A folate receptor-targeting cytotoxic drug conjugate consisting of a folate vitamin analogue linked to a vinca alkaloid microtubule destabilizing agent with potential antineoplastic activity. Mediated through its folate moiety, folate receptor-targeted vinca alkaloid EC0489 delivers the cytotoxic vinca alkaloid moiety directly to cells expressing folic acid receptors, frequently upregulated in many types of tumor cells. After ligand-receptor internalization, the vinca alkaloid moiety binds to tubulin and disrupts microtubule assembly-disassembly dynamics, resulting in cell cycle arrest and apoptosis. The relative tumor cell specificity of this agent reduces the toxicity profile of its vinca alkaloid moiety.