Written by Phillips and Scott Silver, who also helped pen Joker, the script is dated May 18 2022.
The original film followed the life of the tortured wannabe comedian Arthur Fleck, whose feelings of being downtrodden by society ultimately transform him into the infamous criminal mastermind.
As well as Phoenix, who played the title role, the film’s cast included Robert De Niro and Zazie Beetz.
Phillips shared a picture of a script to Instagram on Tuesday, as well as another with star of the original, Joaquin Phoenix (pictured), reading it (Ian West/PA)
The film was nominated for 11 Academy awards, winning Oscars for best original score and best actor for Phoenix.
The actor also won best actor accolades at the Baftas, the Critic’s Choice Awards (CCA), Golden Globes, and Screen Actors Guild (SAG) awards.
Joker director Todd Phillips reveals sequel is in the works