Of course, it is common for movies to make changes to book products, often to show something that is explained in the books or to streamline the story in some way, but we already know IT’s changes will need to go quite a bit further, namely because the book shifts between the adults and the kids in The Losers Club and the movie will only focus on the kids, with a sequel already being planned.
That’s right, Stephen King, a busy writer and businessman, went out of his way to give the IT creative team the ultimate seal of approval, shooting Andy Muschietti an email explaining that the changes to his original story were OK in his book.