Abstract: Compounds and pharmaceutically acceptable salts thereof of Formula I are disclosed. Certain compounds and salts of Formula I are active as Top1 and/or Tdp1 inhibitors. The disclosure provides pharmaceutical compositions containing a compound of Formula I as the only active agent, or optionally containing one or more additional active agents. Methods of using compounds of Formula I to treat cancer are provided in this disclosure. The disclosed compounds of Formula I may be used alone to treat cancer, but may also be used in combination with another active agent, such as a Top1 inhibitor, for example, camptothecin or a camptothecin analogue.