Patent ID: 8716295

Claim:
A method for treating colon cancer or human osteosarcoma in a subject, comprising administering to a subject having colon cancer or human osteosarcoma a therapeutically effective amount of a topoisomerase I (TopI) inhibitor and a therapeutically effective amount of (i) a fluoroquinolone derivative that inhibits tyrosyl-DNA-phosphodiesterase 1 (Tdp1) activity, thereby treating the colon cancer or human osteosarcoma in the subject, wherein the TopI inhibitor is selected from camptothecin, irinotecan, topotecan, or saintopin, and wherein the fluoroquinolone derivative comprises or a pharmaceutically acceptable salt or ester thereof, wherein (a) R 1 is cyclopropyl, R 2 is methoxy, R 3 is methyl, and R 4 is wherein each R 5 is methyl; or (b) R 1 is ethyl, R 2 is H, R 3 is H, and R 4 is wherein each R 5 is methyl.