Podophyllotoxin inhibitors of topoisomerase ii

A compound of structural Formula I

• or a pharmaceutically acceptable salt thereof, wherein:
• R1 is selected from the group consisting of hydrogen, deuterium, —P(O)(OH)2, —P(O)(OD)OH, and —P(O)(OD)2;
• R2-R3 are independently selected from the group consisting of —CH3, —CH2D, —CHD2, and —CD3;
• R4-R25 and R27-R29 are independently selected from the group consisting of hydrogen and deuterium;
• R26 is selected from the group consisting of —CH3, —CH2D, —CD3, and
• and
• at least one of R1-R29 is deuterium or contains deuterium.