The film stars Angelina Jolie and David Oyelowo as the parents of the brother and sister who go on to become Peter Pan and Alice from Alice in Wonderland. When an older brother dies in a tragic accident, the siblings are forced to choose between home and imagination.
Details on who Mbatha-Raw and Caine will be portraying is being kept under wraps.
Come Away will be directed by Brenda Chapman who is making her live-action debut with the film after helming animated features The Prince of Egypt and Brave. Marissa Kate Goodhill penned the script with Oyelowo producing through his Yoruba Saxon Productions company.
Production is expected to begin this fall in the U.K. and Los Angeles.
Mbatha-Raw was last seen in Disney's A Wrinkle in Time while Caine will next be featured in King of Thieves.