
Iñarritu, the creator of films such as "Amores Perros", "21 Grams", "Babel" and "Biutiful", said he was thrilled "to have such a talented cast to bring this script to life".
The story centers on the travails of Keaton's character, an actor who became famous for playing a superhero, as he tries to mount a Broadway play.
The cast includes Andrea Riseborough, Amy Ryan, Emma Stone and Naomi Watts.
Collaborating with Iñarritu on the script were Nicolas Giacobone, Alexander Dinelaris, and Armando Bo.
Giacobone and Bo also worked with Iñarritu on the script for "Biutiful".