It is currently unknown whether this film will be based on the novel or musical (Itself an adaptation of the novel).
Note from Assistant to Stephen Schwartz: While it looks likely that a movie will one day be made based on the musical WICKED, it most likely will not happen for several years at the very soonest.
After two decades as one of the most beloved and enduring musicals on the stage, Wicked makes its long-awaited journey to the big screen as a spectacular, generation-defining cinematic event this holiday season.