Compositions and methods for treating cancer

A protected anti-neoplastic agent of the formula Hyp-N, wherein

• Hyp is a hypoxic activator having the formula:
• wherein R1 is C1-C6 alkyl or C1-C6 alkoxy;
• R2 is hydrogen;
• R3 is —H or C1-C6 alkyl;
• and
• R4 is —H, C1-C6 alkyl, or C1-C6 alkoxy;
• and N is an anti-neoplastic agent, wherein the anti-neoplastic agent is selected from the group consisting of doxorubicin, daunorubicin, duocarmycin, etoposide, duetoposide, Combretastatin A-4, vinblastine, vincristine, camptothecin, topotecan, 5-fluorouracil, AQ4N, hydroxyurea, maytansines, enediyenes, discodermolides, epothilones, taxanes, calicheamicins, tedanolides, bleomycins, calicheamicins, colchicine, cytarabine, dacarbazine, dactinomycin, discodermolides, epirubicin, fludarabine, hydroxyureapentostatin, 6-mercaptopurine, methotrexate, mitomycin, mitoxantrone, carboplatin, cisplatin, prednisone, procarbazine, taxanes, docetaxel, paclitaxel, tedanolides, teniposide, 6-thioguanine, vinca alkaloids, cyclophosphamides, platinum coordination complexes, anthracenediones, and an alkylating agent;
• and N is bonded to Hyp by an —O— group in N.