Episode VIII isn't out until December, but work is already well underway on the follow-up. British writer, Jack Thorne, has been brought in for rewrites.
Director Colin Trevorrow and his writing partner, Derek Connolly, had been working on the script but according to The Hollywood Reporter Thorne was brought in to provide 'a fresh set of eyes'. There are no reports on how much will be rewritten but one can imagine the pressure they are under to get the final part of this trilogy just right.
Thorne has most recently written for the BBC adaptation of Philip Pullman's His Dark Materials and Channel 4's version of Philip K. Dick's Do Androids dream of Electric Sheep. He also wrote the script for the new Jacob Tremblay / Julia Roberts fil, Wonder, which will be out later this year.
Episode IX is scheduled to begin production in January.