Patent ID: 7951772

Claim:
A method for selectively delivering a therapeutic agent to a tumor cell, comprising: contacting a tumor activated prodrug, W-Z-M, with the tumor cell; and allowing the tumor activated prodrug to be selectively cleaved by a factor secreted by the tumor cell, such that the therapeutic agent is selectively delivered to the tumor cell, wherein said tumor activated prodrug, W-Z-M, comprises a component, M, wherein M is a therapeutic agent, said M being linked to a ligand, W-Z, said ligand comprising an arm, Z, linked to a terminal group, W, wherein linkage in the arm, Z, of the ligand, W-Z, or between the arm, Z, and the component, M, prevents intracellular entry of the compound, W-Z-M, wherein said linkage can be selectively cleaved by a factor or factors secreted by a tumor cell so as to permit entry of the therapeutic agent into said tumor cell, and wherein the terminal group, W, includes β-alanyl, and further wherein M is selected from the group consisting of anthracyclines, including doxorubicin and daunorubicin, folic acid derivatives, vinca alkaloids, calicheamycin, mitoxantrone, methotrexate, cytosine arabinosides (ARA-C), adenosine arabinosides (ARA-A), fludarabine phosphate, melphalan, bleomycin, mitomycin, L-canavanine, taxoids, camptothecin and their derivatives, 9-dimethylaminomethyl-10-hydroxycamphtothecin hydrochloride, and their derivatives, optionally linked to a substituted or unsubstituted amino acid.