The Birds of Prey writer's acclaimed title will end with issue #36.
"On behalf of everyone who worked on this book, I want to thank those readers," wrote Simone on her bendisboard forum page. "In this market, there is no way that a book starring Catman, of all people, should even exist, let alone be the favourite read of so many pros, readers, and critics.
"More comics pros and staffers from all companies told me it was their favourite DC book than anything else I have ever worked on. I think the message was that there was room for outsider comics even during a time when the focus is so intent on the icon characters."
The writer praised DC for allowing her the freedom to take the title where she wished and for allowing her the time to draw the series to a proper conclusion.
"Bane's ambitious plans turn darker and deadlier than anyone imagined, putting the Secret Six in the most perilous position of their nasty little lives," reads the publisher's solicitation for the final issue. "No one escapes unscathed in this one - and the Six won't ever be the same!"
A new Suicide Squad title was announced this week as part of DC Comics' September relaunch. Secret Six is seen as a successor to the older title.
Secret Six #36 will be released on August 3.