When The Lost City of Z was first in development, Pitt was supposed to star in the role ultimately played by Charlie Hunnam (Pacific Rim).
One possibility is Ad Astra, as far as what Pitt may be starring in next goes.
This would not be the first time Pitt and and Gray have worked together.
Ad Astra would see Pitt playing Roy McBride, a mildly autistic space engineer traveling through the solar system in search of his father, who disappeared on a mission to Neptune twenty years previous in search of extraterrestrial life.