A genetically engineered epothilone analog with potential antineoplastic activity. Upon administration, epothilone analog UTD1 binds to tubulin, induces microtubule polymerization and stabilizes microtubules against depolymerization, which may result in the inhibition of cell division, the induction of G2/M arrest, and apoptosis. Compared to first-generation epothilones, this agent exhibits greater safety and enhanced activity against certain multidrug-resistant (MDR) tumors.