The Image Comics title has sold well since its launch earlier this year and continues to grow in scope, influencing the creator to expand it.
"More than anything, it was that each issue kept wanting to be longer or I kept feeling like I had more ideas and wanted to spend more time with the characters, and realised I was stopping myself from doing that with an arbitrary structure I'd imposed on myself," Brubaker told Comics Alliance.
Fatale centres on a reporter in 2012 as he is drawn into a struggle with an apparently demonic and immortal mobster when he meets a beautiful woman who has been on the run since 1935.
Brubaker recently concluded his lengthy run on Marvel Comics' Captain America titles following the Marvel Now! creative team shake-up.
Fatale #9 debuted on October 31.