Locally shot ‘New Mutants’ bumped back to 2019

Maisie Williams, shown in a scene from “Game of Thrones,” stars in the trailer for “The New Mutants.”Helen Sloan/HBO

Fox’s expanding “X-Men” franchise underwent a major release date reshuffling late last week that’s most prominently affecting “The New Mutants.”

The Josh Boone-directed superhero spinoff, shot in Boston, primarily at Medfield State Hospital, from July to September last year, has been delayed 10 months, pushing its release from April 13 to Feb. 22, 2019.

The scale of the move comes as a shock, especially given that the movie’s promotional campaign has been under way for almost a year, and a trailer — which stars “Game of Thrones” actress Maisie Williams and “The Witch” discovery Anya Taylor-Joy — dropped in October. What gives?

One explanation is that the studio didn’t want “The New Mutants” — which is being eyed as a potential series starter for Fox — to play against the studio’s highly anticipated “Deadpool” sequel, moved up during the same announcement from June 1 to May 18. That scheduling tweak would have seen both films in theaters at the same time in certain markets.

Reporters for TheWrap and The Tracking Board, however, pointed to another motivation: It’s not scary enough. The film, about five young mutants discovering their powers as they attempt to escape a secret facility where they’re being held against their will, is billed as a full-blooded superhero horror pic. Test screenings, according to the sites’ insider sources, left executives of the opinion that recutting the film and potentially scheduling reshoots could result in a stronger, scarier end product capable of targeting the same horror audiences that made “Get Out” and “It” major box-office successes last year.