Fox's X-Men drama Hellfire is making a change at the top.

Writers Evan Katz and Manny Coto, who co-created the drama, are exiting, The Hollywood Reporter has learned. Also out are Patrick McKay and John D. Payne, who came up the the story for the drama alongside Katz and Coto and were set to pen the script. A search is under way for a new writer.

The changes come as Hellfire is on a slower development track, insiders say. Hellfire, which previously was considered a live-action X-Men, follows a young special agent who learns that a power-hungry woman with extraordinary abilities is working with a clandestine society of millionaires — known as "The Hellfire Club" — to take over the world.

Sources say the X-Men drama is not likely to go to pilot this season as it remains on a slower track. The change comes as Katz and Coto are shifting their focus to Fox's 24: Legacy, which received a formal pilot order Friday during Fox's time in front of the press at the Television Critics Association's winter press tour. The new take on 24 will feature an entirely new cast with a diverse lead as Fox has high hopes to reboot the franchise for a new era.

The change at the top should not worry diehard fans of the X-Men franchise. Sources say Fox remains committed to Hellfire and wants to get it completely right as the X-Men franchise remains a valuable asset for the company. Should Hellfire go to series and the network renew Batman prequel Gotham, the network would have dramas from both comic book powerhouses DC Comics and Marvel — a first for a broadcast network and something insiders would love to see on their schedule.

As X-Men-themed pilot Legion is being cast, FX already is looking ahead to a series pickup. FX Networks CEO John Landgraf Saturday at TCA said that the potential series is penciled in for a potential launch later this year. Sets are being built and a writers room has been assembled, churning out scripts. While Landgraf cautioned that it is theoretically possible that production or other issues could derail a series pickup of the pilot when it’s completed, he stressed FX’s track record of taking the vast majority of its drama pilots to series, and was confident Legion would continue the trend. “I’m pretty optimistic about Legion,” Landgraf said. “The scripts are extraordinary.”

As for the storyline of Legion, from Noah Hawley, it will not follow the continuity of the films. “It takes place in a parallel universe,” Landgraf said. “The US government is in the early days of being aware of mutants, but not the public. I don’t foresee any characters moving back and forth (between the movies and the series).”

FEBRUARY 04, 2016 11:00am PT by Lesley Goldberg
Dan Stevens, Aubrey Plaza, Jean Smart to Star in FX's 'X-Men' Take 'Legion'

The 'Downton Abbey,' 'Parks and Recreation' and 'Fargo' alums join previously cast Rachel Keller (also from 'Fargo') in the Noah Hawley drama pilot.

FX is going big for its X-Men take Legion.

The network has tapped Downton Abbey's Dan Stevens, Parks and Recreation grad Aubrey Plaza and Fargo alum Jean Smart to star in the pilot from Noah Hawley (Fargo), The Hollywood Reporter has learned.

The Legion pilot introduces the story of David Haller, a man who may be more than human and who has has struggled with mental illness since his teenage years. Diagnosed as schizophrenic, David has been in and out of psychiatric hospitals for years. But after a strange encounter with a fellow patient, he is confronted with the possibility that the voices he hears and the visions he sees might be real. In the comics, David is the son of X-Men founder Charles Xavier (aka Professor X) and Israeli Holocaust survivor Gabrielle Haller. The character first appeared in New Mutants #25 in March 1985.

Stevens will play David. Diagnosed as schizophrenic at a young age, David is a haunted man, trying to find his way back to sanity, but he's getting tired and is about to give up when he meets the girl of his dreams.

Parks breakout Plaza will play Lenny, David's friend, who despite a life of drugs and alcohol abuse, knows that any day now her life is going to turn around — which gives Lenny the likeable energy of the impossible optimist despite her rough demeanor.

Since wrapping NBC's Parks, UCB grad Plaza — who has received multiple offers this pilot season — has focused on film with features Dirty Grandpa, Mike and Dave Need Wedding Dates and Joshy. She next has Mike and Dave Need Wedding Dates. She's repped by CAA, MGMT Entertainment and Schreck Rose.

Smart, who reunites with Hawley after her role in season two of FX's Fargo, is set as Melanie, a nurturing, demanding therapist with a sharp mind and unconventional methods. The actress' role in Fargo earned her a Critics Choice Award for supporting actress in a limited series. The three-time Emmy winner next stars in The Accountant. She's repped by WME and Untitled Entertainment.

Stevens and Plaza join the previously cast Rachel Keller, a Fargo season two breakout who will also reunite with Hawley on Legion. Keller will play the female lead, Syd, a self-sufficient and street smart woman who uses her sharp and prickly demeanor to protect her soft core because even though it makes her a sucker and puts her at risk, she still believes in happily ever after.

Legion hails from FX Productions and Marvel Television, with FXP overseeing production. Hawley, who has an overall with FXP, will write the pilot and serve as an executive producer alongside Lauren Shuler Donner (X-Men: Days of Future Past,Wolverine), Bryan Singer (X-Men: Days of Future Past, Superman Returns), Simon Kinberg (X-Men: Days of Future Past, The Martian) and Marvel Television topper Jeph Loeb (Agents of SHIELD, Daredevil) and Jim Chory (Daredevil). John Cameron is also on board as an exec producer, via his overall deal with FXP, marking his and Hawley's latest collaboration after Golden Globe-winning anthology Fargo. Production on Legion will begin in March.