Imagine waiting another two years to see the saga written by Stephen King end in theaters after It was released: Chapter 2. Well, that was going to be the main idea of the movie starring the terrifying Pennywise.
This was explained by the producer of the film, Barbara Muschietti, in a recent interview with Io9:
We try to make two more movies. Then it was decided that we would only make one movie, but clearly, there was a lot of material that Andy Muschietti and our screenwriters have had to adapt
It is not surprising that the possibility of making a trilogy of Pennywise was considered due to the success at the box office of It. However, you can already see in cinemas the final outcome of It starring this time by Jessica Chastain, James McAvoy, Bill Hader, and Isaiah Mustafa, among others.