If you've ever wondered what happened to the Bryan Singer-produced Hellfire Club TV series that was in the works at FOX back in 2015, now we know. The premise wound up too thin to develop, so it was shelved and redeveloped into The Gifted.
When Fox revealed the Hellfire Club premise a year or so ago, the pitch was focused on a young special agent tracking a woman with mutant powers in the 1960s. The mystery woman would've been involved with a secret society of millionaires intent on world domination. If you've seen X-Men: First Class, then you know this story: Moira MacTaggert (Rose Byrne) tracks Emma Frost (January Jones) into a private club (of millionaires), and events follow from there. It seems the rough pitch for Hellfire Club drew heavily from those scenes for its set-up.
Speaking to the print edition of Entertainment Weekly, Donner explained Hellfire Club didn't really work because "it was too many characters and not enough depth of character.”
It makes sense, then, that Matt Nix's pitch for The Gifted would catch their attention. While there are plenty of characters and a good number of mutants in The Gifted, the show itself focuses on the Reed family, which seems to give FOX and Marvel the grounding point they were looking for to tell a story within this universe. As opposed to just making a show in the universe.