety of Genexol-PM in patients with histologically confirmed metastatic breast cancer (MBC). Forty-one women received Genexol-PM by intravenous infusion at 300 mg/m2 over 3 h every 3 weeks without premedication until disease progression or intolerability. A total of 331 chemotherapy cycles were administered, with a median of 8 cycles per patient (range, 1-16). Overall response rate was 58.5% (95% CI: 43.5-72.3) with 5 complete responses and 19 partial responses. Thirty-seven patients who received Genexol-PM as a first-line therapy for their metastatic disease showed a response rate of 59.5% (95% CI: 43.5-73.7), and two responses were reported in four patients treated in the second-line setting for their metastatic disease. The median time to progression (TTP) for all patients was 9.0 months (range, 1.0-17.0+ months). Grade 3 non-hematologic toxicities included sensory peripheral neuropathy (51.2%), and myalgia (2.4%). Eight patients (19.5%) experienced hypersensitivity reactions, with grade 3 in two patients. Hematologic toxicities were grade 3 and 4 neutropenia (51.2 and 17.1%, respectively), and grade 1 and 2 thrombocytopenia (22.0%). Notably, no febrile neutropenia was observed. Genexol-PM appears a promising new paclitaxel in view of significant efficacies. Further trials with different dosing schedules, durations of delivery, or in combination with other drugs are warranted.