Garber, a Tony nominee for Deathtrap, Little Me, Lend Me a Tenor and Damn Yankees, will co-star opposite Ryan Reynolds in "Selfless," the indie sci-fi thriller from FilmDistrict and Endgame Entertainment that will release in September 2014.
Tarsem will direct the project, which is penned by Alex and David Pastor and centers on a terminally ill billionaire who undergoes a procedure to transfer his consciousness into the body of a younger man. Garber will play the billionaire's longtime friend.
Porter, who currently stars in the Tony-winning musical Kinky Boots, is in negotiations to join Barry Levinson's "The Humbling," which will also feature Al Pacino, Greta Gerwig, Diane Wiest and Mandy Patinkin.
The project, adapted from the Philip Roth novel, features a script by Buck Henry, Michal Zebede and Levinson and centers around a famous stage actor who retires to his upstate New York farmhouse and takes up with a much younger woman.
In other screen news, Tony Award nominee Bertie Carvel (Matilda) has joined the cast of the Danny Boyle-helmed pilot "Babylon," about the people and politics in the command rooms and on the frontlines of a modern police force, for the U.K.'s Channel 4.
Sam Bain and Jesse Armstrong penned the pilot, which Boyle will direct. Also in the cast are Brit Marling, James Nesbitt, Paterson Joseph, Jill Halfpenny, Adam Deacon, Daniel Kaluuya, Jonny Sweet and Andrew Brooke.
The pilot is slated to air in early 2014 with an additional six episodes ordered by the network. Boyle is executive producing with Robert Jones, Armstrong and Bain. Jones and Derrin Schlesinger are producing.