Taylor Kitsch and Jim Parsons join 'The Normal Heart' at HBO

HBO has added two more stars to the cast of "The Normal Heart," an adaptation of Larry Kramer's play to be directed by Ryan Murphy.

"The Big Bang Theory" star Jim Parsons and Taylor Kitsch ("Battleship," "Friday Night Lights") will star alongside Julia Roberts, Mark Ruffalo and Matt Bomer in the movie, Deadline reports. "The Normal Heart" is set in the early days of the AIDS crisis in New York.

Parsons will play activist Tommy Boatwright in the movie -- the same role he played when the play was staged on Broadway in 2011. Kitsch will play Bruce Niles, an in-the-closet banker who later becomes an AIDS activist.

Kramer is adapting his play for HBO, with Murphy directing. Production is scheduled to start later this year for a 2014 premiere on HBO.