The project comes from Glee co-creator Ryan Murphy and executive producer Lauren Gussis (Dexter).
Open is described as a modern-day exploration of human sexuality and relationships, The Wrap reports.
Additional plot details surrounding the pilot are currently being kept under wraps.
Leigh and Torv are slated to play Windsor and Holly, a troubled lesbian couple.
Actors Wes Bentley (The Hunger Games) and Scott Speedman (Underworld) have previously been cast.
Bentley will take the lead role of Evan Foster with Speedman set to play the character Jonathan.
Leigh has recently been seen in ABC's Revenge and the Showtime series Weeds.
Torv's credits include the Fox sci-fi series Fringe with an upcoming voice role in Heavenly Sword.