John Carter star Taylor Kitsch has joined the cast of the upcoming HBO TV movie The Normal Heart, directed by Glee and American Horror Story creator Ryan Murphy.

The actor will portray Bruce Niles, a gay investment banker who is in the closet, who becomes a powerful AIDS activist. Lee Pace originally portrayed the character in Larry Kramer's Tony-award winning play. Larry Kramer also wrote the screenplay adaptation. The story is set in 1980s New York City, during the HIV/AIDS crisis that galvanized the nation.

Mark Ruffalo is portraying Ned Weeks, who witnesses what this deadly disease can do first-hand, when several of his friends begin passing away. Matthew Bomer portrays Felix Turner, a reporter who becomes Ned's lover. Julia Roberts is playing Dr. Emma Brookner, a paraplegic physician who treated many of the first AIDS patients. Alec Baldwin and Jim Parsons also star.

The project was initially slated for a theatrical debut, before HBO Films acquired the project in January. Production will begin later this year, with the movie slated to debut in 2014 on HBO.