A semisynthetic taxane; stabilizes microtubule assembly by reducing lag time for tubulin assembly (LT50 = 100 nM) and the rate of cold-induced microtubule depolymerization (IC50 = 100-250 nM) in vitro; has antiproliferative effects comparable to docetaxel in cell lines sensitive to chemotherapy (IC50s = 4-41 and 8-79 nM, respectively); more potent than docetaxel in P-glycoprotein-expressing cell lines with in vitro acquired resistance to taxanes or other chemotherapeutic agents (IC50s = 13-410.4 and 170-4,010 nM, respectively); has antitumor activity against docetaxel-susceptible human gastric carcinoma N87 and docetaxel-resistant B16/TXT melanoma xenografts,