Gemcitabine and paclitaxel in metastatic breast cancer: a review

Gemcitabine (Gemzar) and paclitaxel are active drugs in the treatment of metastatic breast cancer. Phase I clinical trials data have suggested that the gemcitabine plus paclitaxel combination is safe in breast cancer patients. Two doses/administration schedules have been preferred in subsequent phase II and III trials: gemcitabine on days 1 and 8 plus a taxane on day 1, every 3 weeks; or gemcitabine plus a taxane on days 1 and 14, every 4 weeks. In phase II trials, 114 of 221 patients (52%) responded to gemcitabine/paclitaxel therapy. Response rates were lower among patients who received previous chemotherapy for metastatic disease (response rates: 45%, second line and 70%, first line). Toxicity of gemcitabine/paclitaxel regimens has generally been low, with few cases of neutropenia or nonhematologic toxicity. Results of the randomized phase III registration trial show a clear advantage for gemcitabine plus paclitaxel over paclitaxel alone in time to disease progression, objective response, and overall survival. Triplet combinations, in which an anthracycline is added to gemcitabine/paclitaxel, are being explored in the metastatic and neoadjuvant settings.