The present invention encompasses a combination of at least one conjugate and one or more chemotherapeutic agent(s) which when administered exerts an unexpectedly enhanced therapeutic effect. The therapeutic effectiveness of the combination is greater than that of the conjugate alone or the administration of one or more of the drug(s) without the conjugate. The present invention is also directed to compositions comprising at least one conjugate and at one or more of chemotherapeutic agent and to methods of treating cancer using at least one conjugate and at least one or more of chemotherapeutic agent (s). The present invention also provides methods of modulating the growth of selected cell populations, such as cancer cells, by administering a therapeutically effective amount of one or more chemotherapeutic agent(s) and at least one conjugate. In each case, such combination has therapeutic synergy or improves the therapeutic index in the treatment of cancer over the anticancer agent(s) alone.
