Although this movie is about the adults, the kids will be making appearances in some flashback scenes.
Jessica Chastain and Jess Weixler, who play the female leads, are real life best friends.
The members of the Loser's Club from It (2017) were asked whom they wanted to play their adult parts: Finn Wolfhard (Richie Tozier) said Bill Hader, Sophia Lillis (Beverly Marsh) said Jessica Chastain, Chosen Jacobs (Mike Hanlon) said Chadwick Boseman, Jack Dylan Grazer (Eddie Kaspbrak) said Jake Gyllenhaal, Wyatt Oleff (Stanley Uris) said Joseph Gordon-Levitt, Jeremy Ray Taylor (Ben Hanscom) said Chris Pratt and Jaeden Lieberher (Bill Denbrough) said Christian Bale. Wolfhard and Lillis's choices were the only two that ended up being cast.
According to insiders Den of Geek, a script is due to be finished in January 2018.
In April 2018, it was announced that Bill Hader had entered talks to play Richie Tozier. In the same week, Harry Anderson, who played the role in It (1990), had passed away.
James Ransone (Eddie) and Jeremy Ray Taylor (young Ben) share the same birthday: June 2nd.
Jessica Chastain had previously acted in Andy Muschietti's 2013 feature Mama.
The first photo of the new adult cast together was released by the official "It" Twitter account on July 2, 2018.
The Black Spot Nightclub fire, which was intended to appear in Chapter One but was cut due to budget constraints, is planned to be the opening scene of this movie.
The Smokehole scene is also planned to be in the sequel (albeit in a flashback).
Bill Skarsgård (Pennywise) has stated that he had more fun on set during this movie because he was actually able to talk to and hang out with his adult co-stars. Skarsgård had minimal contact with his child co-stars in Chapter One so that they would be more genuinely scared of Pennywise once they saw him.
This is the second Stephen King adaptation released in 2019, following Pet Sematary (2019). "It: Chapter One" was also the second-wide release Stephen King adaptation in 2017, following The Dark Tower (2017).
Marlon Taylor and Jarred Blancard from the 1990 miniseries has expressed interest in reprising their roles as Mike Hanlon and Henry Bowers.
Bill Skarsgard's older brother, Alexander Skarsgard, costarred with James Ransone on HBO's Generation Kill.
Continuing with the extreme coincidence of the number 27, this film is set to be released on September 6, 2019 (9+6+2+0+1+9 = 27). The 1st chapter It (2017) was released on September 8, 2017 (9+8+2+0+1+7 = 27). There's a 27 year age gap between Isaiah Mustafa (Mike Hanlon) and Chosen Jacobs (young Mike) as well as Teach Grant (Henry Bowers) and Nicholas Hamilton (young Henry).