"Agent X" was born out of Marvel Comics' long-running "Deadpool" series, whose sales had slumped to cancellation point, with experiments including the "miniseries within a series", ("Deadpool: Agent of Weapon X" and "Deadpool: Funeral for a Freak", where the main series' numbering was demoted to secondary status below the "miniseries" numbering), having failed to stymie the leak. The decision was then taken to run a "final arc" to close the series, then restart it from #1 with an X in the title in an attempt to more closely identify it with their popular X-Men franchise (as part of the same effort, "Cable" was changed to "Soldier X" and "X-Force" was changed to "X-Statix"). Rumors circulated amongst fans that the title relaunches at this time (including Deadpool to Agent X) were due in part to a royalty dispute with Rob Liefeld; the rumors were dispelled by Liefeld himself. Online humorist Gail Simone was chosen to write both "Deadpool"'s final arc and the new series, with the UDON studio, who had recently revamped the Taskmaster in a well-received miniseries, to supply the art.