The Conjuring was a huge hit, and it spawned spin-off Annabelle, which was also a huge hit. The Conjuring 2 has kept up the box-office streak, so naturally it’s getting a spin-off flick, too. But instead of being about a haunted object that was peripheral to the main plot, it’ll be about the film’s big antagonist: The Nun.
Source: io9 – The Conjuring 2’s Demonic Nun Is Getting a Spin-Off Movie